Seena Dehkharghani MD FAHA

All Publications

• Computed Tomography-Based Imaging Scores in Basilar Artery Occlusions: A Comparison of Predictive Abilities for Functional Outcomes STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY Lun, R., Shah, P., Franco, L., Cereda, C. W., Mlynash, M., Yuen, N., Qureshi, A. Y., Hinduja, A., Dehkharghani, S., Goldman Yassen, A. E., Hsieh, K., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T. D., Fiehler, J., Pileggi, M., Campbell, B., Wells, C., Heit, J. J., Albers, G. W. 2026; 6 (5)

  View details for DOI 10.1161/SVIN.125.002185

  View details for Web of Science ID 001868309500011

• Editorial for "Structural Magnetic Resonance Imaging Volumetry Index for Differentiation of Progressive Supranuclear Palsy From Parkinson's Disease, and Multiple System Atrophy by Automatic Segmentation, A Comparison With Magnetic Resonance Parkinsonism Index". Journal of magnetic resonance imaging : JMRI Benitez, S., Dehkharghani, S. 2026

  View details for DOI 10.1002/jmri.70486

  View details for PubMedID 42596062

• Detection and localization of posterior circulation large vessel occlusions using perfusion imaging. Journal of neurointerventional surgery Talati, I. A., Schwartz, M., Mlynash, M., Seners, P., Vandewalle, L., Cereda, C. W., Yuen, N., Rhodes, S., Faizy, T. D., Yedavalli, V., Dehkharghani, S., Zeno, B., Lansberg, M. G., Albers, G. W., Heit, J. J. 2026

  Abstract

  Cerebral perfusion imaging may help detect the presence of, and infer vessel occlusion location in, anterior circulation stroke, but its value in posterior circulation large vessel occlusion (PC-LVO) is less well defined. We evaluated the accuracy and inter-reader reliability of CT and MR perfusion imaging for occlusion classification and posterior circulation vessel localization.We performed a retrospective multicenter diagnostic accuracy study from 11 centers that underwent perfusion imaging for stroke evaluation. The cohort was enriched for posterior circulation stroke. Four blinded readers assigned each case to one of five categories: no occlusion, anterior circulation large vessel occlusion (AC-LVO), basilar artery, posterior cerebral artery (PCA), or vertebral/posterior inferior cerebellar artery (vert/PICA) occlusion. Final classification was determined by majority vote.184 patients were included. Perfusion imaging correctly classified 150/184 cases on the 5-class task (81.5%, 95% CI 75.1% to 86.9%). Across the 3-class task of LVO(-), AC-LVO, and PC-LVO, accuracy was 163/184 (88.6%, 95% CI 83.1% to 92.8%), with sensitivity of 100% for LVO(-), 100% for AC-LVO, and 84.4% for PC-LVO. Within the posterior circulation subgroup, perfusion imaging correctly localized basilar, PCA, and vert/PICA occlusions in 101/135 cases (74.8%, 95% CI 66.6% to 81.9%), including 82/107 basilar (76.6%), 10/12 PCA (83.3%), and 9/16 vert/PICA (56.3%). Fleiss κ was 0.889 for the 3-class task, 0.742 for the 5-class task, and 0.604 for posterior localization.Perfusion imaging is moderately accurate for the detection and localization of PC-LVO, but performs less well compared with the detection of AC-LVO.

  View details for DOI 10.1136/jnis-2026-025637

  View details for PubMedID 42463244

• Editorial for "Infant Brain Age Estimation With T1w/T2w Ratio MRI: A Myelination-Aware Deep Learning Approach". Journal of magnetic resonance imaging : JMRI Soares, B. P., Dehkharghani, S. 2026

  View details for DOI 10.1002/jmri.70381

  View details for PubMedID 42319175

• Infant Brain Age Estimation With T1w/T2w Ratio MRI: A Myelination-Aware Deep Learning Approach JOURNAL OF MAGNETIC RESONANCE IMAGING Park, H., Choi, Y., Gho, S. 2026

  Abstract

  Brain age estimation provides a noninvasive MRI biomarker of neurodevelopment. In infancy, rapid regionally ordered myelination reflects brain maturation, yet early-life brain age estimation remains underexplored, particularly with myelination-sensitive MRI and biologically informed modeling.To develop and evaluate a biologically informed deep learning framework for infant brain age estimation using T1w/T2w ratio MRI.Retrospective.Internal cohort: 629 infants aged 0-24 months (626 with age-appropriate myelination, train/validation/test = 376/125/125), 3 with myelin-related developmental abnormalities for qualitative review. External cohort: 10 healthy infants aged 0-15 months (5 females, 5 males).Internal: 3T; 3D gradient-echo or 2D spin-echo T1w, and 2D turbo spin-echo T2w. External: 3T; 3D gradient-echo T1w and 2D turbo spin-echo T2w.3D convolutional neural networks were trained with T1w, T2w, and T1w/T2w ratio inputs using manually defined biological age labels from visual myelination assessment. The model incorporated multi-task learning for age regression, white matter segmentation, and image reconstruction.Performance was evaluated using five-fold cross-validation with repeated random splits. Metrics included mean absolute error, root mean squared error, R 2 $$ {R}^2 $$ , and Pearson and Spearman correlations. Modality differences were tested using one-way ANOVA, t $$ t $$ -tests, and Mann-Whitney U $$ U $$ , with Cohen's d $$ d $$ and 95% confidence intervals. In the external cohort, absolute prediction errors were compared using the Wilcoxon signed-rank test. Statistical significance was defined as p < 0.05 $$ p<0.05 $$ .T1w/T2w ratio models achieved the best overall performance (MAE: 1.489  ± $$ \pm $$ 0.302 months; r $$ r $$  = 0.966  ± $$ \pm $$  0.012), compared with T1w (2.055  ± $$ \pm $$  0.944; 0.933  ± $$ \pm $$  0.061), T2w (1.794  ± $$ \pm $$  0.434; 0.947  ± $$ \pm $$  0.023), T1w+T2w (1.546  ± $$ \pm $$  0.291; 0.960  ± $$ \pm $$  0.013), and T1w+T2w+RI (1.498  ± $$ \pm $$  0.313; 0.963 ± $$ \pm $$ 0.012). Modality effects were significant for MAE, RMSE, R 2 $$ {R}^2 $$ , r $$ r $$ , but not for ρ $$ \rho $$ ( p = 0.250 $$ p=0.250 $$ ). Auxiliary-task and multi-scale modeling numerically improved performance (MAE, 1.203 months; r $$ r $$  = 0.979). External validation showed the lowest error for the RI-based model (MAE, 1.16 months), and Grad-CAM highlighted myelination-relevant white matter.T1w/T2w ratio MRI combined with biologically informed deep learning enabled accurate and interpretable infant brain age estimation. This framework showed promising cross-scanner performance and may support MRI-based assessment of early brain maturation.3.2.

  View details for DOI 10.1002/jmri.70376

  View details for Web of Science ID 001786076100001

  View details for PubMedID 42247370

• A Data-Driven Normalization Framework for Subject-Specific Cerebrovascular Reactivity Assessment in Cerebrovascular Disease. Journal of magnetic resonance imaging : JMRI Zhu, Y., Dogra, S., Wang, X., Polimeni, J. R., Dehkharghani, S. 2026

  Abstract

  Assessment of cerebrovascular reactivity (CVR) has been reported using acetazolamide-augmented blood oxygenation level-dependent (BOLD) MRI; however, wide intersubject baseline variability can complicate interpretation.To develop an integrated normalization framework combining machine learning-guided identification of healthy voxels for subject-specific baseline rescaling with atlas-based assessment.Retrospective.26 subjects (age 51 ± 13 at first scan, 50% women, 34 exams) with unilateral steno-occlusive disease (SOD) and 9 subjects with bilateral disease (age 55 ± 12, 4/9 women) underwent acetazolamide-augmented BOLD-MRI.T1-weighted MPRAGE (1 mm isotropic) and gradient-echo EPI at 3 T.Machine learning models (random forest, XGBoost, LightGBM, and neural networks) were trained to identify healthy candidate voxels using a previously reported pipeline based on baseline resting-state BOLD temporal shift features derived from 32 arterial territories. A healthy reference CVR atlas was constructed from unaffected hemispheres. Individual CVR maps were rescaled using predicted healthy voxels and converted to Z-scores and risk index maps using the reference atlas.Coefficient of variation (CV) within normal hemispheres, lesion contrast-to-noise ratio (CNR), Lesion ROC AUC, asymmetry index (AI) in unilateral patients, and chi-square distance between thresholded normal and abnormal CVR distributions across all patients were compared between atlas-based group normalization alone and the proposed integrated normalization using paired t-tests. (cutoff p = 0.05).CV within normal hemispheres significantly decreased (1.07 ± 0.15 vs. 0.45 ± 0.09), indicating improved inter-subject stability. Lesion CNR and ROC AUC improved across all impairment thresholds (CNR: 0.73-1.12 vs. 0.79-1.19; AUC: 0.76-0.89 vs. 0.81-0.90). AI increased significantly at higher risk thresholds (≥ 0.78), with no significant difference at the lowest threshold (p = 0.181). Chi-square analysis demonstrated significantly increased separation between CVR distributions at intermediate thresholds.The proposed integrated normalization improves the stability, discriminability, and interpretability of acetazolamide-augmented BOLD-CVR for detection of cerebrovascular impairment.3.Stage 2.

  View details for DOI 10.1002/jmri.70388

  View details for PubMedID 42233513

• Microcirculatory Collaterals Modulate Ischemic Core Heterogeneity on Diffusion-Weighted Imaging. AJNR. American journal of neuroradiology Zamarud, A., Mlynash, M., Yuen, N., van Voorst, H., Ter Schiphorst, A., Seners, P., Wouters, A., Schwartz, M., Albers, G. W., Campbell, B., Dehkharghani, S., Lansberg, M. G., Heit, J. J. 2026

  Abstract

  Endovascular thrombectomy (EVT) is an effective treatment for acute ischemic stroke due to large vessel occlusion (AIS-LVO). The ischemic core is best determined on DWI, which is commonly thresholded for automated analysis using ADC maps. However, there may be substantial heterogeneity in ADC values within the ischemic core. We determined how tissue-level collaterals, measured by hypoperfusion intensity ratio (HIR) on cerebral perfusion imaging, influences ischemic core heterogeneity.We performed a post hoc analysis of the CT Perfusion to Predict Response to Recanalization in Ischemic Stroke Project 2 (CRISP 2) study of patients with AIS-LVO who underwent baseline CT/CTP and follow-up MRI/MR perfusion (MRP) prior to EVT. Patients were dichotomized into favorable (HIR ≤0.5) and unfavorable (HIR >0.5) groups, and variability in ADC reduction was determined across an ischemic core defined by standard thresholds of ADC ≤620 × 10-6 mm²/s.One hundred ninety-seven CRISP 2 patients met criteria: 113 (57%) favorable HIR and 84 (43%) unfavorable HIR. Favorable HIR patients had lower baseline NIHSS scores (median 14 versus 16; P = .012), smaller hypoperfusion volumes (time-to-maximum >6 seconds and >10 seconds), smaller ischemic core volumes (27 mL versus 50 mL; P < .001), and were less frequently treated with IV thrombolysis (29% versus 45%; P = .016). ADC heterogeneity was lower in favorable HIR (standard deviation: 167.2 versus 193.5; P = .01), but the mean ADC was similar between groups. Clinical outcomes were not different between favorable and unfavorable HIR groups. Multivariable analysis showed HIR was independently associated with ADC standard deviation (P = .002) and coefficient of variation (P = .003) at the comprehensive stroke center.Favorable tissue-level collaterals (low HIR) are associated with reduced ischemic core ADC heterogeneity.

  View details for DOI 10.3174/ajnr.A9178

  View details for PubMedID 42062038

• 3D foundation model for generalizable disease detection in head computed tomography NATURE BIOMEDICAL ENGINEERING Zhu, W., Huang, H., Tang, H., Musthyala, R., Yu, B., Chen, L., Vega, E., O'Donnell, T., Hayek, R., Kuohn, L., Dehkharghani, S., Frontera, J. A., Masurkar, A. V., Melmed, K., Razavian, N. 2026

  Abstract

  Head computed tomography (CT) imaging is a widely used imaging modality with multitudes of medical indications, particularly in assessing pathology of the brain, skull and cerebrovascular system. It is commonly used as the first-line imaging in neurologic emergencies given its rapidity of image acquisition, safety, cost and ubiquity. Deep learning models may facilitate detection of a wide range of diseases. However, the scarcity of high-quality labels and annotations, particularly among less common conditions, substantially hinders the development of powerful models. To address this challenge, we introduce FM-HCT, a Foundation Model for Head CT for generalizable disease detection, trained using self-supervised learning. Our approach pretrains a deep learning model on a large, diverse dataset of 361,663 non-contrast 3D head CT scans without the need for manual annotations, enabling the model to learn robust, generalizable features. Our results demonstrate that the self-supervised foundation model substantially improves performance on downstream diagnostic tasks compared to models trained from scratch and previous 3D CT foundation models trained on scarce annotated datasets.

  View details for DOI 10.1038/s41551-026-01668-w

  View details for Web of Science ID 001745910200001

  View details for PubMedID 42020556

  View details for PubMedCentralID 8377493

• Deep learning-based non-contrast CT imaging markers enhance post-transfer DWI core volume prediction. AJNR. American journal of neuroradiology van Voorst, H., Konduri, P., Ter Schiphorst, A., Vandewalle, L., Liu, Y., Jiang, B., Heylen, E., Mlynash, M., Christensen, S., Dehkharghani, S., Albers, G. W., Zaharchuk, G., Lansberg, M. G., Heit, J. J. 2026

  Abstract

  BACKGROUND: Deep learning enables the extraction of ischemic lesion size and hypodensity imaging markers from noncontrast CT (DLNCCT) in patients with acute ischemic stroke, but it remains unclear whether those markers can predict post-transfer core volume.METHODS: We performed a post-hoc analysis of prospectively enrolled patients transferred from a primary to a comprehensive center (PSC/CSC) for endovascular treatment (EVT). Using a validated deep-learning NCCT segmentation method, we quantified total lesion volume (per 10mL), modified net water uptake (mNWU %), and severely hypodense volume (≤26 HU per 10mL) and compared these markers with core-lab-rated ASPECTS (per point decrease) and CTP-based evaluation for their association with (adjusted regression coefficient [95%CI]) and predictive performance in addition to baseline variables (R2±SE) for post-transfer CSC-admission DWI core volume.RESULTS: We included 420 patients (239[57%] males) with a median age of 72 years (IQR:61;80). We observed 11.2mL (95%CI:8.3;14.1] larger post-transfer core volumes per point decrease in ASPECTS, 10.0mL (95%CI:6.8;13.3) and 20.0mL (95%CI:12.7;27.2) larger post-transfer core volumes per 10 mL increase in total and severely hypodense DLNCCT volume, respectively. mNWU was not associated with post-transfer core volume (p=0.63). In addition to clinical baseline and CTA variables, post-transfer core volume prediction with ASPECTS (R2:0.49±0.02) and DLNCCT (R2:0.50±0.02) did not differ significantly (p=0.58). Compared with using CTP imaging markers (R2:0.56±0.02), adding ASPECTS (R2:0.63±0.02, p<0.01) and DLNCCT (R2:0.65±0.01, p<0.01) improved performance for post-transfer core volume prediction.CONCLUSION: Total and severely hypodense DLNCCT volumes are independent predictors for post-transfer core volume. These DLNCCT markers improved CTP-based post-transfer core volume prediction.

  View details for DOI 10.3174/ajnr.A9311

  View details for PubMedID 41916751

• Automated In-line Normalization Procedure for BOLD-CVR Using the Resting-State Temporal Shift with Machine Learning. AJNR. American journal of neuroradiology Zhu, Y., Dogra, S., Wang, X., Polimeni, J. R., Dehkharghani, S. 2026

  Abstract

  Cerebrovascular reactivity (CVR) is commonly used to estimate hemodynamic impairment. Conventional use is best suited to unilateral vascular disease, such that CVR can be normalized to reference values from the contralateral hemisphere or to posterior circulation territories; however, major confounds have been identified that leave implementation difficult in more common cases of bilateral disease, even despite common cerebellar normalization. Recently, we reported data-driven identification of candidate healthy voxel signatures learned from contemporaneous imaging data. Here, we introduce an entirely inline, automated approach exploiting the dynamics of resting-state BOLD (rs-BOLD) signal from the BOLD baseline, hypothesizing prediction to within ten percent error relative to ground truth healthy-voxel CVR values.22 subjects with strictly unilateral intracranial steno-occlusive disease (SOD) underwent 28 CVR studies under pharmacologic provocation using acetazolamide with BOLD-MRI (ACZ-BOLD). Separate affected and unaffected hemispheric masks were segmented to train machine learning models to learn signatures of the unaffected hemisphere using the rs-BOLD baseline, as well as anatomic and vascular parameters. Twenty additional healthy subjects from the Human Connectome Project supplemented training, wherein all voxels were classified normals. 32 distinct time-delays were computed voxelwise, with 32 maximum correlation values constrained to each of 32 paired arterial territories. Performance in prediction of ground-truth reference CVR was computed and compared.The ensembled model achieved AUC of 0.81 in predicting candidate unaffected voxels, demonstrating strong performance in estimation of normal-hemisphere CVR (median absolute percent error [95%CIs] 7.28[3.48-10.34] and 5.61[2.90-9.86] to predict median and mean reference CVR), exhibiting significant improvements over naïve whole-brain voxel selection (P=0.005 and P=0.048, respectively) or conventional cerebellar normalization (26.4[10.1-40.3] median and 27.6[23.7-33.2] mean). In nine bilateral cases assessed to illustrate potential use, the proportion of candidate voxels and corresponding volumes predicted by the ensembled model was significantly lower than in most healthy hemispheres, but yielded subjectively improved delineation of putatively abnormal regions.We demonstrate feasibility of learning unaffected reference voxel CVR signatures for BOLD-CVR MRI. The approach facilitates extension of brain CVR beyond existing constraints in subjects with bilateral disease.

  View details for DOI 10.3174/ajnr.A9267

  View details for PubMedID 41741218

• Perfusion Imaging Changes in Cerebral Venous Sinus Thrombosis Associated with Hemorrhage Sim, J., Ter Schiphorst, A., Lansberg, M., Dehkharghani, S., Heit, J., Albers, G. LIPPINCOTT WILLIAMS & WILKINS. 2026

  View details for DOI 10.1161/str.57.suppl_1.TP242

  View details for Web of Science ID 001690943600028

• Aggregate Multi-tiered Normalization to Enhance Detection of Impairment in Dynamic BOLD-CVR for Assessment of Hemodynamic Impairment Zhu, Y., Wang, X., Dogra, S., Voorst, H., Heylen, E., Konduri, P. R., Schiphorst, A., Heit, J., Lansberg, M., Albers, G., Dehkharghani, S. LIPPINCOTT WILLIAMS & WILKINS. 2026

  View details for DOI 10.1161/str.57.suppl_1.WP265

  View details for Web of Science ID 001690949600028

• Predicting infarct location and stroke severity from symptoms using language models: towards the next generation of vision models in acute stroke Canals, P., Van Voorst, H., Gonzalez, J., Rodrigo-Gisbert, M., Mayol, J., Albers, G., Lansberg, M., Dehkharghani, S., Ribo, M., Heit, J. LIPPINCOTT WILLIAMS & WILKINS. 2026

  View details for DOI 10.1161/str.57.suppl_1.WP300

  View details for Web of Science ID 001690945000048

• Deep learning based ischemic lesion markers on non-contrast head CT compared to CTP and DWI. medRxiv : the preprint server for health sciences van Voorst, H., Jiang, B., Konduri, P., Ter Schiphorst, A., Zamarud, A., Dehkharghani, S., vandeWalle, L., Heylen, E., Liu, Y., Mlynash, M., Christensen, S., Yuen, N., Verhaaren, B. F., Mahammedi, A., Michel, P., Wintermark, M., Albers, G. W., Zaharchuk, G., Lansberg, M. G., Heit, J. J. 2025

  Abstract

  Background: Quantification of ischemic brain tissue on non-contrast CT (NCCT) in acute ischemic stroke is challenging in the acute setting.Purpose: To compare the spatial overlap and imaging marker agreement of acute ischemic regions of interest (ROIs) using deep-learning NCCT (DLNCCT) versus manual NCCT, CTP, and DWI-based ischemic segmentations.Methods: We trained a deep learning model to segment ischemic ROIs using manual lesion annotations on admission NCCTs (DLNCCT). DLNCCT ischemic ROIs were compared with manual NCCT delineation, CTP (rCBF<30%/38%), and DWI within 5 hours after the NCCT or after recanalization in four external test sets. Spatial overlap was measured using the Dice Similarity Coefficient (DSC; mean±SD). For each ROI, we derived: average density (HU); modified net water uptake (mNWU in %); total volume (mL); and hypodense (<26HU) volume (mL), and assessed agreement via Bland-Altman (mean difference [95%CI]) and concordance correlation coefficient (CCC) analysis.Results: 218 training (n=104/89/25 male/female/unknown, mean age 68±14 years) and 762 test cases (n=243/206/313 male/female/unknown, mean age 70±15 years) were used. Spatial overlap was 0.30±0.30 between DLNCCT and manual segmentation, 0.22±0.25 between DLNCCT and DWI, 0.10±0.19/0.14±0.21 between DLNCCT and CTP (rCBF<30%/<38%), and 0.15±0.22/0.21±0.24 between CTP (rCBF<30%/<38%) and DWI. DLNCCT vs. DWI mean differences of ischemic ROI derived imaging markers were -1HU (95%CI:-7;6) for average density (CCC:0.71), 4.9% (95%CI:-7.0;16.8) for mNWU (CCC:0.35), -16mL (95%CI:-108;76) for total volume (CCC:0.57), and -4mL (95%CI:-31;23) for hypodense lesion volume (CCC: 0.75).Conclusion: Spatial overlap and agreement of imaging markers between DLNCCT and DWI ischemic ROIs were comparable to CTP and DWI.Summary Statement: Ischemic injury on NCCT is identified and quantified by a deep-learning model with accuracy similar to CTP and DWI in stroke patients with a large vessel occlusion.Key results: Deep-learning models can segment ischemic brain tissue on NCCT.Ischemic regions identified by our model demonstrate comparable overlap with ischemic core segmentation on CTP (Dice: 0.21±0.24) and DWI (Dice: 0.22±0.25).Deep learning NCCT showed high agreement with follow-up DWI in determining the hypodense (<26 HU) lesion volume (mean difference -4mL [95%CI:-31;23], CCC: 0.75).

  View details for DOI 10.1101/2025.11.18.25340504

  View details for PubMedID 41332814

• Multi-modal proton and sodium MRI for outcome prediction in mild traumatic brain injury. Journal of neurology Chen, A. M., Gerhalter, T., Ma, Z., Gajdošík, M., Dehkharghani, S., Peralta, R., Gajdošík, M., Sheriff, S., Ahn, S., Li, X., Goldberg, J. D., Bushnik, T., Zarate, A., Silver, J. M., Im, B. S., Wall, S. P., Cloos, M. A., Baete, S., Brown, R., Madelin, G., Kirov, I. I. 2025; 272 (9): 569

  Abstract

  In mild traumatic brain injury, imaging biomarkers are needed to support clinical management. In four antecedent publications, we used two new (sodium and fingerprinting) and two established (spectroscopy and diffusion) MR techniques in a longitudinally followed patient cohort. Here we report final results and combine all data to determine which marker(s) from the four modalities offer the greatest utility for detecting injury and predicting outcomes. We also leverage the independent specificities offered by each modality to explore injury mechanisms.The longitudinal spectroscopy data were analysed to complete a full data set of proton (spectroscopy, fingerprinting, diffusion) and sodium MRI, acquired alongside symptomatic, cognitive, and functional assessments in 27 patients at 1, 3, and 12 months following injury. Twenty-three matched controls were scanned once. Testing for associations between nine MR markers and three outcome measures was standardized across the entire data set, and performed using Spearman correlations and logistic regression.Previously elevated white matter choline and creatine from spectroscopy (markers of membrane turnover and cellular energetics, respectively) normalized to control levels by 3 months, at rates which correlated with the rate of symptom recovery. Sodium and spectroscopy showed findings coinciding in pattern and timepoint, but there were no associations between them, suggesting independent origin. Choline and creatine met the greatest number of biomarker properties, followed by water T1 from fingerprinting (marker of the cellular microenvironment).We identified independent, dynamic, metabolic and ionic changes, with choline and creatine from spectroscopy fulfilling the most criteria for a clinical biomarker.

  View details for DOI 10.1007/s00415-025-13295-7

  View details for PubMedID 40794310

  View details for PubMedCentralID 3880097

• Visualization and Assessment of the Venous Plexus of Rektorzik on Ultrahigh Resolution Vessel Wall MRI. Journal of magnetic resonance imaging : JMRI Dogra, S., Raz, E., Dehkharghani, S. 2025

  View details for DOI 10.1002/jmri.70016

  View details for PubMedID 40552778

• Enhancing precision in aneurysm volume measurement: A comparative study of techniques including an artificial intelligence-based method for endovascular coiling. Surgical neurology international Tatit, R. T., Baccin, C. E., Nair, P., Mensah, E. O., Mason, J. R., Dehkharghani, S., Copeland, K., Ogilvy, C. S. 2025; 16: 213

  Abstract

  Durable occlusion after endovascular coiling can be compromised by recanalization, underscoring the need for accurate cerebral aneurysm assessment. Precise volume measurement not only informs treatment decisions and detects subtle aneurysm growth but also refines calculations of packing density, historically linked to occlusion success. This study compares three volume-measurement approaches-traditional two-dimensional (2D) estimation, a semi-automated three-dimensional (3D) technique, and an artificial intelligence (AI)-based 3D method.In this retrospective analysis, 24 aneurysms were assessed using 3D rotational angiography. Manual segmentation by three specialists using ITK-SNAP or mimics served as the reference standard. These results were compared with volumes from a semi-automated 3D platform (Philips Advanced Visualization Workspace), an AI-based tool (RapidAI for Aneurysm), and traditional 2D estimations. Agreement with the reference standard was quantified through Passing-Bablok regression slopes and mean biases.Passing-Bablok slopes for the 2D, Philips, and RapidAI methods were 0.83, 0.87, and 0.94, respectively, while mean biases were -24.7 mm3 (2D), -19.5 mm3 (Philips), and -14.5 mm3 (RapidAI). RapidAI demonstrated the strongest correlation with the reference standard, whereas 2D estimations showed the largest discrepancy. The semi-automated 3D method exhibited intermediate accuracy, potentially influenced by the clinician input required for segmentation.All methods underestimated aneurysm volumes compared to the reference standard, suggesting that inaccurate volume measurements may mask early aneurysm growth. Among the techniques assessed, the AI-based approach provided the closest agreement with the reference, indicating that improved volumetric methods-particularly AI-driven ones-can enhance early detection of aneurysm expansion, guide treatment decisions, and help establish more reliable follow-up strategies for both treated and conservatively managed aneurysms.

  View details for DOI 10.25259/SNI_1118_2024

  View details for PubMedID 40469319

  View details for PubMedCentralID PMC12134790

• Using Data-Driven Methods to Improve Brain Blood Flow Measurements in Cerebrovascular Disease with Dynamic Imaging. AJNR. American journal of neuroradiology Dogra, S., Wang, X., Gee, J. M., Zhu, Y., Ishida, K., Dehkharghani, S. 2025

  Abstract

  Cerebrovascular reactivity (CVR) is a widely studied biomarker of cerebral hemodynamics, commonly used in risk stratification and treatment planning in patients with steno-occlusive disease (SOD). Conventional use relies on normalization of estimates to contralateral hemisphere reference values, which is unsuitable for bilateral or indeterminate distributions of disease. We report upon a custom data-driven approach leveraging random forest classifiers (RFc) to identify candidate voxels for normalization in order to facilitate interrogation outside conditions of known unilateral SOD MATERIALS AND METHODS: We retrospectively analyzed 16 patients with unilateral SOD who underwent acetazolamide-augmented BOLD-MRI and DSC perfusion. Three RFc models were trained using leave-one-out cross-validation (LOOCV) to identify candidate voxels brain-wide whose CVR were within 10% of the normal hemispheric median: i. all voxels; ii. gray matter only; and iii. white matter only. Model input features included time-to-maximum (Tmax), mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) from contemporaneous DSC. The median model-predicted reference CVR (CVRref) was compared to ground-truth medians in LOOCV, and its impact on threshold-based volumetric classification of CVR reduction assessed.RFc models effectively predicted ground-truth CVR voxels, achieving median absolute percent differences of 12.8% (IQR: 5.0%-18.9%) using all voxels, 11.3% (IQR: 9.3%-16.1%) for gray matter, and 9.8% (IQR: 4.4%-16.9%) for white matter. Volumetric estimates of CVR reduction across thresholds for the models revealed excellent agreement between ground-truth and model estimates without statistically significant differences (p>0.01), excepting lowest white matter CVR thresholds. Model use in a small pilot deployment of bilateral SOD cases demonstrated the potential utility, enabling voxel-wise CVR assessment without reliance on contralateral reference.We present a novel data-driven approach for normalizing CVR maps in patients with bilateral or indeterminate SOD. Using an RFc, our method provides an individualized, brain-wide reference CVR, expanding the utility of CVR estimates beyond the typical constraints of unilateral disease, and with potential application to other, similarly constrained scenarios such as for SPECT or PET hemodynamic studies.CVR = cerebrovascular reactivity; RFc = random forest classifier; SOD = steno-occlusive disease.

  View details for DOI 10.3174/ajnr.A8813

  View details for PubMedID 40262947

• Predicting hematoma expansion after intracerebral hemorrhage: a comparison of clinician prediction with deep learning radiomics models NEUROCRITICAL CARE Yu, B., Melmed, K. R., Frontera, J., Zhu, W., Huang, H., Qureshi, A. I., Maggard, A., Steinhof, M., Kuohn, L., Kumar, A., Berson, E. R., Tran, A. T., Payabvash, S., Ironside, N., Brush, B., Dehkharghani, S., Razavian, N., Ranganath, R. 2025; 43 (1): 119-129

  Abstract

  Early prediction of hematoma expansion (HE) following nontraumatic intracerebral hemorrhage (ICH) may inform preemptive therapeutic interventions. We sought to identify how accurately machine learning (ML) radiomics models predict HE compared with expert clinicians using head computed tomography (HCT).We used data from 900 study participants with ICH enrolled in the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 Study. ML models were developed using baseline HCT images, as well as admission clinical data in a training cohort (n = 621), and their performance was evaluated in an independent test cohort (n = 279) to predict HE (defined as HE by 33% or > 6 mL at 24 h). We simultaneously surveyed expert clinicians and asked them to predict HE using the same initial HCT images and clinical data. Area under the receiver operating characteristic curve (AUC) were compared between clinician predictions, ML models using radiomic data only (a random forest classifier and a deep learning imaging model) and ML models using both radiomic and clinical data (three random forest classifier models using different feature combinations). Kappa values comparing interrater reliability among expert clinicians were calculated. The best performing model was compared with clinical predication.The AUC for expert clinician prediction of HE was 0.591, with a kappa of 0.156 for interrater variability, compared with ML models using radiomic data only (a deep learning model using image input, AUC 0.680) and using both radiomic and clinical data (a random forest model, AUC 0.677). The intraclass correlation coefficient for clinical judgment and the best performing ML model was 0.47 (95% confidence interval 0.23-0.75).We introduced supervised ML algorithms demonstrating that HE prediction may outperform practicing clinicians. Despite overall moderate AUCs, our results set a new relative benchmark for performance in these tasks that even expert clinicians find challenging. These results emphasize the need for continued improvements and further enhanced clinical decision support to optimally manage patients with ICH.

  View details for DOI 10.1007/s12028-025-02214-3

  View details for Web of Science ID 001416362200001

  View details for PubMedID 39920546

• Computed-Tomography (CT) Based Imaging Scores in Basilar Artery Occlusions - A Comparison of Predictive Abilities for Functional Outcomes Lun, R., Shah, P., Franco, L., Cereda, C., Mlynash, M., Yuen, N., Qureshi, A., Hinduja, A., Dehkharghani, S., Yassen, A., Hsieh, K., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T., Fiehler, J., Pileggi, M., Campbell, B., Heit, J., Albers, G. LIPPINCOTT WILLIAMS & WILKINS. 2025

  View details for DOI 10.1161/str.56.suppl_1.TP165

  View details for Web of Science ID 001435578701043

• Computed Tomography Perfusion-Based Imaging Score Outperform Other Imaging Scores in Basilar Artery Occlusions - An Agreement Study Lun, R., Shah, P., Franco, L., Cereda, C., Mlynash, M., Yuen, N., Qureshi, A., Hinduja, A., Dehkharghani, S., Yassen, A., Hsieh, K., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T., Fiehler, J., Pileggi, M., Campbell, B., Albers, G., Heit, J. LIPPINCOTT WILLIAMS & WILKINS. 2025

  View details for DOI 10.1161/str.56.suppl_1.WP202

  View details for Web of Science ID 001435578702110

• Towards a Comprehensive Computational Model of Ischemic Stroke: Integrating Detailed Microvasculature With Advanced Model of Brain Tissue Metabolism Dehkharghani, S., Brantner, D., Ventimiglia, T., Collins, C., Linninger, A. LIPPINCOTT WILLIAMS & WILKINS. 2025

  View details for DOI 10.1161/str.56.suppl_1.WMP115

  View details for Web of Science ID 001435578701378

• Association of anaesthesia-directed sedation with unplanned discharge to a nursing home following non-ambulatory interventional radiology and endoscopic procedures: a retrospective cohort study ANAESTHESIA Eyth, A., Borngaesser, F., Zmily, O. M., Rudolph, M. I., Zhang, L., Joseph, V. A., Evgenov, O. V., Oliveira, J., Kolmel, N., Dehkharghani, S., Osborn, I., Kiyatkin, M. E., Racine, A. D., Semczuk, P. P., Garg, S., Wongtangman, K., Eikermann, M., Karaye, I. M. 2025; 80 (3): 288-298

  Abstract

  Interventional radiology procedures and endoscopies are performed commonly worldwide, often necessitating pharmacological sedation to optimise patient comfort. It is unclear to what extent non-anaesthetists should provide procedural sedation.We studied adult patients who previously lived independently and underwent a non-ambulatory interventional radiology or gastroenterology procedure under anaesthetist-directed or non-anaesthetist-directed sedation at a large healthcare network. The primary outcomes were postprocedural adverse discharge to a nursing home and postprocedural duration of hospital stay.Among 22,868 patients included, 15,168 (66.3%) and 7700 (33.7%) underwent anaesthetist-directed sedation and non-anaesthetist-directed sedation, respectively. Of all patients receiving anaesthetist-directed sedation, 9.2% experienced adverse discharge to a nursing home compared with 21.3% undergoing non-anaesthetist-directed sedation. Anaesthetist-directed sedation was associated with reduced risk of adverse discharge to a nursing home (adjusted relative risk 0.54, 95%CI 0.45-0.63, p < 0.001, adjusted risk difference -4.6%, 95%CI -5.8 to -3.4, p < 0.001) and a shorter postprocedural duration of hospital stay (median (IQR [range]) 2 (1-6 [0-315]) days vs. 5 (2-12 [0-268]) days; adjusted model estimate 0.84, 95%CI 0.79-0.89, p < 0.001). The lower risk of adverse discharge to a nursing home and shorter duration of hospital stay in patients undergoing anaesthetist-directed sedation was reproduced in an instrumental variable analysis (adjusted risk difference -4.3%, 95%CI -8.4 to -0.1, p = 0.043; and -1.41 days, 95%CI -1.43 to -1.41 days, p < 0.001, respectively). Among patients undergoing anaesthetist-directed sedation the mean (SD) proportion of missing blood pressure measurements was lower (0.7 (4.9) % vs. 8.0 (14.6) %, p < 0.001), which mediated the effect of anaesthetist-directed sedation on adverse discharge.Among patients undergoing a non-ambulatory interventional radiology procedure or a gastrointestinal endoscopy, anaesthetist-directed sedation is associated with a reduced risk of adverse discharge to a nursing home and a shorter duration of hospital stay.

  View details for DOI 10.1111/anae.16497

  View details for Web of Science ID 001371477400001

  View details for PubMedID 39638359

• Editorial for "Assessment the Impact of IDH Mutation Status on MRI Assessments of White Matter Integrity in Glioma Patients: Insights From Peak Width of Skeletonized Mean Diffusivity and Free Water Metrics" JOURNAL OF MAGNETIC RESONANCE IMAGING Benitez, S., Dehkharghani, S. 2025; 61 (3): 1201-1202

  View details for DOI 10.1002/jmri.29651

  View details for Web of Science ID 001361269800001

  View details for PubMedID 39570106

• An experimental system for detection and localization of hemorrhage using ultra-wideband microwaves with deep learning COMMUNICATIONS ENGINEERING Hedayati, E., Safari, F., Verghese, G., Ciancia, V. R., Sodickson, D. K., Dehkharghani, S., Alon, L. 2024; 3 (1): 126

  Abstract

  Stroke is a leading cause of mortality and disability. Emergent diagnosis and intervention are critical, and predicated upon initial brain imaging; however, existing clinical imaging modalities are generally costly, immobile, and demand highly specialized operation and interpretation. Low-energy microwaves have been explored as a low-cost, small form factor, fast, and safe probe for tissue dielectric properties measurements, with both imaging and diagnostic potential. Nevertheless, challenges inherent to microwave reconstruction have impeded progress, hence conduction of microwave imaging remains an elusive scientific aim. Herein, we introduce a dedicated experimental framework comprising a robotic navigation system to translate blood-mimicking phantoms within a human head model. An 8-element ultra-wideband array of modified antipodal Vivaldi antennas was developed and driven by a two-port vector network analyzer spanning 0.6-9.0 GHz at an operating power of 1 mW. Complex scattering parameters were measured, and dielectric signatures of hemorrhage were learned using a dedicated deep neural network for prediction of hemorrhage classes and localization. An overall sensitivity and specificity for detection >0.99 was observed, with Rayleigh mean localization error of 1.65 mm. The study establishes the feasibility of a robust experimental model and deep learning solution for ultra-wideband microwave stroke detection.

  View details for DOI 10.1038/s44172-024-00259-4

  View details for Web of Science ID 001478563600001

  View details for PubMedID 39242634

  View details for PubMedCentralID PMC11379885

• Correspondence on: 'Viz LVO versus Rapid LVO in detection of large vessel occlusion on CT angiography for acute stroke' by Delora <i>et al</i> JOURNAL OF NEUROINTERVENTIONAL SURGERY Yedavalli, V. S., Dehkharghani, S., Clemente, J. 2025; 17 (3): 334

  View details for DOI 10.1136/jnis-2024-022342

  View details for Web of Science ID 001309606400001

  View details for PubMedID 39237155

• ISMRM Clinical Focus Meeting 2023: "Imaging the Fire in the Brain" JOURNAL OF MAGNETIC RESONANCE IMAGING Agarwal, N., Fan, A., Huang, X., Dehkharghani, S., van der Kolk, A. 2025; 61 (4): 1580-1596

  Abstract

  Set during the Annual Meeting of the International Society for Magnetic Resonance in Medicine (ISMRM), the "Clinical Focus Meeting" (CFM) aims to bridge the gap between innovative magnetic resonance imaging (MRI) scientific research and daily patient care. This initiative is dedicated to maximizing the impact of MRI technology on healthcare outcomes for patients. At the 2023 Annual Meeting, clinicians and scientists from across the globe were invited to discuss neuroinflammation from various angles (entitled "Imaging the Fire in the Brain"). Topics ranged from fundamental mechanisms and biomarkers of neuroinflammation to the role of different contrast mechanisms, including both proton and non-proton techniques, in brain tumors, autoimmune disorders, and pediatric neuroinflammatory diseases. Discussions also delved into how systemic inflammation can trigger neuroinflammation and the role of the gut-brain axis in causing brain inflammation. Neuroinflammation arises from various external and internal factors and serves as a vital mechanism to mitigate tissue damage and provide neuroprotection. Nonetheless, excessive neuroinflammatory responses can lead to significant tissue injury and subsequent neurological impairments. Prolonged neuroinflammation can result in cellular apoptosis and neurodegeneration, posing severe consequences. MRI can be used to visualize these consequences, by detecting blood-brain barrier damage, characterizing brain lesions, quantifying edema, and identifying specific metabolites. It also facilitates monitoring of chronic changes in both the brain and spinal cord over time, potentially leading to better patient outcomes. This paper represents a summary of the 2023 CFM, and is intended to guide the enthusiastic MR user to several key and novel sequences that MRI offers to image pathophysiologic processes underlying acute and chronic neuroinflammation. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.

  View details for DOI 10.1002/jmri.29587

  View details for Web of Science ID 001300072500001

  View details for PubMedID 39193867

  View details for PubMedCentralID PMC11896938

• Longitudinal changes in sodium concentration and in clinical outcome in mild traumatic brain injury BRAIN COMMUNICATIONS Gerhalter, T., Chen, A. M., Dehkharghani, S., Peralta, R., Gajdosik, M., Zarate, A., Bushnik, T., Silver, J. M., Im, B. S., Wall, S. P., Madelin, G., Kirov, I. I. 2024; 6 (4): fcae229

  Abstract

  Ionic imbalances and sodium channel dysfunction, well-known sequelae of traumatic brain injury (TBI), promote functional impairment in affected subjects. Therefore, non-invasive measurement of sodium concentrations using 23Na MRI has the potential to detect clinically relevant injury and predict persistent symptoms. Recently, we reported diffusely lower apparent total sodium concentrations (aTSC) in mild TBI patients compared to controls, as well as correlations between lower aTSC and worse clinical outcomes. The main goal of this study was to determine whether these aTSC findings, and their changes over time, predict outcomes at 3- and 12-month from injury. Twenty-seven patients previously studied with 23Na MRI and outcome measures at 22 ± 10 days (average ± standard deviation) after injury (visit-1, v1) were contacted at 3- (visit-2, v2) and 12-month after injury (visit-3, v3) to complete the Rivermead post-concussion symptoms questionnaire (RPQ), the extended Glasgow outcome scale (GOSE), and the brief test of adult cognition by telephone (BTACT). Follow-up 1H and 23Na MRI were additionally scheduled at v2. Linear regression was used to calculate aTSC in global grey and white matters. Six hypotheses were tested in relation to the serial changes in outcome measures and in aTSC, and in relation to the cross-sectional and serial relationships between aTSC and outcome. Twenty patients contributed data at v2 and fifteen at v3. Total RPQ and composite BTACT z-scores differed significantly for v2 and v3 in comparison to v1 (each P < 0.01), reflecting longitudinally reduced symptomatology and improved performance on cognitive testing. No associations between aTSC and outcome were observed at v2. Previously lower grey and white matter aTSC normalized at v2 in comparison to controls, in line with a statistically detectable longitudinal increase in grey matter aTSC between v1 and v2 (P = 0.0004). aTSC values at v1 predicted a subset of future BTACT subtest scores, but not future RPQ scores nor GOSE-defined recovery status. Similarly, aTSC rates of change correlated with BTACT rates of change, but not with those of RPQ. Tissue aTSC, previously shown to be diffusely decreased compared to controls at v1, was no longer reduced by v2, suggesting normalization of the sodium ionic equilibrium. These changes were accompanied by marked improvement in outcome. The results support the notion that early aTSC from 23Na MRI predicts future BTACT, but not RPQ scores, nor future GOSE status.

  View details for DOI 10.1093/braincomms/fcae229

  View details for Web of Science ID 001272823300001

  View details for PubMedID 39035416

  View details for PubMedCentralID PMC11258572

• A Multiscale, Anatomically, and Neurochemically Realistic In Silico Toolbox for the Simulation of Cerebrovascular Ischemia Collins, C. M., Kancherla, J., Carluccio, G., Liang, J., Dehkharghani, S. LIPPINCOTT WILLIAMS & WILKINS. 2024

  View details for DOI 10.1161/str.55.suppl_1.WP28

  View details for Web of Science ID 001350230204114

• Novel Computational Framework for Modelling the Effects of Temperature on Survival Time in Ischemic Stroke Carluccio, G., Dehkharghani, S., Collins, C. LIPPINCOTT WILLIAMS & WILKINS. 2024

  View details for DOI 10.1161/str.55.suppl_1.WP311

  View details for Web of Science ID 001350230206080

• Performance of RAPID noncontrast CT stroke platform in large vessel occlusion and intracranial hemorrhage detection. Frontiers in neurology Yedavalli, V., Heit, J. J., Dehkharghani, S., Haerian, H., Mcmenamy, J., Honce, J., Timpone, V. M., Harnain, C., Kesselman, A., Filly, A., Beardsley, A., Sakamoto, B., Song, C., Montuori, J., Navot, B., Mena, F. V., Giurgiutiu, D. V., Kitamura, F., Lima, F. O., Silva, H., Mont'Alverne, F. J., Albers, G. 2023; 14: 1324088

  Abstract

  Noncontrast CT (NCCT) is used to evaluate for intracerebral hemorrhage (ICH) and ischemia in acute ischemic stroke (AIS). Large vessel occlusions (LVOs) are a major cause of AIS, but challenging to detect on NCCT.The purpose of this study is to evaluate an AI software called RAPID NCCT Stroke (RAPID, iSchemaView, Menlo Park, CA) for ICH and LVO detection compared to expert readers.In this IRB approved retrospective, multicenter study, stand-alone performance of the software was assessed based on the consensus of 3 neuroradiologists and sensitivity and specificity were determined. The platform's performance was then compared to interpretation by readers comprised of eight general radiologists (GR) and three neuroradiologists (NR) in detecting ICH and hyperdense vessel sign (HVS) indicating LVO.A total of 244 cases were included. Of the 244, 115 were LVOs and 26 were ICHs. One hundred three cases did not have LVO nor ICH. Stand-alone performance of the software demonstrated sensitivities and specificities of 96.2 and 99.5% for ICH and 63.5 and 95.1% for LVO detection. Compared to all 11 readers and eight GR readers only respectively, the software demonstrated superiority, achieving significantly higher sensitivities (63.5% versus 43.6%, p < 0.0001 and 63.5% versus 40.9%, p = 0.001).The RAPID NCCT Stroke platform demonstrates superior performance to radiologists for detecting LVO from a NCCT. Use of this software platform could lead to earlier LVO detection and expedited transfer of these patients to a thrombectomy capable center.

  View details for DOI 10.3389/fneur.2023.1324088

  View details for PubMedID 38156093

  View details for PubMedCentralID PMC10753184

• Decreasing false-positive detection of intracranial hemorrhage (ICH) using RAPID ICH 3. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association Sreekrishnan, A., Giurgiutiu, D., Kitamura, F., Martinelli, C., Abdala, N., Haerian, H., Dehkharghani, S., Kwok, K., Yedavalli, V., Heit, J. J. 2023; 32 (12): 107396

  Abstract

  INTRODUCTION: The prompt detection of intracranial hemorrhage (ICH) on a non-contrast head CT (NCCT) is critical for the appropriate triage of patients, particularly in high volume/high acuity settings. Several automated ICH detection tools have been introduced; however, at present, most suffer from suboptimal specificity leading to false-positive notifications.METHODS: NCCT scans from 4 large databases were evaluated for the presence of an ICH (IPH, IVH, SAH or SDH) of >0.4 ml using fully-automated RAPID ICH 3.0 as compared to consensus detection from at least two neuroradiology experts. Scans were excluded for (1) severe CT artifacts, (2) prior neurosurgical procedures, or (3) recent intravenous contrast. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by were determined.RESULTS: A total of 881 studies were included. The automated software correctly identified 453/463 ICH-positive cases and 416/418 ICH-negative cases, resulting in a sensitivity of 97.84% and specificity 99.52%, positive predictive value 99.56%, and negative predictive value 97.65% for ICH detection. The positive and negative likelihood ratios for ICH detection were similarly favorable at 204.49 and 0.02 respectively. Mean processing time was <40 seconds.CONCLUSIONS: In this large data set of nearly 900 patients, the automated software demonstrated high sensitivity and specificity for ICH detection, with rare false-positives.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2023.107396

  View details for PubMedID 37883825

• Autonomous animal heating and cooling system for temperature-regulated magnetic resonance experiments NMR IN BIOMEDICINE Verghese, G., Voroslakos, M., Markovic, S., Tal, A., Dehkharghani, S., Yaghmazadeh, O., Alon, L. 2024; 37 (2): e5046

  Abstract

  Temperature is a hallmark parameter influencing almost all magnetic resonance properties (e.g., T1 , T2 , proton density, and diffusion). In the preclinical setting, temperature has a large influence on animal physiology (e.g., respiration rate, heart rate, metabolism, and oxidative stress) and needs to be carefully regulated, especially when the animal is under anesthesia and thermoregulation is disrupted. We present an open-source heating and cooling system capable of regulating the temperature of the animal. The system was designed using Peltier modules capable of heating or cooling a circulating water bath with active temperature feedback. Feedback was obtained using a commercial thermistor, placed in the animal rectum, and a proportional-integral-derivative controller was used to modulate the temperature. Its operation was demonstrated in a phantom as well as in mouse and rat animal models, where the standard deviation of the temperature of the animal upon convergence was less than a 10th of a degree. An application where brain temperature of a mouse was modulated was demonstrated using an invasive optical probe and noninvasive magnetic resonance spectroscopic thermometry measurements.

  View details for DOI 10.1002/nbm.5046

  View details for Web of Science ID 001119444100001

  View details for PubMedID 37837254

  View details for PubMedCentralID PMC10840815

• An experimental system for detection and localization of hemorrhage using ultra-wideband microwaves with deep learning. ArXiv Hedayati, E., Safari, F., Verghese, G., Ciancia, V. R., Sodickson, D. K., Dehkharghani, S., Alon, L. 2023

  Abstract

  Stroke is a leading cause of mortality and disability. Emergent diagnosis and intervention are critical, and predicated upon initial brain imaging; however, existing clinical imaging modalities are generally costly, immobile, and demand highly specialized operation and interpretation. Low-energy microwaves have been explored as low-cost, small form factor, fast, and safe probes of tissue dielectric properties, with both imaging and diagnostic potential. Nevertheless, challenges inherent to microwave reconstruction have impeded progress, hence microwave imaging (MWI) remains an elusive scientific aim. Herein, we introduce a dedicated experimental framework comprising a robotic navigation system to translate blood-mimicking phantoms within an anatomically realistic human head model. An 8-element ultra-wideband (UWB) array of modified antipodal Vivaldi antennas was developed and driven by a two-port vector network analyzer spanning 0.6-9.0 GHz at an operating power of 1 mw. Complex scattering parameters were measured, and dielectric signatures of hemorrhage were learned using a dedicated deep neural network for prediction of hemorrhage classes and localization. An overall sensitivity and specificity for detection >0.99 was observed, with Rayliegh mean localization error of 1.65 mm. The study establishes the feasibility of a robust experimental model and deep learning solution for UWB microwave stroke detection.

  View details for DOI 10.1088/0031-9155/41/11/001

  View details for PubMedID 37873017

  View details for PubMedCentralID PMC10593075

• Continued Infarction Growth and Penumbral Consumption After Reperfusion in Vaccine-Naive Patients With COVID-19: A Case- Control Study AMERICAN JOURNAL OF ROENTGENOLOGY Dehkharghani, S., Vogel, A., Jandhyala, N., Chung, C., Shu, L., Frontera, J., Yaghi, S. 2023; 221 (4): 517-525

  Abstract

  BACKGROUND. Neurologic sequelae of SARS-CoV-2 include potentially malignant cerebrovascular events arising from complex hemodynamic, hematologic, and inflammatory processes occurring in concert. OBJECTIVE. This study concerns the hypothesis that despite angiographic reperfusion COVID-19 promotes continued consumption of at-risk tissue volumes after acute ischemic stroke (AIS), yielding critical insights into prognostication and monitoring paradigms in vaccine-naive patients experiencing AIS. METHODS. This retrospective study compared 100 consecutive COVID-19 patients with AIS presenting between March 2020 and April 2021 with a contemporaneous cohort of 282 AIS patients without COVID-19. Reperfusion classes were dichotomized into positive (extended thrombolysis in cerebral ischemia [eTICI] score = 2c-3) and negative (eTICI score < 2c) groups. All patients underwent endovascular therapy after initial CT perfusion imaging (CTP) to document infarction core and total hypoperfusion volumes. RESULTS. Ten COVID-positive (mean age ± SD, 67 ± 12 years; seven men, three women) and 144 COVID-negative patients (mean age, 71 ± 16 years; 76 men, 68 women) undergoing endovascular reperfusion, with antecedent CTP and follow-up imaging, comprised the final dataset. Initial infarction core and total hypoperfusion volumes (mean ± SD) were 1.5 ± 18 mL and 85 ± 100 mL in COVID-negative patients and 30.5 ± 34 mL and 117 ± 80.5 mL in COVID-positive patients, respectively. Final infarction volumes were significantly larger in patients with COVID-19, with median volumes of 77.8 mL versus 18.2 mL among control patients (p = .01), as were normalized measures of infarction growth relative to baseline infarction volume (p = .05). In adjusted logistic parametric regression models, COVID positivity emerged as a significant predictor for continued infarct growth (OR, 5.10 [95% CI, 1.00-25.95]; p = .05). CONCLUSION. These findings support the potentially aggressive clinical course of cerebrovascular events in patients with COVID-19, suggesting greater infarction growth and ongoing consumption of at-risk tissues, even after angiographic reperfusion. CLINICAL IMPACT. SARS-CoV-2 infection may promote continued infarction progression despite angiographic reperfusion in vaccine-naive patients with large-vessel occlusion AIS. The findings carry potential implications for prognostication, treatment selection, and surveillance for infarction growth among revascularized patients in future waves of infection by novel viral strains.

  View details for DOI 10.2214/AJR.23.29296

  View details for Web of Science ID 001075855700019

  View details for PubMedID 37195793

• Development and Validation of a Postprocedural Model to Predict Outcome After Endovascular Treatment for Ischemic Stroke. JAMA neurology Chalos, V., Venema, E., Mulder, M. J., Roozenbeek, B., Steyerberg, E. W., Wermer, M. J., Lycklama À Nijeholt, G. J., van der Worp, H. B., Goyal, M., Campbell, B. C., Muir, K. W., Guillemin, F., Bracard, S., White, P., Dávalos, A., Jovin, T. G., Hill, M. D., Mitchell, P. J., Demchuk, A. M., Saver, J. L., van der Lugt, A., Brown, S., Dippel, D. W., Lingsma, H. F. 2023; 80 (9): 940-8

  Abstract

  Outcome prediction after endovascular treatment (EVT) for ischemic stroke is important to patients, family members, and physicians.To develop and validate a model based on preprocedural and postprocedural characteristics to predict functional outcome for individual patients after EVT.A prediction model was developed using individual patient data from 7 randomized clinical trials, performed between December 2010 and December 2014. The model was developed within the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) collaboration and external validation in data from the Dutch Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry of patients treated in clinical practice between March 2014 and November 2017. Participants included patients from multiple centers throughout different countries in Europe, North America, East Asia, and Oceania (derivation cohort), and multiple centers in the Netherlands (validation cohort). Included were adult patients with a history of ischemic stroke from an intracranial large vessel occlusion in the anterior circulation who underwent EVT within 12 hours of symptom onset or last seen well. Data were last analyzed in July 2022.A total of 19 variables were assessed by multivariable ordinal regression to predict functional outcome (modified Rankin Scale [mRS] score) 90 days after EVT. Variables were routinely available 1 day after EVT. Akaike information criterion (AIC) was used to optimize model fit vs model complexity. Probabilities for functional independence (mRS 0-2) and survival (mRS 0-5) were derived from the ordinal model. Model performance was expressed with discrimination (C statistic) and calibration.A total of 781 patients (median [IQR] age, 67 [57-76] years; 414 men [53%]) constituted the derivation cohort, and 3260 patients (median [IQR] age, 72 [61-80] years; 1684 men [52%]) composed the validation cohort. Nine variables were included in the model: age, baseline National Institutes of Health Stroke Scale (NIHSS) score, prestroke mRS score, history of diabetes, occlusion location, collateral score, reperfusion grade, NIHSS score at 24 hours, and symptomatic intracranial hemorrhage 24 hours after EVT. External validation in the MR CLEAN Registry showed excellent discriminative ability for functional independence (C statistic, 0.91; 95% CI, 0.90-0.92) and survival (0.89; 95% CI, 0.88-0.90). The proportion of functional independence in the MR CLEAN Registry was systematically higher than predicted by the model (41% vs 34%), whereas observed and predicted survival were similar (72% vs 75%). The model was updated and implemented for clinical use.The prognostic tool MR PREDICTS@24H can be applied 1 day after EVT to accurately predict functional outcome for individual patients at 90 days and to provide reliable outcome expectations and personalize follow-up and rehabilitation plans. It will need further validation and updating for contemporary patients.

  View details for DOI 10.1001/jamaneurol.2023.2392

  View details for PubMedID 37523199

  View details for PubMedCentralID PMC10391355

• White Matter Cerebrovascular Reactivity: Effects of Microangiopathy and Proximal Occlusions on the Dynamic BOLD Response. medRxiv : the preprint server for health sciences Gee, J. M., Wang, X., Dogra, S., Veraart, J., Ishida, K., Dehkharghani, S. 2023

  Abstract

  Cerebral microangiopathy often manifests as white matter hyperintensities (WMH) on T2-weighted MR images and is associated with elevated stroke risk. Large vessel steno-occlusive disease (SOD) is also independently associated with stroke risk, however, the interaction of microangiopathy and SOD is not well understood. Cerebrovascular reactivity (CVR) describes the capacity of cerebral circulation to adapt to changes in perfusion pressure and neurovascular demand, and its impairment portends future infarctions. CVR can be measured with blood oxygen level dependent (BOLD) imaging following acetazolamide stimulus (ACZ-BOLD). We studied CVR differences between WMH and normal-appearing white matter (NAWM) in patients with chronic SOD, hypothesizing additive influences upon CVR measured by novel, fully dynamic CVR maxima ( CVR max ).A cross sectional study was conducted to measure per-voxel, per-TR maximal CVR ( CVR max ) using a custom computational pipeline in 23 subjects with angiographically-proven unilateral SOD. WMH and NAWM masks were applied to CVR max maps. White matter was subclassified with respect to the SOD-affected hemisphere, including: i. contralateral NAWM; ii. contralateral WMH iii. ipsilateral NAWM; iv. ipsilateral WMH. CVR max was compared between these groups with a Kruskal-Wallis test followed by a Dunn-Sidak post-hoc test for multiple comparisons.19 subjects (age 50±12 years, 53% female) undergoing 25 examinations met criteria. WMH volume was asymmetric in 16/19 subjects with 13/16 exhibiting higher volumes ipsilateral to SOD. Pairwise comparisons of CVR max between groups was significant with ipsilateral WMH CVR max lower than contralateral NAWM (p=0.015) and contralateral WMH (p=0.003) when comparing in-subject medians and lower than all groups when comparing pooled voxelwise values across all subjects (p<0.0001). No significant relationship between WMH lesion size and CVR max was detected.Our results suggest additive effects of microvascular and macrovascular disease upon white matter CVR, but with greater overall effects relating to macrovascular SOD than to apparent microangiopathy. Dynamic ACZ-BOLD presents a promising path towards a quantitative stroke risk imaging biomarker.Cerebral white matter (WM) microangiopathy manifests as sporadic or sometimes confluent high intensity lesions in MR imaging with T2-weighting, and bears known associations with stroke, cognitive disability, depression and other neurological disorders 1-5 . Deep white matter is particularly susceptible to ischemic injury owing to the deprivation of collateral flow between penetrating arterial territories, and hence deep white matter hyperintensities (WMH) may portend future infarctions 6-8 . The pathophysiology of WMH is variable but commonly includes a cascade of microvascular lipohyalinosis and atherosclerosis together with impaired vascular endothelial and neurogliovascular integrity, leading to blood brain barrier dysfunction, interstitial fluid accumulation, and eventually tissue damage 9-14 . Independent of the microcirculation, cervical and intracranial large vessel steno-occlusive disease (SOD) often results from atheromatous disease and is associated with increased risk of stroke owing to thromboembolic phenomena, hypoperfusion, or combinations thereof 15-17 . White matter disease is more common in the affected hemisphere of patients with asymmetric or unilateral SOD, producing both macroscopic WMH detectable by routine structural MRI, as well as microstructural changes and altered structural connectivity detected by advanced diffusion microstructural imaging 18, 19 . An improved understanding of the interaction of microvascular disease (i.e., WMH) and macrovascular steno-occlusion could better inform stroke risk stratification and guide treatment strategies when coexistent. Cerebrovascular reactivity (CVR) is an autoregulatory adaptation characterized by the capacity of the cerebral circulation to respond to physiological or pharmacological vasodilatory stimuli 20-22 . CVR may be heterogeneous and varies across tissue type and pathological states 1, 16 . Alterations in CVR are associated with elevated stroke risk in SOD patients, although white matter CVR, and in particular the CVR profiles of WMH, are only sparsely studied and not fully understood 1, 23-26 . We have previously employed blood oxygen level dependent (BOLD) imaging following a hemodynamic stimulus with acetazolamide (ACZ) in order to measure CVR (i.e. ACZ-BOLD) 21, 27, 28 . Despite the emergence of ACZ-BOLD as a technique for clinical and experimental use, poor signal-to-noise characteristics of the BOLD effect have generally limited its interpretation to coarse, time-averaged assessment of the terminal ACZ response at arbitrarily prescribed delays following ACZ administration (e.g. 10-20 minutes) 29 . More recently, we have introduced a dedicated computational pipeline to overcome historically intractable signal-to-noise ratio (SNR) limitations of BOLD, enabling fully dynamic characterization of the cerebrovascular response, including identification of previously unreported, unsustained or transient CVR maxima ( CVR max ) following hemodynamic provocation 27, 30 . In this study, we compared such dynamic interrogation of true CVR maxima between WMH and normal appearing white matter (NAWM) among patients with chronic, unilateral SOD in order to quantify their interaction and to assess the hypothesized additive effects of angiographically-evident macrovascular stenoses when intersecting microangiopathic WMH.

  View details for DOI 10.1101/2023.05.29.23290700

  View details for PubMedID 37398412

  View details for PubMedCentralID PMC10312885

• Autonomous animal heating and cooling system for temperature-regulated MR experiments. ArXiv Verghese, G., Voroslakos, M., Markovic, S., Tal, A., Dehkharghani, S., Yaghmazadeh, O., Alon, L. 2023

  Abstract

  Temperature is a hallmark parameter influencing almost all magnetic resonance properties (e.g., T\textsubscript{1}, T\textsubscript{2}, proton density, diffusion and more). In the pre-clinical setting, temperature has a large influence on animal physiology (e.g., respiration rate, heart rate, metabolism, cellular stress, and more) and needs to be carefully regulated, especially when the animal is under anesthesia and thermoregulation is disrupted. We present an open-source heating and cooling system capable of stabilizing the temperature of the animal. The system was designed using Peltier modules capable of heating or cooling a circulating water bath with active temperature feedback. Feedback was obtained using a commercial thermistor, placed in the animal rectum, and a proportional{\text -}integral{\text -}derivative (PID) controller capable of locking the temperature. Operation was demonstrated in a phantom as well as mouse and rat animal models, where the standard deviation of the temperature of the animal upon convergence was less than a tenth of a degree. An application where brain temperature of a mouse was modulated was demonstrated using an invasive optical probe and non-invasive magnetic resonance spectroscopic thermometry measurements.

  View details for PubMedID 37205261

  View details for PubMedCentralID PMC10187369

• Imaging Factors Associated With Poor Outcome in Patients With Basilar Artery Occlusion Treated With Endovascular Thrombectomy STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY Heit, J. J., Mlynash, M., Cereda, C. W., Yuen, N., Lansberg, M. G., Bianco, G., Christensen, S., Qureshi, A. Y., Hinduja, A., Dehkharghani, S., Goldman-Yassen, A. E., Hsieh, K., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T. D., Fiehler, J., Pileggi, M., Campbell, B., Albers, G. W. 2023; 3 (3)

  View details for DOI 10.1161/SVIN.122.000767

  View details for Web of Science ID 001162312700023

• Acetazolamide-augmented BOLD MRI to Assess Whole-Brain Cerebrovascular Reactivity in Chronic Steno-occlusive Disease Using Principal Component Analysis RADIOLOGY Dogra, S., Wang, X., Gupta, A., Veraart, J., Ishida, K., Qiu, D., Dehkharghani, S. 2023; 307 (3): e221473

  Abstract

  Background Exhaustion of cerebrovascular reactivity (CVR) portends increased stroke risk. Acetazolamide-augmented blood oxygenation level-dependent (BOLD) MRI has been used to estimate CVR, but low signal-to-noise conditions relegate its use to terminal CVR (CVRend) measurements that neglect dynamic features of CVR. Purpose To demonstrate comprehensive characterization of acetazolamide-augmented BOLD MRI response in chronic steno-occlusive disease using a computational framework to precondition signal time courses for dynamic whole-brain CVR analysis. Materials and Methods This study focused on retrospective analysis of consecutive patients with unilateral chronic steno-occlusive disease who underwent acetazolamide-augmented BOLD imaging for recurrent minor stroke or transient ischemic attack at an academic medical center between May 2017 and October 2020. A custom principal component analysis-based denoising pipeline was used to correct spatially varying non-signal-bearing contributions obtained by a local principal component analysis of the MRI time series. Standard voxelwise CVRend maps representing terminal responses were produced and compared with maximal CVR (CVRmax) as isolated from binned (per-repetition time) denoised BOLD time course. A linear mixed-effects model was used to compare CVRmax and CVRend in healthy and diseased hemispheres. Results A total of 23 patients (median age, 51 years; IQR, 42-61, 13 men) who underwent 32 BOLD examinations were included. Processed MRI data showed twofold improvement in signal-to-noise ratio, allowing improved isolation of dynamic characteristics in signal time course for sliding window CVRmax analysis to the level of each BOLD repetition time (approximately 2 seconds). Mean CVRmax was significantly higher than mean CVRend in diseased (5.2% vs 3.8%, P < .01) and healthy (5.5% vs 4.0%, P < .01) hemispheres. Several distinct time-signal signatures were observed, including nonresponsive; delayed/blunted; brisk; and occasionally nonmonotonic time courses with paradoxical features in normal and abnormal tissues (ie, steal and reverse-steal patterns). Conclusion A principal component analysis-based computational framework for analysis of acetazolamide-augmented BOLD imaging can be used to measure unsustained CVRmax through twofold improvements in signal-to-noise ratio. © RSNA, 2023 Supplemental material is available for this article.

  View details for DOI 10.1148/radiol.221473

  View details for Web of Science ID 001001897600009

  View details for PubMedID 36916889

  View details for PubMedCentralID PMC10140639

• Imaging Factors Associated With Poor Outcome in Patients With Basilar Artery Occlusion Treated With Endovascular Thrombectomy. Stroke (Hoboken, N.J.) Heit, J. J., Mlynash, M., Cereda, C. W., Yuen, N., Lansberg, M. G., Bianco, G., Christensen, S., Qureshi, A. Y., Hinduja, A., Dehkharghani, S., Goldman-Yassen, A. E., Hsieh, K. L., Giurgiutiu, D. V., Gibson, D., Carrera, E., Alemseged, F., Faizy, T. D., Fiehler, J., Pileggi, M., Campbell, B., Albers, G. W. 2023; 3 (3): e000767

  Abstract

  Acute ischemic stroke attributed to basilar artery occlusion (BAO) results in high rates of death and significant morbidity. Endovascular thrombectomy an effective treatment for BAO, but imaging parameters that predict a favorable response to thrombectomy are not well defined. We determined which imaging parameters were associated with poor outcome in patients with BAO treated by thrombectomy.We performed a retrospective cohort study of patients with BAO who underwent thrombectomy at multiple international stroke centers. All patients underwent computed tomography or magnetic resonance perfusion imaging before treatment. Clinical and imaging variables were measured and correlated to poor functional outcomes (modified Rankin scale score ≥4) after thrombectomy. Imaging variables included the following: Critical Area Perfusion Score, Posterior Circulation Alberta Stroke Program Early Computed Tomography Score, ischemic core volume (30% cerebral blood flow on computed tomography perfusion or diffusion-weighted imaging), and volume of time to maximum >10 seconds. Clinical and imaging variables associated with poor functional outcome were assessed by a multivariable binary logistic regression analysis.A total of 102 patients were included in the study. Median patient age was 66.5 years (interquartile range [IQR], 55-78), median presentation National Institutes of Health Stroke Scale score was 14 (IQR, 7-23), and the median time from last seen normal was 4 hours (IQR, 1:52-9:20). Patient age (odds ratio [OR], 1.37 per 5-year increment [95% CI, 1.08-1.72]; P=0.008), presentation National Institutes of Health Stroke Scale score (OR, 1.11 [95% CI, 1.04-1.18]; P=0.001), successful reperfusion after thrombectomy (OR, 0.03 [95% CI, 0.003-0.25]; P=0.002), Posterior Circulation Alberta Stroke Program Early Computed Tomography Score ≤6 (OR, 11.40 [95% CI, 1.73-75]; P=0.011), and Critical Area Perfusion Score >3 (OR, 26.22 [95% CI, 1.07-642]; P=0.045) independently predicted poor outcome after BAO thrombectomy. Ischemic core volume (30% cerebral blood flow) and volume of time to maximum >10 seconds did not predict poor outcome.Age, National Institutes of Health Stroke Scale presentation, unsuccessful reperfusion, Critical Area Perfusion Score >3, and Posterior Circulation Alberta Stroke Program Early Computed Tomography Score ≤6 are independently associated with poor outcome after BAO thrombectomy.

  View details for DOI 10.1161/SVIN.122.000767

  View details for PubMedID 41584979

  View details for PubMedCentralID PMC12778642

• Diaschisis Profiles in the Cerebellar Response to Hemodynamic Stimuli: Insights From Dynamic Measurement of Cerebrovascular Reactivity to Identify Occult and Transient Maxima JOURNAL OF MAGNETIC RESONANCE IMAGING Dogra, S., Wang, X., Gee, J., Gupta, A., Veraart, J., Ishida, K., Qiu, D., Dehkharghani, S. 2023; 58 (5): 1462-1469

  Abstract

  Crossed cerebellar diaschisis (CCD) refers to depressions in perfusion and metabolism within the cerebellar hemisphere contralateral to supratentorial disease. Prior investigation into CCD in cerebrovascular reactivity (CVR) has been limited to terminal CVR estimations (CVRend ). We recently have demonstrated the presence of unsustained CVR maxima (CVRmax ) using dynamic CVR analysis, offering a fully dynamic characterization of CVR to hemodynamic stimuli.To investigate CCD in CVRmax from dynamic blood oxygen level-dependent (BOLD) MRI, by comparison with conventional CVRend estimation.Retrospective.A total of 23 patients (median age: 51 years, 10 females) with unilateral chronic steno-occlusive cerebrovascular disease, without prior knowledge of CCD status.A 3-T, T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and acetazolamide-augmented BOLD imaging performed with a gradient-echo echo-planar imaging (EPI) sequence.A custom denoising pipeline was used to generate BOLD-CVR time signals. CVRend was established using the last minute of the BOLD response relative to the first-minute baseline. Following classification of healthy versus diseased cerebral hemispheres, CVRmax and CVRend were calculated for bilateral cerebral and cerebellar hemispheres. Three independent observers evaluated all data for the presence of CCD.Pearson correlations for comparing CVR across hemispheres, two-proportion Z-tests for comparing CCD prevalence, and Wilcoxon signed-rank tests for comparing median CVR. The level of statistical significance was set at P ≤ 0.05.CCD-related changes were observed on both CVRend and CVRmax maps, with all CCD+ cases identifiable by inspection of either map. Diseased cerebral and contralateral cerebellar hemispheric CVR correlations in CCD+ patients were stronger when using CVRend (r = 0.728) as compared to CVRmax (r = 0.676). CVR correlations between healthy cerebral hemispheres and contralateral cerebellar hemispheres were stronger for CVRmax (r = 0.739) than for CVRend (r = 0.705).CCD-related alterations could be observed in CVR examinations. Conventional CVRend may underestimate CVR and could exaggerate CCD.4.Stage 3.

  View details for DOI 10.1002/jmri.28648

  View details for Web of Science ID 000962168700001

  View details for PubMedID 36995159

• Diaschisis Profiles In The Hemodynamic Response To Hemodynamic Stimuli: Implications For Cerebellar Normalization In Patients With Steno-occlusive Disease Dogra, S., Wang, X., Gee, J. M., Gupta, A., Veraart, J., Ishida, K., Qiu, D., Dehkharghani, S. LIPPINCOTT WILLIAMS & WILKINS. 2023

  View details for DOI 10.1161/str.54.suppl_1.137

  View details for Web of Science ID 000992453800135

• Eliminating False Positive Detections Of Intracranial Hemorrhage (ICH) Using RAPID ICH 3 Sreekrishnan, A., Giurgiutiu, D., Kitamura, F., Martinelli, C., Haerian, H., Dehkharghani, S., Heit, J. J. LIPPINCOTT WILLIAMS & WILKINS. 2023

  View details for DOI 10.1161/str.54.suppl_1.WMP60

  View details for Web of Science ID 000992453800623

• Replicability of proton MR spectroscopic imaging findings in mild traumatic brain injury: Implications for clinical applications NEUROIMAGE-CLINICAL Chen, A. M., Gerhalter, T., Dehkharghani, S., Peralta, R., Gajdosik, M., Gajdosik, M., Tordjman, M., Zabludovsky, J., Sheriff, S., Ahn, S., Babb, J. S., Bushnik, T., Zarate, A., Silver, J. M., Im, B. S., Wall, S. P., Madelin, G., Kirov, I. I. 2023; 37

  View details for DOI 10.1016/j.nicl.2023.103325

  View details for Web of Science ID 000974629500001

• Phosphorus metabolism in the brain of cognitively normal midlife individuals at risk for Alzheimer's disease. Neuroimage. Reports Parasoglou, P., Osorio, R. S., Khegai, O., Kovbasyuk, Z., Miller, M., Ho, A., Dehkharghani, S., Wisniewski, T., Convit, A., Mosconi, L., Brown, R. 2022; 2 (4)

  Abstract

  Background: Neurometabolic abnormalities and amyloid-beta plaque deposition are important early pathophysiologic changes in Alzheimer's disease (AD). This study investigated the relationship between high-energy phosphorus-containing metabolites, glucose uptake, and amyloid plaque using phosphorus magnetic resonance spectroscopy (31P-MRS) and positron emission tomography (PET).Methods: We measured 31P-MRS, fluorodeoxyglucose (FDG)-PET, and Pittsburgh Compound B (PiB)-PET in a cohort of 20 cognitively normal middle-aged adults at risk for AD. We assessed 31P-MRS reliability by scanning a separate cohort of 13 healthy volunteers twice each. We calculated the coefficient-of-variation (CV) of metabolite ratios phosphocreatine-to-adenosine triphosphate (PCr/alpha-ATP), inorganic phosphate (Pi)-to-alpha-ATP, and phosphomonoesters-to-phosphodiesters (PME/PDE), and pH in pre-defined brain regions. We performed linear regression analysis to determine the relationship between 31P measurements and tracer uptake, and Dunn's multiple comparison tests to investigate regional differences in phosphorus metabolism. Finally, we performed linear regression analysis on 31P-MRS measurements in both cohorts to investigate the relationship of phosphorus metabolism with age.Results: Most regional 31P metabolite ratio and pH inter- and intra-day CVs were well below 10%. There was an inverse relationship between FDG-SUV levels and metabolite ratios PCr/alpha-ATP, Pi/alpha-ATP, and PME/PDE in several brain regions in the AD risk group. There were also several regional differences among 31P metabolites and pH in the AD risk group including elevated PCr/alpha-ATP, depressed PME/PDE, and elevated pH in the temporal cortices. Increased PCr/alpha-ATP throughout the brain was associated with aging.Conclusions: Phosphorus spectroscopy in the brain can be performed with high repeatability. Phosphorus metabolism varies with region and age, and is related to glucose uptake in adults at risk for AD. Phosphorus spectroscopy may be a valuable approach to study early changes in brain energetics in high-risk populations.

  View details for DOI 10.1016/j.ynirp.2022.100121

  View details for PubMedID 36532654

• Highly time-resolved 4D MR angiography using golden-angle radial sparse parallel (GRASP) MRI SCIENTIFIC REPORTS Goldman-Yassen, A. E., Raz, E., Borja, M. J., Chen, D., Derman, A., Dogra, S., Block, K., Dehkharghani, S. 2022; 12 (1): 15099

  Abstract

  Current dynamic MRA techniques are limited by temporal resolution and signal-to-noise penalties. GRASP, a fast and flexible MRI technique combining compressed-sensing, parallel imaging, and golden-angle radial sampling, acquires volumetric data continuously and can be reconstructed post hoc for user-defined applications. We describe a custom pipeline to retrospectively reconstruct ultrahigh temporal resolution, dynamic MRA from GRASP imaging obtained in the course of routine practice. GRASP scans were reconstructed using a custom implementation of the GRASP algorithm and post-processed with MeVisLab (MeVis Medical Solutions AG, Germany). Twenty consecutive examinations were scored by three neuroradiologists for angiographic quality of specific vascular segments and imaging artifacts using a 4-point scale. Unsubtracted images, baseline-subtracted images, and a temporal gradient dataset were available in 2D and 3D reconstructions. Distinct arterial and capillary phases were identified in all reconstructions, with a median of 2 frames (IQR1-3 and 2-3, respectively). Median rating for vascular segments was 3 (excellent) in all reconstructions and for nearly all segments, with excellent intraclass correlation (range 0.91-1.00). No cases were degraded by artifacts. GRASP-MRI obtained in routine practice can be seamlessly repurposed to produce high quality 4D MRA with 1-2-s resolved isotropic cerebrovascular angiography. Further exploration into diagnostic accuracy in disease-specific applications is warranted.

  View details for DOI 10.1038/s41598-022-18191-y

  View details for Web of Science ID 000850287900029

  View details for PubMedID 36064872

  View details for PubMedCentralID PMC9445093

• Alterations in Functional Network Topology Within Normal Hemispheres Contralateral to Anterior Circulation Steno-Occlusive Disease: A Resting-State BOLD Study FRONTIERS IN NEUROLOGY Wu, J., Nahab, F., Allen, J. W., Hu, R., Dehkharghani, S., Qiu, D. 2022; 13: 780896

  Abstract

  The purpose of this study was to assess spatially remote effects of hemodynamic impairment on functional network topology contralateral to unilateral anterior circulation steno-occlusive disease (SOD) using resting-state blood oxygen level-dependent (BOLD) imaging, and to investigate the relationships between network connectivity and cerebrovascular reactivity (CVR), a measure of hemodynamic stress. Twenty patients with unilateral, chronic anterior circulation SOD and 20 age-matched healthy controls underwent resting-state BOLD imaging. Five-minute standardized baseline BOLD acquisition was followed by acetazolamide infusion to measure CVR. The BOLD baseline was used to analyze network connectivity contralateral to the diseased hemispheres of SOD patients. Compared to healthy controls, reduced network degree (z-score = -1.158 ± 1.217, P < 0.001, false discovery rate (FDR) corrected), local efficiency (z-score = -1.213 ± 1.120, P < 0.001, FDR corrected), global efficiency (z-score = -1.346 ± 1.119, P < 0.001, FDR corrected), and enhanced modularity (z-score = 1.000 ± 1.205, P = 0.002, FDR corrected) were observed in the contralateral, normal hemispheres of SOD patients. Network degree (P = 0.089, FDR corrected; P = 0.027, uncorrected) and nodal efficiency (P = 0.089, FDR corrected; P = 0.045, uncorrected) showed a trend toward a positive association with CVR. The results indicate remote abnormalities in functional connectivity contralateral to the diseased hemispheres in patients with unilateral SOD, despite the absence of macrovascular disease or demonstrable hemodynamic impairment. The clinical impact of remote functional disruptions requires dedicated investigation but may portend far reaching consequence for even putatively unilateral cerebrovascular disease.

  View details for DOI 10.3389/fneur.2022.780896

  View details for Web of Science ID 000780199500001

  View details for PubMedID 35392638

  View details for PubMedCentralID PMC8980268

• Clinical outcome of patients with mild pre-stroke morbidity following endovascular treatment: a HERMES substudy JOURNAL OF NEUROINTERVENTIONAL SURGERY McDonough, R., Ospel, J. M., Majoie, C. M., Saver, J. L., White, P., Dippel, D. W. J., Brown, S. B., Demchuk, A. M., Jovin, T. G., Mitchell, P. J., Bracard, S., Campbell, B. C., Muir, K. W., Hill, M. D., Guillemin, F., Goyal, M., HERMES Collaborators 2023; 15 (3): 214-+

  Abstract

  Analyses of the effect of pre-stroke functional levels on the outcome of endovascular therapy (EVT) have focused on the course of patients with moderate to substantial pre-stroke disability. The effect of complete freedom from pre-existing disability (modified Rankin Scale (mRS) 0) versus predominantly mild pre-existing disability/symptoms (mRS 1-2) has not been well delineated.The HERMES meta-analysis pooled data from seven randomized trials that tested the efficacy of EVT. We tested for a multiplicative interaction effect of pre-stroke mRS on the relationship between treatment and outcomes. Ordinal regression was used to assess the association between EVT and 90-day mRS (primary outcome) in the subgroup of patients with pre-stroke mRS 1-2. Multivariable regression modeling was then used to test the effect of mild pre-stroke disability/symptoms on the primary and secondary outcomes (delta-mRS, mRS 0-2/5-6) compared with patients with pre-stroke mRS 0.We included 1764 patients, of whom 199 (11.3%) had pre-stroke mRS 1-2. No interaction effect of pre-stroke mRS on the relationship between treatment and outcome was observed. Patients with pre-stroke mRS 1-2 had worse outcomes than those with pre-stroke mRS 0 (adjusted common OR (acOR) 0.53, 95% CI 0.40 to 0.70). Nonetheless, a significant benefit of EVT was observed within the mRS 1-2 subgroup (cOR 2.08, 95% CI 1.22 to 3.55).Patients asymptomatic/without disability prior to onset have better outcomes following EVT than patients with mild disability/symptoms. Patients with pre-stroke mRS 1-2, however, more often achieve good outcomes with EVT compared with conservative management. These findings indicate that mild pre-existing disability/symptoms influence patient prognosis after EVT but do not diminish the EVT treatment effect.

  View details for DOI 10.1136/neurintsurg-2021-018428

  View details for Web of Science ID 000782136300001

  View details for PubMedID 35210331

• Cerebral Perfusion Imaging And Posterior Circulation ASPECTS Identify Stroke Patients Who Benefit From Basilar Artery Thrombectomy Heit, J. J., Bianco, G., Mlynash, M., Yuen, N., Qureshi, A. Y., Hinduja, A., Dehkharghani, S., Goldman-Yassen, A., Hsieh, K., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T. D., Fiehler, J., Pileggi, M., Lansberg, M. G., Campbell, B., Albers, G. W., Cereda, C. W. LIPPINCOTT WILLIAMS & WILKINS. 2022

  View details for DOI 10.1161/str.53.suppl_1.126

  View details for Web of Science ID 000788100600123

• Hemorrhagic Conversion Of Ischemic Stroke Is Associated With Hematoma Expansion Palaychuk, N., Changa, A., Dogra, S., Wei, J., Lewis, A., Lord, A., Ishida, K., Zhang, C., Czeisler, B. M., Torres, J. L., Frontera, J., Dehkharghani, S., Melmed, K. R. LIPPINCOTT WILLIAMS & WILKINS. 2022

  View details for DOI 10.1161/str.53.suppl_1.TP99

  View details for Web of Science ID 000788100600385

• Radial spoiled gradient T1 weighted imaging of the internal auditory canal: Is Scarpa's ganglion now an expected finding and source of fundal enhancement? NEURORADIOLOGY JOURNAL Munawar, K., Raz, E., Dehkharghani, S., Fatterpekar, G. M., Block, T. K., Lui, Y. W. 2022; 35 (5): 563-565

  Abstract

  StarVIBE is a 3D gradient-echo sequence with a radial, stack-of-stars acquisition having spatial resolution and tissue contrast. With newer sequences, it is important to be familiar with sequence tissue contrasts and appearance of anatomical variants. We evaluated 450 patients utilizing this sequence; 35 patients demonstrated fluffy "cotton wool" enhancement at the internal auditory canal fundus without clear pathology. We favor this represents anatomic neurovascular enhancement that StarVIBE is sensitive to and is a touch-me-not finding.

  View details for DOI 10.1177/19714009211067407

  View details for Web of Science ID 000748525600001

  View details for PubMedID 35015577

  View details for PubMedCentralID PMC9513923

• Vessel wall imaging with advanced flow suppression in the characterization of intracranial aneurysms following flow diversion with Pipeline embolization device JOURNAL OF NEUROINTERVENTIONAL SURGERY Raz, E., Goldman-Yassen, A., Derman, A., Derakhshani, A., Grinstead, J., Dehkharghani, S. 2022; 14 (12): 1264-1269

  Abstract

  High-resolution vessel wall MRI (VWI) is increasingly used to characterize intramural disorders of the intracranial vasculature unseen by conventional arteriography.To evaluate the use of VWI for surveillance of flow diverter (FD) treated aneurysms.Retrospective study of 28 aneurysms (in 21 patients) treated with a FD (mean 57 years; 14 female). All examinations included VWI and a contemporaneously obtained digital subtraction angiogram. Multiplanar pre- and post-gadolinium 3D, variable flip-angle T1 black-blood VWI was obtained using delay alternating nutation for tailored excitation (DANTE) at 3T. 3D time-of-flight MR angiography (MRA) was also carried out. Images were assessed for in-stent stenosis, aneurysm occlusion, presence and pattern/distribution of aneurysmal or parent vessel gadolinium enhancement.The VWI-MRI was performed on average at 361±259 days after the intervention. Follow-up DSA was performed at 338±254 days postintervention. Good or excellent black-blood angiographic quality was recorded in 22/28 (79%) pre-contrast and 21/28 (75%) post-contrast VWI, with no cases excluded for image quality. Aneurysm enhancement was noted in 24/28 (85.7%) aneurysms, including in 79% of angiographically occluded aneurysms and 100% of angiographically non-occluded aneurysms. Enhancement of the stented parent-vessel wall occurred significantly more often when aneurysm enhancement was present (92% vs 33%, p=0.049).Advanced VWI produces excellent depiction of FD-treated aneurysms, with robust evaluation of the parent vessel and aneurysm wall to an extent not achievable with conventional MRI/MRA. Gadolinium enhancement may, however, continue even after enduring catheter angiographic occlusion, confounding interpretation, and requiring cognizance of this potentially prolonged effect in such patients.

  View details for DOI 10.1136/neurintsurg-2021-018086

  View details for Web of Science ID 000740753100001

  View details for PubMedID 34987073

• Diagnostic Performance of Computed Tomography Angiography and Computed Tomography Perfusion Tissue Time-to-Maximum in Vasospasm Following Aneurysmal Subarachnoid Hemorrhage JOURNAL OF THE AMERICAN HEART ASSOCIATION Allen, J. W., Prater, A., Kallas, O., Abidi, S. A., Howard, B. M., Tong, F., Agarwal, S., Yaghi, S., Dehkharghani, S. 2022; 11 (1): e023828

  Abstract

  Background Vasospasm is a treatable cause of deterioration following aneurysmal subarachnoid hemorrhage. Cerebral computed tomography perfusion mean transit times have been proposed as a predictor of vasospasm but suffer from well-known technical limitations. We evaluated fully automated, thresholded time-to-maxima of the tissue residue function (Tmax) for determination of vasospasm following aneurysmal subarachnoid hemorrhage. Methods and Results Retrospective analysis of 540 arterial segments from 36 encounters in 31 consecutive patients with aneurysmal subarachnoid hemorrhage undergoing computed tomography angiography (CTA), computed tomography perfusion, and digital subtraction angiography (DSA) within 24 hours. Tmax at 4, 6, 8, and 10 s was generated using RAPID (iSchemaView Inc., Menlo Park, CA). Dual-reader CTA and computed tomography perfusion interpretations were compared for patients with and without vasospasm on DSA (DSA+ and DSA-). Logistic regression models were developed using CTA and Tmax as input predictors and DSA vasospasm as outcome in adjusted and unadjusted models. Imaging studies from all 31 subjects (mean age 47.3±11.1, 77% female, 65% with single aneurysm with mean size of 6.0±2.9 mm) were included. Vasospasm was identified in 42 segments on DSA and 59 segments on CTA, with significant associations across individual vessel segments (P<0.001). In adjusted analyses, DSA vasospasm was associated with CTA (odds ratio [OR], 2.43; 95% CI, 0.94-6.32; P=0.068) as well as territory-specific Tmax>6 seconds delays (OR, 3.57; 95% CI, 1.36-9.35; P=0.009). Sensitivity/specificity for DSA vasospasm was 31%/91% for CTA, 26%/89% for Tmax>6 seconds, and 12%/99% for CTA+Tmax>6 seconds. Conclusions CTA and Tmax offer high specificity for presence of vasospasm; their utility, even in combination, as screening tests is, however, limited by poor sensitivity.

  View details for DOI 10.1161/JAHA.121.023828

  View details for Web of Science ID 000739838600016

  View details for PubMedID 34970916

  View details for PubMedCentralID PMC9075209

• A stroke detection and discrimination framework using broadband microwave scattering on stochastic models with deep learning SCIENTIFIC REPORTS Alon, L., Dehkharghani, S. 2021; 11 (1): 24222

  Abstract

  Stroke poses an immense public health burden and remains among the primary causes of death and disability worldwide. Emergent therapy is often precluded by late or indeterminate times of onset before initial clinical presentation. Rapid, mobile, safe and low-cost stroke detection technology remains a deeply unmet clinical need. Past studies have explored the use of microwave and other small form-factor strategies for rapid stroke detection; however, widespread clinical adoption remains unrealized. Here, we investigated the use of microwave scattering perturbations from ultra wide-band antenna arrays to learn dielectric signatures of disease. Two deep neural networks (DNNs) were used for: (1) stroke detection ("classification network"), and (2) characterization of the hemorrhage location and size ("discrimination network"). Dielectric signatures were learned on a simulated cohort of 666 hemorrhagic stroke and control subjects using 2D stochastic head models. The classification network yielded a stratified K-fold stroke detection accuracy > 94% with an AUC of 0.996, while the discrimination network resulted in a mean squared error of < 0.004 cm and < 0.02 cm, for the stroke localization and size estimation, respectively. We report a novel approach to intelligent diagnostics using microwave wide-band scattering information thus circumventing conventional image-formation.

  View details for DOI 10.1038/s41598-021-03043-y

  View details for Web of Science ID 000733281900034

  View details for PubMedID 34930921

  View details for PubMedCentralID PMC8688451

• Social Determinants of Health Attenuate the Relationship Between Race and Ethnicity and White Matter Hyperintensity Severity but not Microbleed Presence in Patients with Intracerebral Hemorrhage NEUROCRITICAL CARE Bauman, K. M., Yaghi, S., Lewis, A., Agarwal, S., Changa, A., Dogra, S., Litao, M., Sanger, M., Lord, A., Ishida, K., Zhang, C., Czeisler, B., Torres, J., Dehkharghani, S., Frontera, J. A., Melmed, K. R. 2022; 36 (3): 955-963

  Abstract

  The association between race and ethnicity and microvascular disease in patients with intracerebral hemorrhage (ICH) is unclear. We hypothesized that social determinants of health (SDOHs) mediate the relationship between race and ethnicity and severity of white matter hyperintensities (WMHs) and microbleeds in patients with ICH.We performed a retrospective observational cohort study of patients with ICH at two tertiary care hospitals between 2013 and 2020 who underwent magnetic resonance imaging of the brain. Magnetic resonance imaging scans were evaluated for the presence of microbleeds and WMH severity (defined by the Fazekas scale; moderate to severe WMH defined as Fazekas scores 3-6). We assessed for associations between sex, race and ethnicity, employment status, median household income, education level, insurance status, and imaging biomarkers of microvascular disease. A mediation analysis was used to investigate the influence of SDOHs on the associations between race and imaging features. We assessed the relationship of all variables with discharge outcomes.We identified 233 patients (mean age 62 [SD 16]; 48% female) with ICH. Of these, 19% were Black non-Hispanic, 32% had a high school education or less, 21% required an interpreter, 11% were unemployed, and 6% were uninsured. Moderate to severe WMH, identified in 114 (50%) patients, was associated with age, Black non-Hispanic race and ethnicity, highest level of education, insurance status, and history of hypertension, hyperlipidemia, or diabetes (p < 0.05). In the mediation analysis, the proportion of the association between Black non-Hispanic race and ethnicity and the Fazekas score that was mediated by highest level of education was 65%. Microbleeds, present in 130 (57%) patients, was associated with age, highest level of education, and history of diabetes or hypertension (p < 0.05). Age, highest level of education, insurance status, and employment status were associated with discharge modified Rankin Scale scores of 3-6, but race and ethnicity was not.The association between Black non-Hispanic race and ethnicity and moderate to severe WMH lost significance after we adjusted for highest level of education, suggesting that SDOHs may mediate the association between race and ethnicity and microvascular disease.

  View details for DOI 10.1007/s12028-021-01403-0

  View details for Web of Science ID 000730887100002

  View details for PubMedID 34918215

  View details for PubMedCentralID 7056037

• Perfusion Imaging Predicts Favorable Outcomes after Basilar Artery Thrombectomy. Annals of neurology Cereda, C. W., Bianco, G., Mlynash, M., Yuen, N., Qureshi, A. Y., Hinduja, A., Dehkharghani, S., Goldman-Yassen, A. E., Hsieh, K. L., Giurgiutiu, D., Gibson, D., Carrera, E., Alemseged, F., Faizy, T. D., Fiehler, J., Pileggi, M., Campbell, B., Albers, G. W., Heit, J. J. 2021

  Abstract

  OBJECTIVE: Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (Time-to-maximum [Tmax] delay >10 seconds) would have a favorable response to ET compared to patients with more extensive regions involved.METHODS: We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We pre-specified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax >10s) in cerebellum (1 point/hemisphere), pons (2 points), midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS≤3) and unfavorable (CAPS>3) groups. The primary outcome was a favorable functional outcome 90-days after ET (modified Rankin Scale [mRS] 0-3).RESULTS: 103 patients were included. CAPS≤3 patients (87%) had a lower median NIHSS (12.5 [IQR 7-22]) compared to CAPS>3 patients (13%) (23 [IQR 19-36]; p=0.01). Reperfusion was achieved in 84% of all patients with no difference between CAPS groups (p=0.42). 64% of reperfused CAPS≤3 patients had a favorable outcome compared to 8% of non-reperfused CAPS≤3 patients (OR=21.0 [95% CI 2.6-170]; p<0.001). No CAPS>3 patients had a favorable outcome, regardless of reperfusion. In a multivariable regression analysis, CAPS≤3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR 39.25 [95% CI 1.34->999)]; p=0.04).INTERPRETATION: BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/ana.26272

  View details for PubMedID 34786756

• T₁ and T₂ quantification using magnetic resonance fingerprinting in mild traumatic brain injury EUROPEAN RADIOLOGY Gerhalter, T., Cloos, M., Chen, A. M., Dehkharghani, S., Peralta, R., Babb, J. S., Zarate, A., Bushnik, T., Silver, J. M., Im, B. S., Wall, S., Baete, S., Madelin, G., Kirov, I. I. 2022; 32 (2): 1308-1319

  Abstract

  To assess whether MR fingerprinting (MRF)-based relaxation properties exhibit cross-sectional and prospective correlations with patient outcome and compare the results with those from DTI.Clinical imaging, MRF, and DTI were acquired in patients (24 ± 10 days after injury (timepoint 1) and 90 ± 17 days after injury (timepoint 2)) and once in controls. Patient outcome was assessed with global functioning, symptom profile, and neuropsychological testing. ADC and fractional anisotropy (FA) from DTI and T1 and T2 from MRF were compared in 12 gray and white matter regions with Mann-Whitney tests. Bivariate associations between MR measures and outcome were assessed using the Spearman correlation and logistic regression.Data from 22 patients (38 ± 12 years; 17 women) and 18 controls (32 ± 8 years; 12 women) were analyzed. Fourteen patients (37 ± 12 years; 11 women) returned for timepoint 2, while two patients provided only timepoint 2 clinical outcome data. At timepoint 1, there were no differences between patients and controls in T1, T2, and ADC, while FA was lower in mTBI frontal white matter. T1 at timepoint 1 and the change in T1 exhibited more (n = 18) moderate to strong correlations (|r|= 0.6-0.85) with clinical outcome at timepoint 2 than T2 (n = 3), FA (n = 7), and ADC (n = 2). High T1 at timepoint 1, and serially increasing T1, accounted for five of the six MR measures with the highest utility for identification of non-recovered patients at timepoint 2 (AUC > 0.80).T1 derived from MRF was found to have higher utility than T2, FA, and ADC for predicting 3-month outcome after mTBI.• In a region-of-interest approach, FA, ADC, and T1 and T2 all showed limited utility in differentiating patients from controls at an average of 24 and 90 days post-mild traumatic brain injury. • T1 at 24 days, and the serial change in T1, revealed more and stronger predictive correlations with clinical outcome at 90 days than did T2, ADC, or FA. • T1 showed better prospective identification of non-recovered patients at 90 days than ADC, T2, and FA.

  View details for DOI 10.1007/s00330-021-08235-8

  View details for Web of Science ID 000686449000001

  View details for PubMedID 34410458

  View details for PubMedCentralID PMC10303381

• Normative distribution of posterior circulation tissue time-to-maximum: Effects of anatomic variation, tracer kinetics, and implications for patient selection in posterior circulation ischemic stroke JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM Goldman-Yassen, A. E., Straka, M., Uhouse, M., Dehkharghani, S. 2021; 41 (8): 1912-1923

  Abstract

  The generalization of perfusion-based, anterior circulation large vessel occlusion selection criteria to posterior circulation stroke is not straightforward due to physiologic delay, which we posit produces physiologic prolongation of the posterior circulation perfusion time-to-maximum (Tmax). To assess normative Tmax distributions, patients undergoing CTA/CTP for suspected ischemic stroke between 1/2018-3/2019 were retrospectively identified. Subjects with any cerebrovascular stenoses, or with follow-up MRI or final clinical diagnosis of stroke were excluded. Posterior circulation anatomic variations were identified. CTP were processed in RAPID and segmented in a custom pipeline permitting manually-enforced arterial input function (AIF) and perfusion estimations constrained to pre-specified vascular territories. Seventy-one subjects (mean 64 ± 19 years) met inclusion. Median Tmax was significantly greater in the cerebellar hemispheres (right: 3.0 s, left: 2.9 s) and PCA territories (right: 2.9 s; left: 3.3 s) than in the anterior circulation (right: 2.4 s; left: 2.3 s, p < 0.001). Fetal PCA disposition eliminated ipsilateral PCA Tmax delays (p = 0.012). Median territorial Tmax was significantly lower with basilar versus any anterior circulation AIF for all vascular territories (p < 0.001). Significant baseline delays in posterior circulation Tmax are observed even without steno-occlusive disease and vary with anatomic variation and AIF selection. The potential for overestimation of at-risk volumes in the posterior circulation merits caution in future trials.

  View details for DOI 10.1177/0271678X20982395

  View details for Web of Science ID 000679405000008

  View details for PubMedID 33444095

  View details for PubMedCentralID PMC8327115

• Penumbra Consumption Rates Based on Time-to-Maximum Delay and Reperfusion Status: A Post Hoc Analysis of the DEFUSE 3 Trial. Stroke Yaghi, S., Raz, E., Dehkharghani, S., Riina, H., McTaggart, R., Jayaraman, M., Prabhakaran, S., Liebeskind, D. S., Khatri, P., Mac Grory, B., Al-Mufti, F., Lansberg, M., Albers, G., de Havenon, A. 2021: STROKEAHA120033806

  Abstract

  BACKGROUND AND PURPOSE: In patients with acute large vessel occlusion, the natural history of penumbral tissue based on perfusion time-to-maximum (Tmax) delay is not well established in relation to late-window endovascular thrombectomy. In this study, we sought to evaluate penumbra consumption rates for Tmax delays in patients with large vessel occlusion evaluated between 6 and 16 hours from last known normal.METHODS: This is a post hoc analysis of the DEFUSE 3 trial (The Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke), which included patients with an acute ischemic stroke due to anterior circulation occlusion within 6 to 16 hours of last known normal. The primary outcome is percentage penumbra consumption, defined as (24-hour magnetic resonance imaging infarct volume-baseline core infarct volume)/(Tmax 6 or 10 s volume-baseline core volume). We stratified the cohort into 4 categories based on treatment modality and Thrombolysis in Cerebral Infarction (TICI score; untreated, TICI 0-2a, TICI 2b, and TICI3) and calculated penumbral consumption rates in each category.RESULTS: We included 141 patients, among whom 68 were untreated. In the untreated versus TICI 3 patients, a median (interquartile range) of 53.7% (21.2%-87.7%) versus 5.3% (1.1%-14.6%) of penumbral tissue was consumed based on Tmax >6 s (P<0.001). In the same comparison for Tmax>10 s, we saw a difference of 165.4% (interquartile range, 56.1%-479.8%) versus 25.7% (interquartile range, 3.2%-72.1%; P<0.001). Significant differences were not demonstrated between untreated and TICI 0-2a patients for penumbral consumption based on Tmax >6 s (P=0.52) or Tmax >10 s (P=0.92).CONCLUSIONS: Among extended window endovascular thrombectomy patients, Tmax >10-s mismatch volume may comprise large volumes of salvageable tissue, whereas nearly half the Tmax >6-s mismatch volume may remain viable in untreated patients at 24 hours.

  View details for DOI 10.1161/STROKEAHA.120.033806

  View details for PubMedID 34157865

• Do Prior Iodine Contrast Injections Affect Cerebral Blood Flow Measurement on CT Perfusion Studies of Patients with Large-Vessel Occlusions? AMERICAN JOURNAL OF NEURORADIOLOGY Amukotuwa, S. A., Bammer, R., Dehkharghani, S. 2021; 42 (8): E56-E57

  View details for DOI 10.3174/ajnr.A7139

  View details for Web of Science ID 000655513500001

  View details for PubMedID 33985957

  View details for PubMedCentralID PMC8367623

• Prediction of Infarct Volume at the 24 Hours after Late Window Presentation with Perfusion Imaging in Patients with Anterior Circulation Large Vessel Occlusion Agarwal, S., Raz, E., Dehkharghani, S., Christensen, S., Lansberg, M., Yaghi, S., de Havenon, A. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for Web of Science ID 000729283602208

• Global decrease in brain sodium concentration after mild traumatic brain injury BRAIN COMMUNICATIONS Gerhalter, T., Chen, A. M., Dehkharghani, S., Peralta, R., Adlparvar, F., Babb, J. S., Bushnik, T., Silver, J. M., Im, B. S., Wall, S. P., Brown, R., Baete, S. H., Kirov, I. I., Madelin, G. 2021; 3 (2): fcab051

  Abstract

  The pathological cascade of tissue damage in mild traumatic brain injury is set forth by a perturbation in ionic homeostasis. However, whether this class of injury can be detected in vivo and serve as a surrogate marker of clinical outcome is unknown. We employ sodium MRI to test the hypotheses that regional and global total sodium concentrations: (i) are higher in patients than in controls and (ii) correlate with clinical presentation and neuropsychological function. Given the novelty of sodium imaging in traumatic brain injury, effect sizes from (i), and correlation types and strength from (ii), were compared to those obtained using standard diffusion imaging metrics. Twenty-seven patients (20 female, age 35.9 ± 12.2 years) within 2 months after injury and 19 controls were scanned with proton and sodium MRI at 3 Tesla. Total sodium concentration, fractional anisotropy and apparent diffusion coefficient were obtained with voxel averaging across 12 grey and white matter regions. Linear regression was used to obtain global grey and white matter total sodium concentrations. Patient outcome was assessed with global functioning, symptom profiles and neuropsychological function assessments. In the regional analysis, there were no statistically significant differences between patients and controls in apparent diffusion coefficient, while differences in sodium concentration and fractional anisotropy were found only in single regions. However, for each of the 12 regions, sodium concentration effect sizes were uni-directional, due to lower mean sodium concentration in patients compared to controls. Consequently, linear regression analysis found statistically significant lower global grey and white matter sodium concentrations in patients compared to controls. The strongest correlation with outcome was between global grey matter sodium concentration and the composite z-score from the neuropsychological testing. In conclusion, both sodium concentration and diffusion showed poor utility in differentiating patients from controls, and weak correlations with clinical presentation, when using a region-based approach. In contrast, sodium linear regression, capitalizing on partial volume correction and high sensitivity to global changes, revealed high effect sizes and associations with patient outcome. This suggests that well-recognized sodium imbalances in traumatic brain injury are (i) detectable non-invasively; (ii) non-focal; (iii) occur even when the antecedent injury is clinically mild. Finally, in contrast to our principle hypothesis, patients' sodium concentrations were lower than controls, indicating that the biological effect of traumatic brain injury on the sodium homeostasis may differ from that in other neurological disorders. Note: This figure has been annotated.

  View details for DOI 10.1093/braincomms/fcab051

  View details for Web of Science ID 000667313900043

  View details for PubMedID 33928248

  View details for PubMedCentralID PMC8066885

• Age-adjusted infarct volume cut-off points improve stroke outcome prognostication beyond modeling with age and infarct volume JOURNAL OF NEUROINTERVENTIONAL SURGERY Bouslama, M., Haussen, D. C., Rodrigues, G., Barreira, C. M., Dehkharghani, S., Frankel, M. R., Nogueira, R. G. 2022; 14 (2): 122-+

  Abstract

  Age and infarct volume are among the most powerful predictors of outcome after large vessel occlusion acute strokes (LVOS).To study the impact of age-adjusted final infarct volume (FIV) on functional outcomes.Review of a prospectively collected thrombectomy database at a tertiary care center between September 2010 and February 2018. Consecutive patients with anterior circulation LVOS who achieved full reperfusion (modified Thrombolysis in Cerebral Infarction 3) were categorized into four age groups: (G1) <60 years, (G2) 60-69, (G3) 70-79, (G4) ≥80 years. The Youden Index was used to identify the optimal FIV cut-off point for good outcome (modified Rankin Scale score 0-2) discrimination in each group and the overall population. The predictive ability of these specific thresholds was evaluated using binary logistic regressions and compared with the non-age-adjusted cut-off point.516 patients were analyzed (G1: n=171, G2: n=130, G3: n=103, G4: n=112). Patients with poor outcome had a larger FIV in each group (p<0.01 for all). The target FIV cut-off point decreased with increased age: G1: 45.7 mL (sensitivity 56%, specificity 80%); G2: 30.4 mL (sensitivity 63%, specificity 75%); G3: 20.2 mL (sensitivity 76%, specificity 65%); G4: 16.9 mL (sensitivity 68%, specificity 70%). The non-age-adjusted cut-off point was 19.2 mL (sensitivity 70%, specificity 59%).In multivariate analysis, adjusting for confounders including age and FIV, achieving a FIV less than the age-adjusted threshold was an independent predictor of good outcome (aOR=2.72, 95% CI 1.41 to 5.24, p<0.001). In contrast, a similar model including the non-age-adjusted target cut-off point failed to reveal an association with good outcome (aOR=1.72, 95% CI 0.93 to 3.19, p<0.085). Furthermore, the latter model had a weaker outcome predictive ability as assessed by the Akaike information criterion (409 vs 403).Age-adjusted infarct volume represents a strong outcome discriminator beyond age and infarct volume in isolation and might help to refine patient selection and improve outcome prognostication in stroke thrombectomy.

  View details for DOI 10.1136/neurintsurg-2020-017066

  View details for Web of Science ID 000727458200001

  View details for PubMedID 33722959

• Prediction of Infarct Volume at the 24 Hours After Late Window Presentation With Perfusion Imaging in Patients With Anterior Circulation Large Vessel Occlusion Agarwal, S., Raz, E., Dehkharghani, S., Christensen, S., Lansberg, M. G., Albers, G., Yaghi, S., De Havenon, A. H. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for DOI 10.1161/str.52.suppl_1.P505

  View details for Web of Science ID 000670883500620

• Hemorrhagic Stroke in the Setting of COVID-19 is Associated With Anticoagulation Use. Kvernland, A., Kumar, A., Yaghi, S., Raz, E., Frontera, J., Lewis, A., Czeisler, B., Kahn, D., Zhou, T., Ishida, K., Torres, J. L., Riina, H., Shapiro, M., Nossek, E., Nelson, P. K., Tanweer, O., Gordon, D., Jain, R., Dehkharghani, S., Henninger, N., De Havenon, A. H., Mac Grory, B., Lord, A., Melmed, K. R. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for DOI 10.1161/str.52.suppl_1.P100

  View details for Web of Science ID 000670883500223

• RAPID-LVO for Automated Detection of Intracranial Large Vessel Occlusion in Ct Angiography of the Brain. Dehkharghani, S., Lansberg, M. G., Venkatsubramanian, C., Cereda, C. W., Lima, F. O., Coelho, H., Rocha, F. A., Qureshi, A. Y., Haerian, H. D., Montalverne, F., Copeland, K., Heit, J. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for DOI 10.1161/str.52.suppl_1.P337

  View details for Web of Science ID 000670883500454

• Penumbra Consumption Rates Based on T Max Delay and Reperfusion Status: A Post-Hoc Analysis of the Defuse-3 Trial Yaghi, S., Raz, E., Dehkharghani, S., Riina, H., McTaggart, R., Jayaraman, M., Prabhakaran, S., Liebeskind, D. S., Khatri, P., Mac Grory, B. C., Lansberg, M. G., Albers, G. W., De Havenon, A. H. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for DOI 10.1161/str.52.suppl_1.31

  View details for Web of Science ID 000670883500031

• Letter by Amukotuwa and Dehkharghani Regarding Article, "Deep Learning Based Software to Identify Large Vessel Occlusion on Noncontrast Computed Tomography" STROKE Amukotuwa, S. A., Dehkharghani, S. 2021; 52 (2): E61-E62

  View details for DOI 10.1161/STROKEAHA.120.032604

  View details for Web of Science ID 000639316400005

  View details for PubMedID 33493047

• High-Performance Automated Anterior Circulation CT Angiographic Clot Detection in Acute Stroke: A Multireader Comparison. Radiology Dehkharghani, S. n., Lansberg, M. n., Venkatsubramanian, C. n., Cereda, C. n., Lima, F. n., Coelho, H. n., Rocha, F. n., Qureshi, A. n., Haerian, H. n., Mont'Alverne, F. n., Copeland, K. n., Heit, J. n. 2021: 202734

  Abstract

  Background Identification of large vessel occlusion (LVO) is critical to the management of acute ischemic stroke and prerequisite to endovascular therapy in recent trials. Increasing volumes and data complexity compel the development of fast, reliable, and automated tools for LVO detection to facilitate acute imaging triage. Purpose To investigate the performance of an anterior circulation LVO detection platform in a large mixed sample of individuals with and without LVO at cerebrovascular CT angiography (CTA). Materials and Methods In this retrospective analysis, CTA data from recent cerebrovascular trials (CRISP [ClinicalTrials.gov NCT01622517] and DASH) were enriched with local repositories from 11 worldwide sites to balance demographic and technical variables in LVO-positive and LVO-negative examinations. CTA findings were reviewed independently by two neuroradiologists from different institutions for intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) M1 LVO; these observers were blinded to all clinical variables and outcomes. An automated analysis platform was developed and tested for prediction of LVO presence and location relative to reader consensus. Discordance between readers with respect to LVO presence or location was adjudicated by a blinded tertiary reader at a third institution. Sensitivity, specificity, and receiver operating characteristics were assessed by an independent statistician, and subgroup analyses were conducted. Prespecified performance thresholds were set at a lower bound of the 95% CI of sensitivity and specificity of 0.8 or greater at mean times to notification of less than 3.5 minutes. Results A total of 217 study participants (mean age, 64 years ± 16 [standard deviation]; 116 men; 109 with positive findings of LVO) were evaluated. Prespecified performance thresholds were exceeded (sensitivity, 105 of 109 [96%; 95% CI: 91, 99]; specificity, 106 of 108 [98%; 95% CI: 94, 100]). Sensitivity and specificity estimates across age, sex, location, and vendor subgroups exceeded 90%. The area under the receiver operating characteristic curve was 99% (95% CI: 97, 100). Mean processing and notification time was 3 minutes 18 seconds. Conclusion The results confirm the feasibility of fast automated high-performance detection of intracranial internal carotid artery and middle cerebral artery M1 occlusions. © RSNA, 2021 See also the editorial by Kloska in this issue.

  View details for DOI 10.1148/radiol.2021202734

  View details for PubMedID 33434110

• Neuroimaging in Pediatric Stroke and Cerebrovascular Disease Stroke Goldman-Yassen, A., Dehkharghani, S. Exon Publications. 2021; 1

  View details for DOI 10.36255/exonpublications.stroke.pediatricstroke.2021

• Neuroimaging in Perinatal Stroke and Cerebrovascular Disease Stroke Goldman-Yassen, A. edited by Dehkharghani, S. Exon Publications. 2021; 1

  View details for DOI 10.36255/exonpublications.stroke.perinatalstroke.2021

• Automated Cerebral Hemorrhage Detection Using RAPID. AJNR. American journal of neuroradiology Heit, J. J., Coelho, H., Lima, F. O., Granja, M., Aghaebrahim, A., Hanel, R., Kwok, K., Haerian, H., Cereda, C. W., Venkatasubramanian, C., Dehkharghani, S., Carbonera, L. A., Wiener, J., Copeland, K., Mont'Alverne, F. 2020

  Abstract

  BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is an important event that is diagnosed on head NCCT. Increased NCCT utilization in busy hospitals may limit timely identification of ICH. RAPID ICH is an automated hybrid 2D-3D convolutional neural network application designed to detect ICH that may allow for expedited ICH diagnosis. We determined the accuracy of RAPID ICH for ICH detection and ICH volumetric quantification on NCCT.MATERIALS AND METHODS: NCCT scans were evaluated for ICH by RAPID ICH. Consensus detection of ICH by 3 neuroradiology experts was used as the criterion standard for RAPID ICH comparison. ICH volume was also automatically determined by RAPID ICH in patients with intraparenchymal or intraventricular hemorrhage and compared with manually segmented ICH volumes by a single neuroradiology expert. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID ICH were determined.RESULTS: We included 308 studies. RAPID ICH correctly identified 151/158 ICH cases and 143/150 ICH-negative cases, which resulted in high sensitivity (0.956, CI: 0.911-0.978), specificity (0.953, CI: 0.907-0.977), positive predictive value (0.956, CI: 0.911-0.978), and negative predictive value (0.953, CI: 0.907-0.977) for ICH detection. The positive likelihood ratio (20.479, CI 9.928-42.245) and negative likelihood ratio (0.046, CI 0.023-0.096) for ICH detection were similarly favorable. RAPID ICH volumetric quantification for intraparenchymal and intraventricular hemorrhages strongly correlated with expert manual segmentation (correlation coefficient r=0.983); the median absolute error was 3mL.CONCLUSIONS: RAPID ICH is highly accurate in the detection of ICH and in the volumetric quantification of intraparenchymal and intraventricular hemorrhages.

  View details for DOI 10.3174/ajnr.A6926

  View details for PubMedID 33361378

• The Effect of Hyperglycemia on Infarct Growth after Reperfusion: An Analysis of the DEFUSE 3 trial. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association Yaghi, S., Dehkharghani, S., Raz, E., Jayaraman, M., Tanweer, O., Grory, B. M., Henninger, N., Lansberg, M. G., Albers, G. W., Havenon, A. d. 2020; 30 (1): 105380

  Abstract

  BACKGROUND AND PURPOSE: Brain infarct growth, despite successful reperfusion, decreases the likelihood of good functional outcome after ischemic stroke. In patients undergoing reperfusion, admission glucose is associated with poor outcome but the effect of glucose level on infarct growth is not well studied.MATERIALS AND METHODS: This is a secondary analysis of the DEFUSE 3 trial. The primary predictor was baseline glucose level and the primary outcome is the change of the ischemic core volume from the baseline to 24-hour follow-up imaging (∆core), transformed as a cube root to reduce right skew. We included DEFUSE 3 patients who were randomized to endovascular therapy, had perfusion imaging data at baseline, an MRI at 24 hours, and who achieved TICI 2b or 3. Linear regression models, both unadjusted and adjusted, were fit to the primary outcome and all models included the baseline core volume as a covariate to normalize ∆core.RESULTS: We identified 62 patients who met our inclusion criteria. The mean age was 68.1±13.1 (years), 48.4% (30/62) were men, and the median (IQR) cube root of ∆core was 2.8 (2.0-3.8) mL. There was an association between baseline glucose level and normalized ∆core in unadjusted analysis (beta coefficient 0.010, p = 0.01) and after adjusting for potential confounders (beta coefficient 0.008, p = 0.03).CONCLUSION: In acute ischemic stroke patients with large vessel occlusion undergoing successful endovascular reperfusion, baseline hyperglycemia is associated with infarction growth. Further study is needed to establish potential neuroprotective benefits of aggressive glycemic control prior to and after reperfusion.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2020.105380

  View details for PubMedID 33166769

• Spontaneous, Intrasphenoidal Rupture of Ecchordosis Physaliphora with Pneumocephalus Captured During Serial Imaging and Clinical Follow-Up: Pathoanatomic Features and Management WORLD NEUROSURGERY Derakhshani, A., Livingston, S., William, C., Lieberman, S., Young, M., Pacione, D., Dehkharghani, S. 2020; 141: 85-90

  Abstract

  Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intrasphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid leak, definitively captured over serial imaging during clinical and radiologic surveillance.A 68-year old woman with Marfan syndrome presented to the emergency department with the worst headache of her life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a transsphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrated an apparently enlarging transsphenoidal defect which was managed by endoscopic transnasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect.This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare but potentially significant complications of EP and highlights management options.

  View details for DOI 10.1016/j.wneu.2020.05.220

  View details for Web of Science ID 000566483400026

  View details for PubMedID 32492548

• Anticoagulation use and Hemorrhagic Stroke in SARS-CoV-2 Patients Treated at a New York Healthcare System NEUROCRITICAL CARE Kvernland, A., Kumar, A., Yaghi, S., Raz, E., Frontera, J., Lewis, A., Czeisler, B., Kahn, D., Zhou, T., Ishida, K., Torres, J., Riina, H. A., Shapiro, M., Nossek, E., Nelson, P. K., Tanweer, O., Gordon, D., Jain, R., Dehkharghani, S., Henninger, N., de Havenon, A., Mac Grory, B., Lord, A., Melmed, K. 2021; 34 (3): 748-759

  Abstract

  While the thrombotic complications of COVID-19 have been well described, there are limited data on clinically significant bleeding complications including hemorrhagic stroke. The clinical characteristics, underlying stroke mechanism, and outcomes in this particular subset of patients are especially salient as therapeutic anticoagulation becomes increasingly common in the treatment and prevention of thrombotic complications of COVID-19.We conducted a retrospective cohort study of patients with hemorrhagic stroke (both non-traumatic intracerebral hemorrhage and spontaneous non-aneurysmal subarachnoid hemorrhage) who were hospitalized between March 1, 2020, and May 15, 2020, within a major healthcare system in New York, during the coronavirus pandemic. Patients with hemorrhagic stroke on admission and who developed hemorrhage during hospitalization were both included. We compared the clinical characteristics of patients with hemorrhagic stroke and COVID-19 to those without COVID-19 admitted to our hospital system between March 1, 2020, and May 15, 2020 (contemporary controls), and March 1, 2019, and May 15, 2019 (historical controls). Demographic variables and clinical characteristics between the individual groups were compared using Fischer's exact test for categorical variables and nonparametric test for continuous variables. We adjusted for multiple comparisons using the Bonferroni method.During the study period in 2020, out of 4071 patients who were hospitalized with COVID-19, we identified 19 (0.5%) with hemorrhagic stroke. Of all COVID-19 with hemorrhagic stroke, only three had isolated non-aneurysmal SAH with no associated intraparenchymal hemorrhage. Among hemorrhagic stroke in patients with COVID-19, coagulopathy was the most common etiology (73.7%); empiric anticoagulation was started in 89.5% of these patients versus 4.2% in contemporary controls (p ≤ .001) and 10.0% in historical controls (p ≤ .001). Compared to contemporary and historical controls, patients with COVID-19 had higher initial NIHSS scores, INR, PTT, and fibrinogen levels. Patients with COVID-19 also had higher rates of in-hospital mortality (84.6% vs. 4.6%, p ≤ 0.001). Sensitivity analyses excluding patients with strictly subarachnoid hemorrhage yielded similar results.We observed an overall low rate of imaging-confirmed hemorrhagic stroke among patients hospitalized with COVID-19. Most hemorrhages in patients with COVID-19 infection occurred in the setting of therapeutic anticoagulation and were associated with increased mortality. Further studies are needed to evaluate the safety and efficacy of therapeutic anticoagulation in patients with COVID-19.

  View details for DOI 10.1007/s12028-020-01077-0

  View details for Web of Science ID 000562361800001

  View details for PubMedID 32839867

  View details for PubMedCentralID PMC7444897

• Cerebral Venous Thrombosis Associated with COVID-19 AMERICAN JOURNAL OF NEURORADIOLOGY Cavalcanti, D. D., Raz, E., Shapiro, M., Dehkharghani, S., Yaghi, S., Lillemoe, K., Nossek, E., Torres, J., Jain, R., Riina, H. A., Radmanesh, A., Nelson, P. K. 2020; 41 (8): 1370-1376

  Abstract

  Despite the severity of coronavirus disease 2019 (COVID-19) being more frequently related to acute respiratory distress syndrome and acute cardiac and renal injuries, thromboembolic events have been increasingly reported. We report a unique series of young patients with COVID-19 presenting with cerebral venous system thrombosis. Three patients younger than 41 years of age with confirmed Severe Acute Respiratory Syndrome coronavirus 2 (SARS-Cov-2) infection had neurologic findings related to cerebral venous thrombosis. They were admitted during the short period of 10 days between March and April 2020 and were managed in an academic institution in a large city. One patient had thrombosis in both the superficial and deep systems; another had involvement of the straight sinus, vein of Galen, and internal cerebral veins; and a third patient had thrombosis of the deep medullary veins. Two patients presented with hemorrhagic venous infarcts. The median time from COVID-19 symptoms to a thrombotic event was 7 days (range, 2-7 days). One patient was diagnosed with new-onset diabetic ketoacidosis, and another one used oral contraceptive pills. Two patients were managed with both hydroxychloroquine and azithromycin; one was treated with lopinavir-ritonavir. All patients had a fatal outcome. Severe and potentially fatal deep cerebral thrombosis may complicate the initial clinical presentation of COVID-19. We urge awareness of this atypical manifestation.

  View details for DOI 10.3174/ajnr.A6644

  View details for Web of Science ID 000562443900019

  View details for PubMedID 32554424

  View details for PubMedCentralID PMC7658892

• SARS-CoV-2 and Stroke in a New York Healthcare System STROKE Yaghi, S., Ishida, K., Torres, J., Mac Grory, B., Raz, E., Humbert, K., Henninger, N., Trivedi, T., Lillemoe, K., Alam, S., Sanger, M., Kim, S., Scher, E., Dehkharghani, S., Wachs, M., Tanweer, O., Volpicelli, F., Bosworth, B., Lord, A., Frontera, J. 2020; 51 (7): 2002-2011

  Abstract

  With the spread of coronavirus disease 2019 (COVID-19) during the current worldwide pandemic, there is mounting evidence that patients affected by the illness may develop clinically significant coagulopathy with thromboembolic complications including ischemic stroke. However, there is limited data on the clinical characteristics, stroke mechanism, and outcomes of patients who have a stroke and COVID-19.We conducted a retrospective cohort study of consecutive patients with ischemic stroke who were hospitalized between March 15, 2020, and April 19, 2020, within a major health system in New York, the current global epicenter of the pandemic. We compared the clinical characteristics of stroke patients with a concurrent diagnosis of COVID-19 to stroke patients without COVID-19 (contemporary controls). In addition, we compared patients to a historical cohort of patients with ischemic stroke discharged from our hospital system between March 15, 2019, and April 15, 2019 (historical controls).During the study period in 2020, out of 3556 hospitalized patients with diagnosis of COVID-19 infection, 32 patients (0.9%) had imaging proven ischemic stroke. Cryptogenic stroke was more common in patients with COVID-19 (65.6%) as compared to contemporary controls (30.4%, P=0.003) and historical controls (25.0%, P<0.001). When compared with contemporary controls, COVID-19 positive patients had higher admission National Institutes of Health Stroke Scale score and higher peak D-dimer levels. When compared with historical controls, COVID-19 positive patients were more likely to be younger men with elevated troponin, higher admission National Institutes of Health Stroke Scale score, and higher erythrocyte sedimentation rate. Patients with COVID-19 and stroke had significantly higher mortality than historical and contemporary controls.We observed a low rate of imaging-confirmed ischemic stroke in hospitalized patients with COVID-19. Most strokes were cryptogenic, possibly related to an acquired hypercoagulability, and mortality was increased. Studies are needed to determine the utility of therapeutic anticoagulation for stroke and other thrombotic event prevention in patients with COVID-19.

  View details for DOI 10.1161/STROKEAHA.120.030335

  View details for Web of Science ID 000544979200028

  View details for PubMedID 32432996

  View details for PubMedCentralID PMC7258764

• Mechanical Thrombectomy in Nonagenarians: A Propensity Score Matched Analysis JOURNAL OF STROKE & CEREBROVASCULAR DISEASES Agarwal, S., Huang, J., Scher, E., Farkas, J., Arcot, K., Gordon, D., Turkel-Parrella, D., Tiwari, A., Liff, J., Yaghi, S., Dehkharghani, S., Ishida, K., Riina, H., Frontera, J. A. 2020; 29 (7): 104870

  Abstract

  Little data exists on outcomes of mechanical thrombectomy (MT) in nonagenarians. We aimed to compare the procedural and discharge outcomes of MT for acute ischemic stroke (AIS) in nonagenarians versus younger patients.Procedural outcomes and discharge disposition were compared in propensity score-matched groups of nonagenarians versus patients aged≤69 with AIS who underwent MT. Patients aged 70-89 were excluded in order to compare nonagenarians to a younger cohort that most closely approximates the age of patients in the seminal MT trials. Good discharge disposition was defined as a discharge to home or acute rehabilitation.Of 3010 AIS patients, 46/297(16%) nonagenarians underwent MT compared to 159/1337(12%) aged≤69 (P = 0.091). Of 78 propensity score-matched patients (N = 39 ≥90, N = 39 ≤69), the median admission NIHSS was 22 versus 20, median ASPECTS was 9 versus 9, pre-stroke mRS<4 was 82% versus 87%, 18% versus 8% received IV tPA, and mTICI≥2b was 90% versus 90%, respectively (all P>0.05). Revascularization time (569 versus 372 min), door to groin puncture time (82 versus 71 min) and groin puncture to revascularization times (39 versus 24 min) were similar in between nonagenarians and ≤69, respectively (both P>0.05). Symptomatic ICH (2.6% versus 10.3%; p = 0.165) and in-hospital death rates (10% vs 26%; p = 0.077) trended lower among nonagenarians versus aged≤69. Good discharge disposition occurred in 44% of nonagenarians versus 51% aged≤69 years (p = 0.496).In propensity score analysis, 90% of nonagenarians achieved successful recanalization and almost half (44%) were discharged to home/acute rehabilitation, which was similar to a younger (aged≤69 years) cohort.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2020.104870

  View details for Web of Science ID 000539258500010

  View details for PubMedID 32414578

• Stroke Treatment Delay Limits Outcome After Mechanical Thrombectomy: Stratification by Arrival Time and ASPECTS JOURNAL OF NEUROIMAGING Snyder, T., Agarwal, S., Huang, J., Ishida, K., Flusty, B., Frontera, J., Lord, A., Torres, J., Zhang, C., Rostanski, S., Favate, A., Lillemoe, K., Sanger, M., Kim, S., Humbert, K., Scher, E., Dehkharghani, S., Raz, E., Shapiro, M., Nelson, P., Gordon, D., Tanweer, O., Nossek, E., Farkas, J., Liff, J., Turkel-Parrella, D., Tiwari, A., Riina, H., Yaghi, S. 2020; 30 (5): 625-630

  Abstract

  Mechanical thrombectomy (MT) has helped many patients achieve functional independence. The effect of time-to-treatment based in specific epochs and as related to Alberta Stroke Program Early CT Score (ASPECTS) has not been established. The goal of the study was to evaluate the association between last known normal (LKN)-to-puncture time and good functional outcome.We conducted a retrospective cohort study of prospectively collected acute ischemic stroke patients undergoing MT for large vessel occlusion. We used binary logistic regression models adjusted for age, Modified Treatment in Cerebral Ischemia score, initial National Institutes of Health Stroke Scale, and noncontrast CT ASPECTS to assess the association between LKN-to-puncture time and favorable outcome defined as Modified Rankin Score 0-2 on discharge.Among 421 patients, 328 were included in analysis. Increased LKN-to-puncture time was associated with decreased probability of good functional outcome (adjusted odds ratio [aOR] ratio per 15-minute delay = .98; 95% confidence interval [CI], .97-.99; P = .001). This was especially true when LKN-puncture time was 0-6 hours (aOR per 15-minute delay = .94; 95% CI, .89-.99; P = .05) or ASPECTS 8-10 (aOR = .98; 95% CI, .97-.99; P = .002) as opposed to when LKN-puncture time was 6-24 hours (aOR per 15-minute delay = .99; 95% CI, .97-1.00; P = .16) and ASPECTS <8 (aOR = .98; 95% CI, .93-1.03; P = .37).Decreased LKN-groin puncture time improves outcome particularly in those with good ASPECTS presenting within 6 hours. Strategies to decrease reperfusion times should be investigated, particularly in those in the early time window and with good ASPECTS.

  View details for DOI 10.1111/jon.12729

  View details for Web of Science ID 000543563100001

  View details for PubMedID 32592619

• MR Thermometry in Cerebrovascular Disease: Physiologic Basis, Hemodynamic Dependence, and a New Frontier in Stroke Imaging AMERICAN JOURNAL OF NEURORADIOLOGY Dehkharghani, S., Qiu, D. 2020; 41 (4): 555-565

  Abstract

  The remarkable temperature sensitivity of the brain is widely recognized and has been studied for its role in the potentiation of ischemic and other neurologic injuries. Pyrexia frequently complicates large-vessel acute ischemic stroke and develops commonly in critically ill neurologic patients; the profound sensitivity of the brain even to minor intraischemic temperature changes, together with the discovery of brain-to-systemic as well as intracerebral temperature gradients, has thus compelled the exploration of cerebral thermoregulation and uncovered its immutable dependence on cerebral blood flow. A lack of pragmatic and noninvasive tools for spatially and temporally resolved brain thermometry has historically restricted empiric study of cerebral temperature homeostasis; however, MR thermometry (MRT) leveraging temperature-sensitive nuclear magnetic resonance phenomena is well-suited to bridging this long-standing gap. This review aims to introduce the reader to the following: 1) fundamental aspects of cerebral thermoregulation, 2) the physical basis of noninvasive MRT, and 3) the physiologic interdependence of cerebral temperature, perfusion, metabolism, and viability.

  View details for DOI 10.3174/ajnr.A6455

  View details for Web of Science ID 000526820700008

  View details for PubMedID 32139425

  View details for PubMedCentralID PMC7144635

• Peri-procedural stroke or death in stenting of symptomatic severe intracranial stenosis JOURNAL OF NEUROINTERVENTIONAL SURGERY Yaghi, S., Khatri, P., de Havenon, A., Yeatts, S., Chang, A. D., Cutting, S., Mac Grory, B., Burton, T., Jayaraman, M., McTaggart, R. A., Fiorella, D., Derdeyn, C., Zaidat, O. O., Dehkharghani, S., Amin-Hanjani, S., Furie, K., Prahbakaran, S., Liebeskind, D. 2020; 12 (4): 374-379

  Abstract

  There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial.This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome.We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437).In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting.SAMMPRIS NCT00576693; Results.

  View details for DOI 10.1136/neurintsurg-2019-015225

  View details for Web of Science ID 000524256500010

  View details for PubMedID 31484697

  View details for PubMedCentralID PMC8022354

• Possible Empirical Evidence of Glymphatic System on Computed Tomography After Endovascular Perforations WORLD NEUROSURGERY Raz, E., Dehkharghani, S., Shapiro, M., Nossek, E., Jain, R., Zhang, C., Ishida, K., Tanweer, O., Peschillo, S., Nelson, P. 2020; 134: E400-E404

  Abstract

  The glial-lymphatic pathway is a fluid-clearance pathway consisting of a para-arterial route for the flow of cerebrospinal fluid along perivascular spaces and subsequently toward the brain interstitium. In this case series, we aim to investigate an empirical demonstration of glymphatic clearance of extravasated iodine following perforation incurred during endovascular therapy on serial computed tomography.Six consecutive cases of endovascular perforation during thrombectomy performed between 2005 and 2018 were retrospectively collected by searching our internal database of total 446 thrombectomies. Two cases were excluded because care was withdrawn shortly following the procedure and no follow-up imaging was available. One case was excluded because a ventricular drain was placed. Three cases were hence included in this analysis.All 3 cases demonstrated progressive absorption of contrast by the brain parenchyma with eventual contrast disappearance.We described a likely in vivo computed tomography correlate of the glymphatic system in a cohort of patients who sustained intraprocedural extravasation during thrombectomy for acute ischemic stroke.

  View details for DOI 10.1016/j.wneu.2019.10.089

  View details for Web of Science ID 000512878200048

  View details for PubMedID 31655242

• Mild fever as a catalyst for consumption of the ischaemic penumbra despite endovascular reperfusion BRAIN COMMUNICATIONS Dehkharghani, S., Yaghi, S., Bowen, M. T., Pisani, L., Scher, E., Haussen, D. C., Nogueira, R. G. 2020; 2 (2): fcaa116

  Abstract

  Cerebrovascular ischaemia is potentiated by hyperthermia, and even mild temperature elevation has proved detrimental to ischaemic brain. Infarction progression following endovascular reperfusion relates to multiple patient-specific and procedural variables; however, the potential influence of mild systemic temperature fluctuations is not fully understood. This study aims to assess the relationship between systemic temperatures in the early aftermath of acute ischaemic stroke and the loss of at-risk penumbral tissues, hypothesizing consumption of the ischaemic penumbra as a function of systemic temperatures, irrespective of reperfusion status. A cross-sectional, retrospective evaluation of a single-institution, prospectively collected endovascular therapy registry was conducted. Patients with anterior circulation, large vessel occlusion acute ischaemic stroke who underwent initial CT perfusion, and in whom at least four-hourly systemic temperatures were recorded beginning from presentation and until the time of final imaging outcome were included. Initial CT perfusion core and penumbra volumes and final MRI infarction volumes were computed. Systemic temperature indices including temperature maxima were recorded, and pre-defined temperature thresholds varying between 37°C and 38°C were examined in unadjusted and adjusted regression models which included glucose, collateral status, reperfusion status, CT perfusion-to-reperfusion delay, general anaesthesia and antipyretic exposure. The primary outcome was the relative consumption of the penumbra, reflecting normalized growth of the at-risk tissue volume ≥10%. The final study population comprised 126 acute ischaemic stroke subjects (mean 63 ± 14.5 years, 63% women). The primary outcome of penumbra consumption ≥10% occurred in 51 (40.1%) subjects. No significant differences in baseline characteristics were present between groups, with the exception of presentation glucose (118 ± 26.6 without versus 143.1 ± 61.6 with penumbra consumption, P = 0.009). Significant differences in the likelihood of penumbra consumption relating to systemic temperature maxima were observed [37°C (interquartile range 36.5 - 37.5°C) without versus 37.5°C (interquartile range 36.8 - 38.2°C) with penumbra consumption, P = 0.001]. An increased likelihood of penumbra consumption was observed for temperature maxima in unadjusted (odds ratio 3.57, 95% confidence interval 1.65 - 7.75; P = 0.001) and adjusted (odds ratio 3.06, 95% confidence interval 1.33 - 7.06; P = 0.009) regression models. Significant differences in median penumbra consumption were present at a pre-defined temperature maxima threshold of 37.5°C [4.8 ml (interquartile range 0 - 11.5 ml) versus 21.1 ml (0 - 44.7 ml) for subjects not reaching or reaching the threshold, respectively, P = 0.007]. Mild fever may promote loss of the ischaemic penumbra irrespective of reperfusion, potentially influencing successful salvage of at-risk tissue volumes following acute ischaemic stroke.

  View details for DOI 10.1093/braincomms/fcaa116

  View details for Web of Science ID 000639431800057

  View details for PubMedID 33033801

  View details for PubMedCentralID PMC7532660

• Fast Automatic Detection of Large Vessel Occlusions on CT Angiography. Stroke Amukotuwa, S. A., Straka, M., Dehkharghani, S., Bammer, R. 2019: STROKEAHA119027076

  Abstract

  Background and Purpose- Accurate and rapid detection of anterior circulation large vessel occlusion (LVO) is of paramount importance in patients with acute stroke due to the potentially rapid infarction of at-risk tissue and the limited therapeutic window for endovascular clot retrieval. Hence, the optimal threshold of a new, fully automated software-based approach for LVO detection was determined, and its diagnostic performance evaluated in a large cohort study. Methods- For this retrospective study, data were pooled from: 2 stroke trials, DEFUSE 2 (n=62; 07/08-09/11) and DEFUSE 3 (n=213; 05/17-05/18); a cohort of endovascular clot retrieval candidates (n=82; August 2, 2014-August 30, 2015) and normals (n=111; June 6, 2017-January 28, 2019) from a single quaternary center; and code stroke patients (n=501; January 1, 2017-December 31, 2018) from a single regional hospital. All CTAs were assessed by the automated algorithm. Consensus reads by 2 neuroradiologists served as the reference standard. ROC analysis was used to assess diagnostic performance of the algorithm for detection of (1) anterior circulation LVOs involving the intracranial internal carotid artery or M1 segment middle cerebral artery (M1-MCA); (2) anterior circulation LVOs and proximal M2 segment MCA (M2-MCA) occlusions; and (3) individual segment occlusions. Results- CTAs from 926 patients (median age 70 years, interquartile range: 58-80; 422 females) were analyzed. Three hundred ninety-five patients had an anterior circulation LVO or M2-MCA occlusion (National Institutes of Health Stroke Scale 14 [median], interquartile range: 9-19). Sensitivity and specificity were 97% and 74%, respectively, for LVO detection, and 95% and 79%, respectively, when M2 occlusions were included. On analysis by occlusion site, sensitivities were 90% (M2-MCA), 97% (M1-MCA), and 97% (intracranial internal carotid artery) with corresponding area-under-the-ROC-curves of 0.874 (M2), 0.962 (M1), and 0.997 (intracranial internal carotid artery). Conclusions- Intracranial anterior circulation LVOs and proximal M2 occlusions can be rapidly and reliably detected by an automated detection tool, which may facilitate intra- and inter-instutional workflows and emergent imaging triage in the care of patients with stroke.

  View details for DOI 10.1161/STROKEAHA.119.027076

  View details for PubMedID 31679501

• A dual-tuned <SUP>17</SUP>O/<SUP>1</SUP>H head array for direct brain oximetry at 3 Tesla MAGNETIC RESONANCE IN MEDICINE Lakshmanan, K., Dehkharghani, S., Madelin, G., Brown, R. 2020; 83 (4): 1512-1518

  Abstract

  To design and build a dual-tuned 17 O/1 H coil for direct brain oximetry at 3T.A dual-tuned 17 O/1 H coil comprising 2 degenerate mode birdcage coils was constructed to facilitate high-sensitivity 17 O and 1 H imaging. In vivo 17 O brain images were acquired in a healthy volunteer using a fermat looped orthogonally encoded trajectories sequence, together with high-resolution structural brain 1 H images.Natural abundance 17 O images with a nominal resolution of 8 mm3 were acquired in under 20 minutes exhibiting clear delineation of the physiological 17 O distribution. One-millimeter isotropic 1 H structural brain images demonstrated excellent quality and anatomical detail using routine clinical imaging sequence parameters and parallel acceleration.A dual-tuned 17 O/1 H array was constructed to enable high-sensitivity 17 O and 1 H imaging under standard clinical 3 T scanning conditions.

  View details for DOI 10.1002/mrm.28005

  View details for Web of Science ID 000489237500001

  View details for PubMedID 31593372

  View details for PubMedCentralID PMC6949369

• Automated Detection of Intracranial Large Vessel Occlusions on Computed Tomography Angiography. Stroke Amukotuwa, S. A., Straka, M., Smith, H., Chandra, R. V., Dehkharghani, S., Fischbein, N. J., Bammer, R. 2019: STROKEAHA119026259

  Abstract

  Background and Purpose- Endovascular thrombectomy is highly effective in acute ischemic stroke patients with an anterior circulation large vessel occlusion (LVO), decreasing morbidity and mortality. Accurate and prompt identification of LVOs is imperative because these patients have large volumes of tissue that are at risk of infarction without timely reperfusion, and the treatment window is limited to 24 hours. We assessed the accuracy and speed of a commercially available fully automated LVO-detection tool in a cohort of patients presenting to a regional hospital with suspected stroke. Methods- Consecutive patients who underwent multimodal computed tomography with thin-slice computed tomography angiography between January 1, 2017 and December 31, 2018 for suspected acute ischemic stroke within 24 hours of onset were retrospectively identified. The multimodal computed tomographies were assessed by 2 neuroradiologists in consensus for the presence of an intracranial anterior circulation LVO or M2-segment middle cerebral artery occlusion (the reference standard). The patients' computed tomography angiographies were then processed using an automated LVO-detection algorithm (RAPID CTA). Receiver-operating characteristic analysis was used to determine sensitivity, specificity, and negative predictive value of the algorithm for detection of (1) an LVO and (2) either an LVO or M2-segment middle cerebral artery occlusion. Results- CTAs from 477 patients were analyzed (271 men and 206 women; median age, 71; IQR, 60-80). Median processing time was 158 seconds (IQR, 150-167 seconds). Seventy-eight patients had an anterior circulation LVO, and 28 had an isolated M2-segment middle cerebral artery occlusion. The sensitivity, negative predictive value, and specificity were 0.94, 0.98, and 0.76, respectively for detection of an intracranial LVO and 0.92, 0.97, and 0.81, respectively for detection of either an intracranial LVO or M2-segment middle cerebral artery occlusion. Conclusions- The fully automated algorithm had very high sensitivity and negative predictive value for LVO detection with fast processing times, suggesting that it can be used in the emergent setting as a screening tool to alert radiologists and expedite formal diagnosis.

  View details for DOI 10.1161/STROKEAHA.119.026259

  View details for PubMedID 31495328

• Radiological Management of Angiographically Negative, Spontaneous Intracranial Subarachnoid Hemorrhage: A Multicenter Study of Utilization and Diagnostic Yield NEUROSURGERY Sadigh, G., Menon, R. K., Bhojak, M., Aladi, A., Mossa-Basha, M., Wu, L., Lehman, V. T., Brinjikji, W., Dehkharghani, S., Derakhshani, A., Mossa-Basha, F., Allen, J. W. 2019; 85 (1): 126-133

  Abstract

  The optimal diagnostic evaluation for patients with angiographically negative subarachnoid hemorrhage (AN-SAH) remains controversial.To assess the utilization rate and diagnostic yield of imaging tests routinely obtained in identifying a structural cause for AN-SAH.In this retrospective multicenter study, consecutive adult patients admitted with nontraumatic, AN-SAH between 01/2010 and 12/2015 were included. Patients with intraparenchymal, subdural, or epidural hematomas in addition to SAH were excluded. Outcomes studied included utilization rate, diagnostic yield, and median time from admission for the following imaging tests: initial computed tomography angiography (CTA) and digital subtraction angiography (DSA), brain and cervical spine magnetic resonance imaging (MRI), and any repeat DSA or CTA performed either during initial admission or at long-term follow-up.A total of 752 patients were included (mean age, 53 yr; 54% male). Initial CTA and DSA were performed in 89% and 100% of patients, respectively. Brain MRI was performed in 75% of patients and was positive in 0.7% of cases. Cervical spine MRI was performed in 61% of patients and was positive in 0.2% of cases. Repeat, same-admission follow-up DSA and CTA were performed in 48% and 51% of patients and were positive in 3.3% and 1% of cases, respectively. Delayed follow-up DSA and CTA after discharge were performed in 26% and 7% of patients and were positive in 2% and 3.7% of cases, respectively, all with negative prior imaging studies.Cervical spine and brain MRI have extremely low diagnostic yield, both are commonly utilized in patients with AN-SAH; while repeat DSA and CTA are utilized less commonly and have slightly higher diagnostic yield.

  View details for DOI 10.1093/neuros/nyy225

  View details for Web of Science ID 000484356700033

  View details for PubMedID 29850838

• Cerebral MR oximetry during acetazolamide augmentation: Beyond cerebrovascular reactivity in hemodynamic failure JOURNAL OF MAGNETIC RESONANCE IMAGING Leatherday, C., Dehkharghani, S., Nahab, F., Allen, J. W., Wu, J., Hu, R., Qiu, D. 2019; 50 (1): 175-182

  Abstract

  Oxygen extraction fraction (OEF) elevation predicts increased ischemic stroke incidence among patients with carotid steno-occlusive disease, and can be estimated from quantitative susceptibility mapping (QSM) MRI.To explore QSM oximetry during acetazolamide (ACZ) challenge, hypothesizing that detectable OEF alterations will reflect hemodynamic compromise in unilateral cerebrovascular disease (CVD) patients.Retrospective.Fourteen unilateral CVD patients, and 24 healthy controls (HC).Multiecho gradient echo (GRE) and T1 -weighted images at 3T.We constructed QSM images and R2* maps from multiecho GRE images. QSM-OEF maps were generated from the susceptibility difference between venous blood and background brain tissue. Intrasubject diseased/contralateral hemisphere OEF ratios in the middle cerebral artery (MCA) territories were calculated. Intravascular susceptibility in the straight sinus (SS) and MCA was also measured.The result significance was determined using t-tests and Pearson's correlation.Mean and standard deviation for the patient diseased/contralateral OEF ratios were 1.15 ± 0.14 at baseline and 1.23 ± 0.17 post-ACZ. Disease group R2* ratios were 0.95 ± 0.05 at baseline and 1.03 ± 0.08 post-ACZ. Left/right OEF and R2* ratios for the HC group were 0.98 ± 0.06 and 0.99 ± 0.038, respectively. Susceptibility (ppb) in the SS and MCA in patients was 162.63 ± 35.4 and -22.33 ± 13.70, respectively, at baseline, 124.56 ± 37.43 and -19.27 ± 23.14 post-ACZ. The HC group SS and MCA susceptibility was 146.10 ± 24.79 and -19.59 ± 12.37, respectively. Patient group OEF ratios were greater than 1.0 before and after ACZ challenge (P < 0.01 and < 0.001, respectively, one-sample t-test), and were greater than HC ratios (P < 0.001 unpaired t-test). OEF and R2* ratios increased from baseline to post-ACZ (P = 0.024, 0.004, respectively, paired t-test). Detectable blood oxygenation change was confirmed by finding SS susceptibility decreased from baseline to post-ACZ (P < 0.001, paired t-test), while MCA susceptibility did not change significantly (P = 0.67, paired t-test).These results suggest QSM is sensitive to dynamic OEF modulation during hemodynamic augmentation.3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:175-182.

  View details for DOI 10.1002/jmri.26546

  View details for Web of Science ID 000471831600017

  View details for PubMedID 30390367

• eTICI reperfusion: defining success in endovascular stroke therapy JOURNAL OF NEUROINTERVENTIONAL SURGERY Liebeskind, D. S., Bracard, S., Guillemin, F., Jahan, R., Jovin, T. G., Majoie, C. M., Mitchell, P. J., van der Lugt, A., Menon, B. K., San Roman, L., Campbell, B. C. V., Muir, K. W., Hill, M. D., Dippel, D. W. J., Saver, J. L., Demchuk, A. M., Davalos, A., White, P., Brown, S., Goyal, M., HERMES Collaborators 2019; 11 (5): 433-+

  Abstract

  Revascularization after endovascular therapy for acute ischemic stroke is measured by the Thrombolysis In Cerebral Infarction (TICI) scale, yet variability exists in scale definitions. We examined the degree of reperfusion with the expanded TICI (eTICI) scale and association with outcomes in the HERMES collaboration of recent endovascular trials.The HERMES Imaging Core, blind to all other data, evaluated angiography after endovascular therapy in HERMES. A battery of TICI scores (mTICI, TICI, TICI2C) was used to define reperfusion of the initial target occlusion defined by non-invasive imaging and conventional angiography.Angiography of 801 subjects was available, including 797 defined by non-invasive imaging (154 internal carotid artery (ICA), 583 M1, 60 M2) and 748 by conventional angiography (195 ICA, 459 M1, 94 M2). Among 729 subjects in whom the reperfusion grade could be established, using eTICI (3=100%, 2C=90-99%, 2b67=67-89%, 2b50=50-66%) of the conventional angiography target occlusion, there were 63 eTICI 3 (9%), 166 eTICI 2c (23%), 218 eTICI 2b67 (30%), 103 eTICI 2b50 (14%), 100 eTICI 2a (14%), 19 eTICI 1 (3%), and 60 eTICI 0 (8%). Modified Rankin Scale shift analyses from baseline to 90 days showed that increasing TICI grades were linked with better outcomes, with significant distinctions between TICI 0/1 versus 2a (p=0.028), 2a versus 2b50 (p=0.017), and 2b50 versus 2b67 (p=0.014).The benefit of endovascular therapy in HERMES was strongly associated with increasing degrees of reperfusion defined by eTICI. The eTICI metric identified meaningful distinctions in clinical outcomes and may be used in future studies and routine practice.

  View details for DOI 10.1136/neurintsurg-2018-014127

  View details for Web of Science ID 000471844900003

  View details for PubMedID 30194109

• Penumbral imaging and functional outcome in patients with anterior circulation ischaemic stroke treated with endovascular thrombectomy versus medical therapy: a meta-analysis of individual patient-level data LANCET NEUROLOGY Campbell, B. C. V., Majoie, C. M., Albers, G. W., Menon, B. K., Yassi, N., Sharma, G., van Zwam, W. H., van Oostenbrugge, R. J., Demchuk, A. M., Guillemin, F., White, P., Davalos, A., van der Lugt, A., Butcher, K. S., Cherifi, A., Marquering, H. A., Cloud, G., Macho Fernandez, J. M., Madigan, J., Oppenheim, C., Donnan, G. A., Roos, Y. M., Shankar, J., Lingsma, H., Bonafe, A., Raoult, H., Hernandez-Perez, M., Bharatha, A., Jahan, R., Jansen, O., Richard, S., Levy, E. I., Berkhemer, O. A., Soudant, M., Aja, L., Davis, S. M., Krings, T., Tisserand, M., San Roman, L., Tomasello, A., Beumer, D., Brown, S., Liebeskind, D. S., Bracard, S., Muir, K. W., Dippel, D. W. J., Goyal, M., Saver, J. L., Jovin, T. G., Hill, M. D., Mitchell, P. J., HERMES Collaborators 2019; 18 (1): 46–55

  View details for DOI 10.1016/S1474-4422(18)30314-4

  View details for Web of Science ID 000453007700022

• Penumbral imaging and functional outcome in patients with anterior circulation ischaemic stroke treated with endovascular thrombectomy versus medical therapy: a meta-analysis of individual patient-level data. The Lancet. Neurology Campbell, B. C., Majoie, C. B., Albers, G. W., Menon, B. K., Yassi, N., Sharma, G., van Zwam, W. H., van Oostenbrugge, R. J., Demchuk, A. M., Guillemin, F., White, P., Davalos, A., van der Lugt, A., Butcher, K. S., Cherifi, A., Marquering, H. A., Cloud, G., Macho Fernandez, J. M., Madigan, J., Oppenheim, C., Donnan, G. A., Roos, Y. B., Shankar, J., Lingsma, H., Bonafe, A., Raoult, H., Hernandez-Perez, M., Bharatha, A., Jahan, R., Jansen, O., Richard, S., Levy, E. I., Berkhemer, O. A., Soudant, M., Aja, L., Davis, S. M., Krings, T., Tisserand, M., San Roman, L., Tomasello, A., Beumer, D., Brown, S., Liebeskind, D. S., Bracard, S., Muir, K. W., Dippel, D. W., Goyal, M., Saver, J. L., Jovin, T. G., Hill, M. D., Mitchell, P. J., HERMES collaborators, Berkhemer, O. A., Fransen, P. S., Beumer, D., van den Berg, L. A., Lingsma, H. F., Yoo, A. J., Schonewille, W. J., Vos, J. A., Nederkoorn, P. J., Wermer, M. J., van Walderveen, M. A., Staals, J., Hofmeijer, J., van Oostayen, J. A., Lycklama A Nijeholt, G. J., Boiten, J., Brouwer, P. A., Emmer, B. J., de Bruijn, S. F., van Dijk, L. C., Kappelle, J., Lo, R. H., van Dijk, E. J., de Vries, J., de Kort, P. L., van Rooij, W. J., van den Berg, J. S., van Hasselt, B. A., Aerden, L. A., Dallinga, R. J., Visser, M. C., Bot, J. C., Vroomen, P. C., Eshghi, O., Schreuder, T. H., Heijboer, R. J., Keizer, K., Tielbeek, A. V., den Hertog, H. M., Gerrits, D. G., van den Berg-Vos, R. M., Karas, G. B., Steyerberg, E. W., Flach, Z., Marquering, H. A., Sprengers, M. E., Jenniskens, S. F., Beenen, L. F., van den Berg, R., Koudstaal, P. J., van Zwam, W. H., Roos, Y. B., van der Lugt, A., van Oostenbrugge, R. J., Majoie, C. B., Dippel, D. W., Brown, M. M., Liebig, T., Stijnen, T., Andersson, T., Mattle, H., Wahlgren, N., van der Heijden, E., Ghannouti, N., Fleitour, N., Hooijenga, I., Puppels, C., Pellikaan, W., Geerling, A., Lindl-Velema, A., van Vemde, G., de Ridder, A., Greebe, P., de Bont-Stikkelbroeck, J., de Meris, J., Janssen, K., Struijk, W., Licher, S., Boodt, N., Ros, A., Venema, E., Slokkers, I., Ganpat, R., Mulder, M., Saiedie, N., Heshmatollah, A., Schipperen, S., Vinken, S., van Boxtel, T., Koets, J., Boers, M., Santos, E., Borst, J., Jansen, I., Kappelhof, M., Lucas, M., Geuskens, R., Barros, R. S., Dobbe, R., Csizmadia, M., Hill, M. D., Goyal, M., Demchuk, A. M., Menon, B. K., Eesa, M., Ryckborst, K. J., Wright, M. R., Kamal, N. R., Andersen, L., Randhawa, P. A., Stewart, T., Patil, S., Minhas, P., Almekhlafi, M., Mishra, S., Clement, F., Sajobi, T., Shuaib, A., Montanera, W. J., Roy, D., Silver, F. L., Jovin, T. G., Frei, D. F., Sapkota, B., Rempel, J. L., Thornton, J., Williams, D., Tampieri, D., Poppe, A. Y., Dowlatshahi, D., Wong, J. H., Mitha, A. P., Subramaniam, S., Hull, G., Lowerison, M. W., Sajobi, T., Salluzzi, M., Wright, M. R., Maxwell, M., Lacusta, S., Drupals, E., Armitage, K., Barber, P. A., Smith, E. E., Morrish, W. F., Coutts, S. B., Derdeyn, C., Demaerschalk, B., Yavagal, D., Martin, R., Brant, R., Yu, Y., Willinsky, R. A., Montanera, W. J., Weill, A., Kenney, C., Aram, H., Stewart, T., Stys, P. K., Watson, T. W., Klein, G., Pearson, D., Couillard, P., Trivedi, A., Singh, D., Klourfeld, E., Imoukhuede, O., Nikneshan, D., Blayney, S., Reddy, R., Choi, P., Horton, M., Musuka, T., Dubuc, V., Field, T. S., Desai, J., Adatia, S., Alseraya, A., Nambiar, V., van Dijk, R., Wong, J. H., Mitha, A. P., Morrish, W. F., Eesa, M., Newcommon, N. J., Shuaib, A., Schwindt, B., Butcher, K. S., Jeerakathil, T., Buck, B., Khan, K., Naik, S. S., Emery, D. J., Owen, R. J., Kotylak, T. B., Ashforth, R. A., Yeo, T. A., McNally, D., Siddiqui, M., Saqqur, M., Hussain, D., Kalashyan, H., Manosalva, A., Kate, M., Gioia, L., Hasan, S., Mohammad, A., Muratoglu, M., Williams, D., Thornton, J., Cullen, A., Brennan, P., O'Hare, A., Looby, S., Hyland, D., Duff, S., McCusker, M., Hallinan, B., Lee, S., McCormack, J., Moore, A., O'Connor, M., Donegan, C., Brewer, L., Martin, A., Murphy, S., O'Rourke, K., Smyth, S., Kelly, P., Lynch, T., Daly, T., O'Brien, P., O'Driscoll, A., Martin, M., Daly, T., Collins, R., Coughlan, T., McCabe, D., Murphy, S., O'Neill, D., Mulroy, M., Lynch, O., Walsh, T., O'Donnell, M., Galvin, T., Harbison, J., McElwaine, P., Mulpeter, K., McLoughlin, C., Reardon, M., Harkin, E., Dolan, E., Watts, M., Cunningham, N., Fallon, C., Gallagher, S., Cotter, P., Crowe, M., Doyle, R., Noone, I., Lapierre, M., Cote, V. A., Lanthier, S., Odier, C., Durocher, A., Raymond, J., Weill, A., Daneault, N., Deschaintre, Y., Jankowitz, B., Baxendell, L., Massaro, L., Jackson-Graves, C., Decesare, S., Porter, P., Armbruster, K., Adams, A., Billigan, J., Oakley, J., Ducruet, A., Jadhav, A., Giurgiutiu, D., Aghaebrahim, A., Reddy, V., Hammer, M., Starr, M., Totoraitis, V., Wechsler, L., Streib, S., Rangaraju, S., Campbell, D., Rocha, M., Gulati, D., Silver, F. L., Krings, T., Kalman, L., Cayley, A., Williams, J., Stewart, T., Wiegner, R., Casaubon, L. K., Jaigobin, C., Del Campo, J. M., Elamin, E., Schaafsma, J. D., Willinsky, R. A., Agid, R., Farb, R., Ter Brugge, K., Sapkoda, B. L., Baxter, B. W., Barton, K., Knox, A., Porter, A., Sirelkhatim, A., Devlin, T., Dellinger, C., Pitiyanuvath, N., Patterson, J., Nichols, J., Quarfordt, S., Calvert, J., Hawk, H., Fanale, C., Frei, D. F., Bitner, A., Novak, A., Huddle, D., Bellon, R., Loy, D., Wagner, J., Chang, I., Lampe, E., Spencer, B., Pratt, R., Bartt, R., Shine, S., Dooley, G., Nguyen, T., Whaley, M., McCarthy, K., Teitelbaum, J., Tampieri, D., Poon, W., Campbell, N., Cortes, M., Dowlatshahi, D., Lum, C., Shamloul, R., Robert, S., Stotts, G., Shamy, M., Steffenhagen, N., Blacquiere, D., Hogan, M., AlHazzaa, M., Basir, G., Lesiuk, H., Iancu, D., Santos, M., Choe, H., Weisman, D. C., Jonczak, K., Blue-Schaller, A., Shah, Q., MacKenzie, L., Klein, B., Kulandaivel, K., Kozak, O., Gzesh, D. J., Harris, L. J., Khoury, J. S., Mandzia, J., Pelz, D., Crann, S., Fleming, L., Hesser, K., Beauchamp, B., Amato-Marzialli, B., Boulton, M., Lopez-Ojeda, P., Sharma, M., Lownie, S., Chan, R., Swartz, R., Howard, P., Golob, D., Gladstone, D., Boyle, K., Boulos, M., Hopyan, J., Yang, V., Da Costa, L., Holmstedt, C. A., Turk, A. S., Navarro, R., Jauch, E., Ozark, S., Turner, R., Phillips, S., Shankar, J., Jarrett, J., Gubitz, G., Maloney, W., Vandorpe, R., Schmidt, M., Heidenreich, J., Hunter, G., Kelly, M., Whelan, R., Peeling, L., Burns, P. A., Hunter, A., Wiggam, I., Kerr, E., Watt, M., Fulton, A., Gordon, P., Rennie, I., Flynn, P., Smyth, G., O'Leary, S., Gentile, N., Linares, G., McNelis, P., Erkmen, K., Katz, P., Azizi, A., Weaver, M., Jungreis, C., Faro, S., Shah, P., Reimer, H., Kalugdan, V., Saposnik, G., Bharatha, A., Li, Y., Kostyrko, P., Santos, M., Marotta, T., Montanera, W., Sarma, D., Selchen, D., Spears, J., Heo, J. H., Jeong, K., Kim, D. J., Kim, B. M., Kim, Y. D., Song, D., Lee, K., Yoo, J., Bang, O. Y., Rho, S., Lee, J., Jeon, P., Kim, K. H., Cha, J., Kim, S. J., Ryoo, S., Lee, M. J., Sohn, S., Kim, C., Ryu, H., Hong, J., Chang, H., Lee, C., Rha, J., Davis, S. M., Donnan, G. A., Campbell, B. C., Mitchell, P. J., Churilov, L., Yan, B., Dowling, R., Yassi, N., Oxley, T. J., Wu, T. Y., Silver, G., McDonald, A., McCoy, R., Kleinig, T. J., Scroop, R., Dewey, H. M., Simpson, M., Brooks, M., Coulton, B., Krause, M., Harrington, T. J., Steinfort, B., Faulder, K., Priglinger, M., Day, S., Phan, T., Chong, W., Holt, M., Chandra, R. V., Ma, H., Young, D., Wong, K., Wijeratne, T., Tu, H., Mackay, E., Celestino, S., Bladin, C. F., Loh, P. S., Gilligan, A., Ross, Z., Coote, S., Frost, T., Parsons, M. W., Miteff, F., Levi, C. R., Ang, T., Spratt, N., Kaauwai, L., Badve, M., Rice, H., de Villiers, L., Barber, P. A., McGuinness, B., Hope, A., Moriarty, M., Bennett, P., Wong, A., Coulthard, A., Lee, A., Jannes, J., Field, D., Sharma, G., Salinas, S., Cowley, E., Snow, B., Kolbe, J., Stark, R., King, J., Macdonnell, R., Attia, J., D'Este, C., Saver, J. L., Goyal, M., Diener, H. C., Levy, E. I., Bonafe, A., Mendes Pereira, V., Jahan, R., Albers, G. W., Cognard, C., Cohen, D. J., Hacke, W., Jansen, O., Jovin, T. G., Mattle, H. P., Nogueira, R. G., Siddiqui, A. H., Yavagal, D. R., von Kummer, R., Smith, W., Turjman, F., Hamilton, S., Chiacchierini, R., Amar, A., Sanossian, N., Loh, Y., Devlin, T., Baxter, B., Hawk, H., Sapkota, B., Quarfordt, S., Sirelkhatim, A., Dellinger, C., Barton, K., Reddy, V. K., Ducruet, A., Jadhav, A., Horev, A., Giurgiutiu, D., Totoraitis, V., Hammer, M., Jankowitz, B., Wechsler, L., Rocha, M., Gulati, D., Campbell, D., Star, M., Baxendell, L., Oakley, J., Siddiqui, A., Hopkins, L. N., Snyder, K., Sawyer, R., Hall, S., Costalat, V., Riquelme, C., Machi, P., Omer, E., Arquizan, C., Mourand, I., Charif, M., Ayrignac, X., Menjot de Champfleur, N., Leboucq, N., Gascou, G., Moynier, M., du Mesnil de Rochemont, R., Singer, O., Berkefeld, J., Foerch, C., Lorenz, M., Pfeilschifer, W., Hattingen, E., Wagner, M., You, S. J., Lescher, S., Braun, H., Dehkharghani, S., Belagaje, S. R., Anderson, A., Lima, A., Obideen, M., Haussen, D., Dharia, R., Frankel, M., Patel, V., Owada, K., Saad, A., Amerson, L., Horn, C., Doppelheuer, S., Schindler, K., Lopes, D. K., Chen, M., Moftakhar, R., Anton, C., Smreczak, M., Carpenter, J. S., Boo, S., Rai, A., Roberts, T., Tarabishy, A., Gutmann, L., Brooks, C., Brick, J., Domico, J., Reimann, G., Hinrichs, K., Becker, M., Heiss, E., Selle, C., Witteler, A., Al Boutros, S., Danch, M., Ranft, A., Rohde, S., Burg, K., Weimar, C., Zegarac, V., Hartmann, C., Schlamann, M., Goricke, S., Ringlestein, A., Wanke, I., Monninghoff, C., Dietzold, M., Budzik, R., Davis, T., Eubank, G., Hicks, W. J., Pema, P., Vora, N., Mejilla, J., Taylor, M., Clark, W., Rontal, A., Fields, J., Peterson, B., Nesbit, G., Lutsep, H., Bozorgchami, H., Priest, R., Ologuntoye, O., Barnwell, S., Dogan, A., Herrick, K., Takahasi, C., Beadell, N., Brown, B., Jamieson, S., Hussain, M. S., Russman, A., Hui, F., Wisco, D., Uchino, K., Khawaja, Z., Katzan, I., Toth, G., Cheng Ching, E., Bain, M., Man, S., Farrag, A., George, P., John, S., Shankar, L., Drofa, A., Dahlgren, R., Bauer, A., Itreat, A., Taqui, A., Cerejo, R., Richmond, A., Ringleb, P., Bendszus, M., Mohlenbruch, M., Reiff, T., Amiri, H., Purrucker, J., Herweh, C., Pham, M., Menn, O., Ludwig, I., Acosta, I., Villar, C., Morgan, W., Sombutmai, C., Hellinger, F., Allen, E., Bellew, M., Gandhi, R., Bonwit, E., Aly, J., Ecker, R. D., Seder, D., Morris, J., Skaletsky, M., Belden, J., Baker, C., Connolly, L. S., Papanagiotou, P., Roth, C., Kastrup, A., Politi, M., Brunner, F., Alexandrou, M., Merdivan, H., Ramsey, C., Given Ii, C., Renfrow, S., Deshmukh, V., Sasadeusz, K., Vincent, F., Thiesing, J. T., Putnam, J., Bhatt, A., Kansara, A., Caceves, D., Lowenkopf, T., Yanase, L., Zurasky, J., Dancer, S., Freeman, B., Scheibe Mirek, T., Robison, J., Rontal, A., Roll, J., Clark, D., Rodriguez, M., Fitzsimmons, B., Zaidat, O., Lynch, J. R., Lazzaro, M., Larson, T., Padmore, L., Das, E., Farrow Schmidt, A., Hassan, A., Tekle, W., Cate, C., Jansen, O., Cnyrim, C., Wodarg, F., Wiese, C., Binder, A., Riedel, C., Rohr, A., Lang, N., Laufs, H., Krieter, S., Remonda, L., Diepers, M., Anon, J., Nedeltchev, K., Kahles, T., Biethahn, S., Lindner, M., Chang, V., Gachter, C., Esperon, C., Guglielmetti, M., Arenillas Lara, J. F., Martinez Galdamez, M., Calleja Sanz, A. I., Cortijo Garcia, E., Garcia Bermejo, P., Perez, S., Mulero Carrillo, P., Crespo Vallejo, E., Ruiz Pinero, M., Lopez Mesonero, L., Reyes Munoz, F. J., Brekenfeld, C., Buhk, J., Krutzelmann, A., Thomalla, G., Cheng, B., Beck, C., Hoppe, J., Goebell, E., Holst, B., Grzyska, U., Wortmann, G., Starkman, S., Duckwiler, G., Jahan, R., Rao, N., Sheth, S., Ng, K., Noorian, A., Szeder, V., Nour, M., McManus, M., Huang, J., Tarpley, J., Tateshima, S., Gonzalez, N., Ali, L., Liebeskind, D., Hinman, J., Calderon Arnulphi, M., Liang, C., Guzy, J., Koch, S., DeSousa, K., Gordon Perue, G., Haussen, D., Elhammady, M., Peterson, E., Pandey, V., Dharmadhikari, S., Khandelwal, P., Malik, A., Pafford, R., Gonzalez, P., Ramdas, K., Andersen, G., Damgaard, D., Von Weitzel Mudersbach, P., Simonsen, C., Ruiz de Morales Ayudarte, N., Poulsen, M., Sorensen, L., Karabegovich, S., Hjorringgaard, M., Hjort, N., Harbo, T., Sorensen, K., Deshaies, E., Padalino, D., Swarnkar, A., Latorre, J. G., Elnour, E., El Zammar, Z., Villwock, M., Farid, H., Balgude, A., Cross, L., Hansen, K., Holtmannspotter, M., Kondziella, D., Hoejgaard, J., Taudorf, S., Soendergaard, H., Wagner, A., Cronquist, M., Stavngaard, T., Cortsen, M., Krarup, L. H., Hyldal, T., Haring, H., Guggenberger, S., Hamberger, M., Trenkler, J., Sonnberger, M., Nussbaumer, K., Dominger, C., Bach, E., Jagadeesan, B. D., Taylor, R., Kim, J., Shea, K., Tummala, R., Zacharatos, H., Sandhu, D., Ezzeddine, M., Grande, A., Hildebrandt, D., Miller, K., Scherber, J., Hendrickson, A., Jumaa, M., Zaidi, S., Hendrickson, T., Snyder, V., Killer Oberpfalzer, M., Mutzenbach, J., Weymayr, F., Broussalis, E., Stadler, K., Jedlitschka, A., Malek, A., Mueller Kronast, N., Beck, P., Martin, C., Summers, D., Day, J., Bettinger, I., Holloway, W., Olds, K., Arkin, S., Akhtar, N., Boutwell, C., Crandall, S., Schwartzman, M., Weinstein, C., Brion, B., Prothmann, S., Kleine, J., Kreiser, K., Boeckh Behrens, T., Poppert, H., Wunderlich, S., Koch, M. L., Biberacher, V., Huberle, A., Gora Stahlberg, G., Knier, B., Meindl, T., Utpadel Fischler, D., Zech, M., Kowarik, M., Seifert, C., Schwaiger, B., Puri, A., Hou, S., Wakhloo, A., Moonis, M., Henniger, N., Goddeau, R., Massari, F., Minaeian, A., Lozano, J. D., Ramzan, M., Stout, C., Patel, A., Tunguturi, A., Onteddu, S., Carandang, R., Howk, M., Ribo, M., Sanjuan, E., Rubiera, M., Pagola, J., Flores, A., Muchada, M., Meler, P., Huerga, E., Gelabert, S., Coscojuela, P., Tomasello, A., Rodriguez, D., Santamarina, E., Maisterra, O., Boned, S., Sero, L., Rovira, A., Molina, C. A., Millan, M., Munoz, L., Perez de la Ossa, N., Gomis, M., Dorado, L., Lopez-Cancio, E., Palomeras, E., Munuera, J., Garcia Bermejo, P., Remollo, S., Castano, C., Garcia-Sort, R., Cuadras, P., Puyalto, P., Hernandez-Perez, M., Jimenez, M., Martinez-Pineiro, A., Lucente, G., Davalos, A., Chamorro, A., Urra, X., Obach, V., Cervera, A., Amaro, S., Llull, L., Codas, J., Balasa, M., Navarro, J., Arino, H., Aceituno, A., Rudilosso, S., Renu, A., Macho, J. M., San Roman, L., Blasco, J., Lopez, A., Macias, N., Cardona, P., Quesada, H., Rubio, F., Cano, L., Lara, B., de Miquel, M. A., Aja, L., Serena, J., Cobo, E., Albers, G. W., Lees, K. R., Arenillas, J., Roberts, R., Minhas, P., Al-Ajlan, F., Salluzzi, M., Zimmel, L., Patel, S., Eesa, M., Marti-Fabregas, J., Jankowitz, B., Serena, J., Salvat-Plana, M., Lopez-Cancio, E., Bracard, S., Ducrocq, X., Anxionnat, R., Baillot, P., Barbier, C., Derelle, A., Lacour, J., Richard, S., Samson, Y., Sourour, N., Baronnet-Chauvet, F., Clarencon, F., Crozier, S., Deltour, S., Di Maria, F., Le Bouc, R., Leger, A., Mutlu, G., Rosso, C., Szatmary, Z., Yger, M., Zavanone, C., Bakchine, S., Pierot, L., Caucheteux, N., Estrade, L., Kadziolka, K., Leautaud, A., Renkes, C., Serre, I., Desal, H., Guillon, B., Boutoleau-Bretonniere, C., Daumas-Duport, B., De Gaalon, S., Derkinderen, P., Evain, S., Herisson, F., Laplaud, D., Lebouvier, T., Lintia-Gaultier, A., Pouclet-Courtemanche, H., Rouaud, T., Rouaud Jaffrenou, V., Schunck, A., Sevin-Allouet, M., Toulgoat, F., Wiertlewski, S., Gauvrit, J., Ronziere, T., Cahagne, V., Ferre, J., Pinel, J., Raoult, H., Mas, J., Meder, J., Al Najjar-Carpentier, A., Birchenall, J., Bodiguel, E., Calvet, D., Domigo, V., Godon-Hardy, S., Guiraud, V., Lamy, C., Majhadi, L., Morin, L., Naggara, O., Trystram, D., Turc, G., Berge, J., Sibon, I., Menegon, P., Barreau, X., Rouanet, F., Debruxelles, S., Kazadi, A., Renou, P., Fleury, O., Pasco-Papon, A., Dubas, F., Caroff, J., Godard Ducceschi, S., Hamon, M., Lecluse, A., Marc, G., Giroud, M., Ricolfi, F., Bejot, Y., Chavent, A., Gentil, A., Kazemi, A., Osseby, G., Voguet, C., Mahagne, M., Sedat, J., Chau, Y., Suissa, L., Lachaud, S., Houdart, E., Stapf, C., Buffon Porcher, F., Chabriat, H., Guedin, P., Herve, D., Jouvent, E., Mawet, J., Saint-Maurice, J., Schneble, H., Turjman, F., Nighoghossian, N., Berhoune, N., Bouhour, F., Cho, T., Derex, L., Felix, S., Gervais-Bernard, H., Gory, B., Manera, L., Mechtouff, L., Ritzenthaler, T., Riva, R., Salaris Silvio, F., Tilikete, C., Blanc, R., Obadia, M., Bartolini, M. B., Gueguen, A., Piotin, M., Pistocchi, S., Redjem, H., Drouineau, J., Neau, J., Godeneche, G., Lamy, M., Marsac, E., Velasco, S., Clavelou, P., Chabert, E., Bourgois, N., Cornut-Chauvinc, C., Ferrier, A., Gabrillargues, J., Jean, B., Marques, A., Vitello, N., Detante, O., Barbieux, M., Boubagra, K., Favre Wiki, I., Garambois, K., Tahon, F., Ashok, V., Voguet, C., Coskun, O., Guedin, P., Rodesch, G., Lapergue, B., Bourdain, F., Evrard, S., Graveleau, P., Decroix, J. P., Wang, A., Sellal, F., Ahle, G., Carelli, G., Dugay, M., Gaultier, C., Lebedinsky, A. P., Lita, L., Musacchio, R. M., Renglewicz-Destuynder, C., Tournade, A., Vuillemet, F., Montoro, F. M., Mounayer, C., Faugeras, F., Gimenez, L., Labach, C., Lautrette, G., Denier, C., Saliou, G., Chassin, O., Dussaule, C., Melki, E., Ozanne, A., Puccinelli, F., Sachet, M., Sarov, M., Bonneville, J., Moulin, T., Biondi, A., De Bustos Medeiros, E., Vuillier, F., Courtheoux, P., Viader, F., Apoil-Brissard, M., Bataille, M., Bonnet, A., Cogez, J., Kazemi, A., Touze, E., Leclerc, X., Leys, D., Aggour, M., Aguettaz, P., Bodenant, M., Cordonnier, C., Deplanque, D., Girot, M., Henon, H., Kalsoum, E., Lucas, C., Pruvo, J., Zuniga, P., Bonafe, A., Arquizan, C., Costalat, V., Machi, P., Mourand, I., Riquelme, C., Bounolleau, P., Arteaga, C., Faivre, A., Bintner, M., Tournebize, P., Charlin, C., Darcel, F., Gauthier-Lasalarie, P., Jeremenko, M., Mouton, S., Zerlauth, J., Lamy, C., Herve, D., Hassan, H., Gaston, A., Barral, F., Garnier, P., Beaujeux, R., Wolff, V., Herbreteau, D., Debiais, S., Murray, A., Ford, G., Muir, K. W., White, P., Brown, M. M., Clifton, A., Freeman, J., Ford, I., Markus, H., Wardlaw, J., Lees, K. R., Molyneux, A., Robinson, T., Lewis, S., Norrie, J., Robertson, F., Perry, R., Dixit, A., Cloud, G., Clifton, A., Madigan, J., Roffe, C., Nayak, S., Lobotesis, K., Smith, C., Herwadkar, A., Kandasamy, N., Goddard, T., Bamford, J., Subramanian, G., Lenthall, R., Littleton, E., Lamin, S., Storey, K., Ghatala, R., Banaras, A., Aeron-Thomas, J., Hazel, B., Maguire, H., Veraque, E., Harrison, L., Keshvara, R., Cunningham, J. 2018

  Abstract

  BACKGROUND: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effect of endovascular thrombectomy on functional outcome.METHODS: In this systematic review and meta-analysis, the HERMES collaboration pooled patient-level data from all randomised controlled trials that compared endovascular thrombectomy (predominantly using stent retrievers) with standard medical therapy in patients with anterior circulation ischaemic stroke, published in PubMed from Jan 1, 2010, to May 31, 2017. The primary endpoint was functional outcome, assessed by the modified Rankin Scale (mRS) at 90 days after stroke. Ischaemic core was estimated, before treatment with either endovascular thrombectomy or standard medical therapy, by CTP as relative cerebral blood flow less than 30% of normal brain blood flow or by MRI as an apparent diffusion coefficient less than 620 mum2/s. Critically hypoperfused tissue was estimated as the volume of tissue with a CTP time to maximum longer than 6 s. Mismatch volume (ie, the estimated penumbral volume) was calculated as critically hypoperfused tissue volume minus ischaemic core volume. The association of ischaemic core and penumbral volumes with 90-day mRS score was analysed with multivariable logistic regression (functional independence, defined as mRS score 0-2) and ordinal logistic regression (functional improvement by at least one mRS category) in all patients and in a subset of those with more than 50% endovascular reperfusion, adjusted for baseline prognostic variables. The meta-analysis was prospectively designed by the HERMES executive committee, but not registered.FINDINGS: We identified seven studies with 1764 patients, all of which were included in the meta-analysis. CTP was available and assessable for 591 (34%) patients and diffusion MRI for 309 (18%) patients. Functional independence was worse in patients who had CTP versus those who had diffusion MRI, after adjustment for ischaemic core volume (odds ratio [OR] 0·47 [95% CI 0·30-0·72], p=0·0007), so the imaging modalities were not pooled. Increasing ischaemic core volume was associated with reduced likelihood of functional independence (CTP OR 0·77 [0·69-0·86] per 10 mL, pinteraction=0·29; diffusion MRI OR 0·87 [0·81-0·94] per 10 mL, pinteraction=0·94). Mismatch volume, examined only in the CTP group because of the small numbers of patients who had perfusion MRI, was not associated with either functional independence or functional improvement. In patients with CTP with more than 50% endovascular reperfusion (n=186), age, ischaemic core volume, and imaging-to-reperfusion time were independently associated with functional improvement. Risk of bias between studies was generally low.INTERPRETATION: Estimated ischaemic core volume was independently associated with functional independence and functional improvement but did not modify the treatment benefit of endovascular thrombectomy over standard medical therapy for improved functional outcome. Combining ischaemic core volume with age and expected imaging-to-reperfusion time will improve assessment of prognosis and might inform endovascular thrombectomy treatment decisions.FUNDING: Medtronic.

  View details for PubMedID 30413385

• Imaging features and safety and efficacy of endovascular stroke treatment: a meta-analysis of individual patient-level data LANCET NEUROLOGY Roman, L., Menon, B. K., Blasco, J., Hernandez-Perez, M., Davalos, A., Majoie, C. M., Campbell, B. C. V., Guillemin, F., Lingsma, H., Anxionnat, R., Epstein, J., Saver, J. L., Marquering, H., Wong, J. H., Lopes, D., Reimann, G., Desal, H., Dippel, D. W. J., Coutts, S., de Rochemont, R., Yavagal, D., Ferre, J., Roos, Y. M., Liebeskind, D. S., Lenthall, R., Molina, C., Al Ajlan, F. S., Reddy, V., Dowlatshahi, D., Nader-Antoine, S., Oppenheim, C., Mitha, A. P., Davis, S. M., Weimar, C., van Oostenbrugge, R. J., Cobo, E., Kleinig, T. J., Donnan, G. A., van der Lugt, A., Demchuk, A. M., Berkhemer, O. A., Boers, A. M. M., Ford, G. A., Muir, K. W., Brown, B., Jovin, T., van Zwam, W. H., Mitchell, P. J., Hill, M. D., White, P., Bracard, S., Goyal, M., HERMES Collaborators 2018; 17 (10): 895-904

  Abstract

  Evidence regarding whether imaging can be used effectively to select patients for endovascular thrombectomy (EVT) is scarce. We aimed to investigate the association between baseline imaging features and safety and efficacy of EVT in acute ischaemic stroke caused by anterior large-vessel occlusion.In this meta-analysis of individual patient-level data, the HERMES collaboration identified in PubMed seven randomised trials in endovascular stroke that compared EVT with standard medical therapy, published between Jan 1, 2010, and Oct 31, 2017. Only trials that required vessel imaging to identify patients with proximal anterior circulation ischaemic stroke and that used predominantly stent retrievers or second-generation neurothrombectomy devices in the EVT group were included. Risk of bias was assessed with the Cochrane handbook methodology. Central investigators, masked to clinical information other than stroke side, categorised baseline imaging features of ischaemic change with the Alberta Stroke Program Early CT Score (ASPECTS) or according to involvement of more than 33% of middle cerebral artery territory, and by thrombus volume, hyperdensity, and collateral status. The primary endpoint was neurological functional disability scored on the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included symptomatic intracranial haemorrhage, parenchymal haematoma type 2 within 5 days of randomisation, and mortality within 90 days. For the primary analysis, we used mixed-methods ordinal logistic regression adjusted for age, sex, National Institutes of Health Stroke Scale score at admission, intravenous alteplase, and time from onset to randomisation, and we used interaction terms to test whether imaging categorisation at baseline modifies the association between treatment and outcome. This meta-analysis was prospectively designed by the HERMES executive committee but has not been registered.Among 1764 pooled patients, 871 were allocated to the EVT group and 893 to the control group. Risk of bias was low except in the THRACE study, which used unblinded assessment of outcomes 90 days after randomisation and MRI predominantly as the primary baseline imaging tool. The overall treatment effect favoured EVT (adjusted common odds ratio [cOR] for a shift towards better outcome on the mRS 2·00, 95% CI 1·69-2·38; p<0·0001). EVT achieved better outcomes at 90 days than standard medical therapy alone across a broad range of baseline imaging categories. Mortality at 90 days (14·7% vs 17·3%, p=0·15), symptomatic intracranial haemorrhage (3·8% vs 3·5%, p=0·90), and parenchymal haematoma type 2 (5·6% vs 4·8%, p=0·52) did not differ between the EVT and control groups. No treatment effect modification by baseline imaging features was noted for mortality at 90 days and parenchymal haematoma type 2. Among patients with ASPECTS 0-4, symptomatic intracranial haemorrhage was seen in ten (19%) of 52 patients in the EVT group versus three (5%) of 66 patients in the control group (adjusted cOR 3·94, 95% CI 0·94-16·49; pinteraction=0·025), and among patients with more than 33% involvement of middle cerebral artery territory, symptomatic intracranial haemorrhage was observed in 15 (14%) of 108 patients in the EVT group versus four (4%) of 113 patients in the control group (4·17, 1·30-13·44, pinteraction=0·012).EVT achieves better outcomes at 90 days than standard medical therapy across a broad range of baseline imaging categories, including infarcts affecting more than 33% of middle cerebral artery territory or ASPECTS less than 6, although in these patients the risk of symptomatic intracranial haemorrhage was higher in the EVT group than the control group. This analysis provides preliminary evidence for potential use of EVT in patients with large infarcts at baseline.Medtronic.

  View details for DOI 10.1016/S1474-4422(18)30242-4

  View details for Web of Science ID 000444862200017

  View details for PubMedID 30264728

• Is there added value in obtaining cervical spine MRI in the assessment of nontraumatic angiographically negative subarachnoid hemorrhage? A retrospective study and meta-analysis of the literature JOURNAL OF NEUROSURGERY Sadigh, G., Holder, C. A., Switchenko, J. M., Dehkharghani, S., Allen, J. W. 2018; 129 (3): 670-676

  Abstract

  OBJECTIVE Diagnostic algorithms for nontraumatic angiographically negative subarachnoid hemorrhage (AN-SAH) vary, and the optimal method remains subject to debate. This study assessed the added value of cervical spine MRI in identifying a cause for nontraumatic AN-SAH. METHODS Consecutive patients 18 years of age or older who presented with nontraumatic SAH between February 1, 2009, and October 31, 2014, with negative cerebrovascular catheter angiography and subsequent cervical MRI were studied. Patients with intraparenchymal, subdural, or epidural hemorrhage; recent trauma; or known vascular malformations were excluded. All cervical MR images were reviewed by two blinded neuroradiologists. The diagnostic yield of cervical MRI was calculated. A literature review was conducted to identify studies reporting the diagnostic yield of cervical MRI in patients with AN-SAH. The weighted pooled estimate of diagnostic yield of cervical MRI was calculated. RESULTS For all 240 patients (mean age 53 years, 48% male), catheter angiography was performed within 4 days after admission (median 12 hours, interquartile range [IQR] 10 hours). Cervical MRI was performed within 19 days of admission (median 24 hours, IQR 10 hours). In a single patient, cervical MRI identified a source for SAH (cervical vascular malformation). Meta-analysis of 7 studies comprising 538 patients with AN-SAH produced a pooled estimate of 1.3% (95% confidence interval 0.5%-2.5%) for diagnostic yield of cervical MRI. No statistically significant between-study heterogeneity or publication bias was identified. CONCLUSIONS Cervical MRI following AN-SAH, in the absence of findings to suggest spinal etiology, has a very low diagnostic yield and is not routinely necessary.

  View details for DOI 10.3171/2017.4.JNS163114

  View details for Web of Science ID 000443287000012

  View details for PubMedID 29027857

  View details for PubMedCentralID PMC5899067

• Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data LANCET NEUROLOGY Campbell, B. C. V., van Zwam, W. H., Goyal, M., Menon, B. K., Dippel, D. W. J., Demchuk, A. M., Bracard, S., White, P., Davalos, A., Majoie, C. M., van der Lugt, A., Ford, G. A., Perez de la Ossa, N., Kelly, M., Bourcier, R., Donnan, G. A., Roos, Y. M., Bang, O., Nogueira, R. G., Devlin, T. G., van den Berg, L. A., Clarencon, F., Burns, P., Carpenter, J., Berkhemer, O. A., Yavagal, D. R., Pereira, V., Ducrocq, X., Dixit, A., Quesada, H., Epstein, J., Davis, S. M., Jansen, O., Rubiera, M., Urra, X., Micard, E., Lingsma, H. F., Naggara, O., Brown, S., Guillemin, F., Muir, K. W., van Oostenbrugge, R. J., Saver, J. L., Jovin, T. G., Hill, M. D., Mitchell, P. J., HERMES Collaborators 2018; 17 (1): 47-53

  Abstract

  General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care.For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered.Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09-2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75-3·10, p<0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14-2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low.Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons.Medtronic.

  View details for DOI 10.1016/S1474-4422(17)30407-6

  View details for Web of Science ID 000418570500022

  View details for PubMedID 29263006

• Automated CT Perfusion Prediction of Large Vessel Acute Stroke from Intracranial Atherosclerotic Disease INTERVENTIONAL NEUROLOGY Haussen, D. C., Bouslama, M., Dehkharghani, S., Grossberg, J. A., Bianchi, N., Bowen, M., Frankel, M. R., Nogueira, R. G. 2018; 7 (6): 334-340

  Abstract

  We have observed that large vessel occlusion acute strokes (LVOS) due to intracranial atherosclerotic disease (ICAD) present with more benign CT perfusion (CTP) profiles, which we presume to potentially represent enhanced collateralization compared to embolic LVOS. We aim to determine if CTP profiles can predict ICAD in LVOS.Retrospective review of a prospectively collected interventional stroke database from September 2010 to March 2015. Patients with intracranial ICA/MCA-M1/M2 occlusions and CTP were dichotomized into ICAD versus non-ICAD etiologies. Ischemic core (relative cerebral blood flow < 30%) and hypoperfusion volumes were estimated by automated CTP.A total of 250 patients met the inclusion criteria, comprised of 21 (8%) ICAD and 229 non-ICAD etiologies. Baseline characteristics were similar between groups, except for higher HbA1c levels (p < 0.01), LDL cholesterol (p < 0.01), systolic blood pressure (p < 0.01), and lower rate of atrial fibrillation (p < 0.01) in ICAD patients. There were no significant differences in volumes of baseline ischemic core (p = 0.54) among groups. ICAD patients had smaller Tmax > 4 s, Tmax > 6 s, and Tmax > 10 s absolute lesions, and a higher ratio of Tmax > 4 s/Tmax > 6 s volumes (median 2 [1.6-2.3] vs. 1.6 [1.4-2.0]; p = 0.02). A Tmax > 4 s/Tmax > 6 s ratio ≥2 showed specificity = 73%/sensitivity = 52% for ICAD and was observed in 47.6% of ICAD versus 26.1% of non-ICAD patients (p = 0.07). Clinical outcomes were comparable amongst groups. Multivariate logistic regression revealed that Tmax > 4 s/Tmax > 6 s ratio ≥2 (OR 3.75, 95% CI 1.05-13.14, p = 0.04), higher LDL cholesterol (OR 1.1, 95% CI 1.01-1.03, p = 0.01), and higher systolic pressure (OR 1.03, 95% CI 1.01-1.04, p = 0.01) were independently associated with ICAD.An automated CTP Tmax > 4 s/Tmax > 6 s ratio ≥2 profile was found independently associated with underlying ICAD LVOS.

  View details for DOI 10.1159/000487335

  View details for Web of Science ID 000447256900006

  View details for PubMedID 30410510

  View details for PubMedCentralID PMC6216702

• The Brain Thermal Response as a Potential Neuroimaging Biomarker of Cerebrovascular Impairment AMERICAN JOURNAL OF NEURORADIOLOGY Fleischer, C. C., Wu, J., Qiu, D., Park, S., Nahab, F., Dehkharghani, S. 2017; 38 (11): 2044-2051

  Abstract

  Brain temperature is critical for homeostasis, relating intimately to cerebral perfusion and metabolism. Cerebral thermometry is historically challenged by the cost and invasiveness of clinical and laboratory methodologies. We propose the use of noninvasive MR thermometry in patients with cerebrovascular disease, hypothesizing the presence of a measurable brain thermal response reflecting the tissue hemodynamic state.Contemporaneous imaging and MR thermometry were performed in 10 patients (32-68 years of age) undergoing acetazolamide challenge for chronic, anterior circulation steno-occlusive disease. Cerebrovascular reactivity was calculated with blood oxygen level-dependent imaging and arterial spin-labeling methods. Brain temperature was calculated pre- and post-acetazolamide using previously established chemical shift thermometry. Mixed-effects models of the voxelwise relationships between the brain thermal response and cerebrovascular reactivity were computed, and the significance of model coefficients was determined with an F test (P < .05).We observed significant, voxelwise quadratic relationships between cerebrovascular reactivity from blood oxygen level-dependent imaging and the brain thermal response (x coefficient = 0.052, P < .001; x2coefficient = 0.0068, P < .001) and baseline brain temperatures (x coefficient = 0.59, P = .008; x2 coefficient = -0.13, P < .001). A significant linear relationship was observed for the brain thermal response with cerebrovascular reactivity from arterial spin-labeling (P = .001).The findings support the presence of a brain thermal response exhibiting complex but significant interactions with tissue hemodynamics, which we posit to reflect a relative balance of heat-producing versus heat-dissipating tissue states. The brain thermal response is a potential noninvasive biomarker for cerebrovascular impairment.

  View details for DOI 10.3174/ajnr.A5380

  View details for Web of Science ID 000415996600013

  View details for PubMedID 28935624

  View details for PubMedCentralID PMC5690840

• Utility of Repeat Cerebrovascular Imaging among Hospitalized Stroke Patients JOURNAL OF STROKE & CEREBROVASCULAR DISEASES Raza, S., Javalkar, V., Dehkharghani, S., Kudrimoti, A., Saindane, A., Mullins, M., Nahab, F. 2017; 26 (7): 1588-1593

  Abstract

  The purpose of this study is to evaluate the frequency and clinical utility of repeat cerebrovascular imaging with computed tomography angiography (CTA) of the head after contrast-enhanced magnetic resonance angiography (CE-MRA) of the head in acute stroke patients.All stroke patients admitted to 2 academic medical centers from January 1, 2012 through December 31, 2014 were identified as part of prospective radiology database if they underwent CE-MRA of the head followed by subsequent CTA of the head within 7 days. Two vascular neurologists blinded to CTA results retrospectively reviewed medical records including documented indications for imaging studies and clinical changes in patients to determine necessity of CTA.Of 1355 acute stroke patients who underwent CE-MRA of the head, 195 (14%) patients underwent subsequent CTA of the head within 7 days, including 33 patients with nondiagnostic CE-MRA because of motion artifact. Of the remaining 162 (12%) patients, 69 (43%) were considered to have an unnecessary CTA of the head. Multivariable logistic regression analysis identified (1) absence of new neurologic examination changes [OR 7.29; 95% CI 1.92-27.63] and (2) same documented indication for both studies [OR 6.47; 95% CI 3.04-13.78] as significant predictors of an unnecessary CTA. Changes in clinical management after CTA were significantly more common in necessary CTAs compared with studies determined to be unnecessary (42% versus 7%, P < .0001).The utility of repeat cerebrovascular imaging with CTA of the head following a diagnostic CE-MRA is low when there is no change in neurologic examination or when ordered for the same indication.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2017.02.029

  View details for Web of Science ID 000407018400034

  View details for PubMedID 28268151

• Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes EUROPEAN JOURNAL OF NEUROLOGY Rebello, L. C., Bouslama, M., Haussen, D. C., Grossberg, J. A., Dehkharghani, S., Anderson, A., Belagaje, S. R., Bianchi, N. A., Grigoryan, M., Frankel, M. R., Nogueira, R. G. 2017; 24 (6): 762-767

  Abstract

  Chronic hypoperfusion from athero-stenotic lesions is thought to lead to better collateral recruitment compared to cardioembolic strokes. It was sought to compare collateral flow in stroke patients with atrial fibrillation (AF) versus stroke patients with cervical atherosclerotic steno-occlusive disease (CASOD).This was a retrospective review of a prospectively collected endovascular database. Patients with (i) anterior circulation large vessel occlusion stroke, (ii) pre-treatment computed tomography angiography (CTA) and (iii) intracranial embolism from AF or CASOD were included. CTA collateral patterns were evaluated and categorized into two groups: absent/poor collaterals (CTA collateral score 0-1) versus moderate/good collaterals (CTA collateral score 2-4). CT perfusion was also utilized for baseline core volume and evaluation of infarct growth.A total of 122 patients fitted the inclusion criteria, of whom 88 (72%) had AF and 34 (27%) CASOD. Patients with AF were older (P < 0.01) and less often males or smokers (P = 0.04 and P < 0.01 respectively). Baseline National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT Score were comparable between groups. Collateral scores were lower in the AF group (P = 0.01) with patients having poor collaterals in 28% of cases versus 9% in the CASOD group (P = 0.03). Mortality rates (20% vs. 0%; P = 0.02) were higher in the AF patients whilst rates of any parenchymal hemorrhage (6% vs. 26%; P < 0.01) were higher in the CASOD group. On multivariable analysis, CASOD was an independent predictor of moderate/good collaterals (odds ratio 4.70; 95% confidence interval 1.17-18.79; P = 0.03).Atheroembolic strokes seem to be associated with better collateral flow compared to cardioembolic strokes. This may in part explain the worse outcomes of AF-related stroke.

  View details for DOI 10.1111/ene.13287

  View details for Web of Science ID 000405348000005

  View details for PubMedID 28432712

• Imaging Approaches to Stroke and Neurovascular Disease (vol 80, pg 681 2017) NEUROSURGERY Dehkharghani, S., Andre, J. 2017; 80 (6): 991

  View details for DOI 10.1093/neuros/nyx268

  View details for Web of Science ID 000404921300041

  View details for PubMedID 28525926

• CT Perfusion to Predict Response to Recanalization in Ischemic Stroke. Annals of neurology Lansberg, M. G., Christensen, S., Kemp, S., Mlynash, M., Mishra, N., Federau, C., Tsai, J. P., Kim, S., Nogueria, R. G., Jovin, T., Devlin, T. G., Akhtar, N., Yavagal, D. R., Haussen, D., Dehkharghani, S., Bammer, R., Straka, M., Zaharchuk, G., Marks, M. P., Albers, G. W. 2017

  Abstract

  To assess the utility of computed tomographic (CT) perfusion for selection of patients for endovascular therapy up to 18 hours after symptom onset.We conducted a multicenter cohort study of consecutive acute stroke patients scheduled to undergo endovascular therapy within 90 minutes after a baseline CT perfusion. Patients were classified as "target mismatch" if they had a small ischemic core and a large penumbra on their baseline CT perfusion. Reperfusion was defined as >50% reduction in critical hypoperfusion between the baseline CT perfusion and the 36-hour follow-up magnetic resonance imaging.Of the 201 patients enrolled, 190 patients with an adequate baseline CT perfusion study who underwent angiography were included (mean age = 66 years, median NIH Stroke Scale [NIHSS] = 16, median time from symptom onset to endovascular therapy = 5.2 hours). Rate of reperfusion was 89%. In patients with target mismatch (n = 131), reperfusion was associated with higher odds of favorable clinical response, defined as an improvement of ≥8 points on the NIHSS (83% vs 44%; p = 0.002, adjusted odds ratio [OR] = 6.6, 95% confidence interval [CI] = 2.1-20.9). This association did not differ between patients treated within 6 hours (OR = 6.4, 95% CI = 1.5-27.8) and those treated > 6 hours after symptom onset (OR = 13.7, 95% CI = 1.4-140).The robust association between endovascular reperfusion and good outcome among patients with the CT perfusion target mismatch profile treated up to 18 hours after symptom onset supports a randomized trial of endovascular therapy in this patient population. Ann Neurol 2017;81:849-856.

  View details for DOI 10.1002/ana.24953

  View details for PubMedID 28486789

• Imaging Approaches to Stroke and Neurovascular Disease NEUROSURGERY Dehkharghani, S., Andre, J. 2017; 80 (5): 681-700

  Abstract

  Imaging is paramount to the diagnosis and management of ischemic stroke, offering a battery of structural and functional probes of cerebrovascular physiology. The technical underpinnings of stroke imaging continue to evolve, bringing the neuroscience community increasingly closer to high-resolution, tissue-level biomarkers of brain perfusion, metabolism, and viability. The rapid expansion of neuroimaging in this domain has met with controversies, and in many respects, a lack of generalizable conclusions regarding optimized use in cerebrovascular disease. This review aims to provide the reader with the depth and scope of both established and emerging techniques, and an overview of prevailing viewpoints regarding neuroimaging in acute ischemic stroke.

  View details for DOI 10.1093/neuros/nyw108

  View details for Web of Science ID 000404518800023

  View details for PubMedID 28327964

• Computed Tomographic Perfusion Selection and Clinical Outcomes After Endovascular Therapy in Large Vessel Occlusion Stroke STROKE Bouslama, M., Haussen, D. C., Grossberg, J. A., Dehkharghani, S., Bowen, M. T., Rebello, L. C., Bianchi, N. A., Frankel, M. R., Nogueira, R. G. 2017; 48 (5): 1271-1277

  Abstract

  Different imaging paradigms have been used to select patients for endovascular therapy in stroke. We sought to determine whether computed tomographic perfusion (CTP) selection improves endovascular therapy outcomes compared with noncontrast computed tomography alone.Review of a prospectively collected registry of anterior circulation stroke patients undergoing stent-retriever thrombectomy at a tertiary care center between September 2010 and March 2016. Patients undergoing CTP were compared with those with noncontrast computed tomography alone. The primary outcome was the shift in the 90-day modified Rankin scale (mRS).A total of 602 patients were included. CTP-selected patients (n=365, 61%) were younger (P=0.02) and had fewer comorbidities. CTP selection (n=365, 61%) was associated with a favorable 90-day mRS shift (adjusted odds ratio [aOR]=1.49; 95% confidence interval [CI], 1.06-2.09; P=0.02), higher rates of good outcomes (90-day mRS score 0-2: 52.9% versus 40.4%; P=0.005), modified Thrombolysis in Cerebral Infarction-3 reperfusion (54.8% versus 40.1%; P<0.001), smaller final infarct volumes (24.7 mL [9.8-63.1 mL] versus 34.6 mL [13.1-88 mL]; P=0.017), and lower mortality (16.6% versus 26.8%; P=0.005). When matched on age, National Institutes of Health Stroke Scale (NIHSS) score, and glucose (n=424), CTP remained associated with a favorable 90-day mRS shift (P=0.016), lower mortality (P=0.02), and higher rates of reperfusion (P<0.001). CTP better predicted functional outcomes in patients presenting after 6 hours (as assessed by comparison of logistic regression models: Akaike information criterion: 199.35 versus 287.49 and Bayesian information criterion: 196.71 versus 283.27) and those with an Alberta Stroke Program Early Computed Tomography Score ≤7 (Akaike information criterion: 216.69 versus 334.96 and Bayesian information criterion: 213.6 versus 329.94).CTP selection is associated with a favorable mRS shift in patients undergoing stent-retriever thrombectomy. Future prospective studies are warranted.

  View details for DOI 10.1161/STROKEAHA.116.015636

  View details for Web of Science ID 000401818400033

  View details for PubMedID 28389614

• Cerebral Temperature Dysregulation: MR Thermographic Monitoring in a Nonhuman Primate Study of Acute Ischemic Stroke AMERICAN JOURNAL OF NEURORADIOLOGY Dehkharghani, S., Fleischer, C. C., Qiu, D., Yepes, M., Tong, F. 2017; 38 (4): 712-720

  Abstract

  Cerebral thermoregulation remains poorly understood. Temperature dysregulation is deeply implicated in the potentiation of cerebrovascular ischemia. We present a multiphasic, MR thermographic study in a nonhuman primate model of MCA infarction, hypothesizing detectable brain temperature disturbances and brain-systemic temperature decoupling.Three Rhesus Macaque nonhuman primates were sourced for 3-phase MR imaging: 1) baseline MR imaging, 2) 7-hour continuous MR imaging following minimally invasive, endovascular MCA stroke induction, and 3) poststroke day 1 MR imaging follow-up. MR thermometry was achieved by multivoxel spectroscopy (semi-localization by adiabatic selective refocusing) by using the proton resonance frequency chemical shift. The relationship of brain and systemic temperatures with time and infarction volumes was characterized by using a mixed-effects model.Following MCA infarction, progressive cerebral hyperthermia was observed in all 3 subjects, significantly outpacing systemic temperature fluctuations. Highly significant associations were observed for systemic, hemispheric, and global brain temperatures (F-statistic, P = .0005 for all regressions) relative to the time from stroke induction. Significant differences in the relationship between temperature and time following stroke onset were detected when comparing systemic temperatures with ipsilateral (P = .007), contralateral (P = .004), and infarction core (P = .003) temperatures following multiple-comparisons correction. Significant associations were observed between infarction volumes and both systemic (P ≤ .01) and ipsilateral (P = .04) brain temperatures, but not contralateral brain temperature (P = .08).Successful physiologic and continuous postischemic cerebral MR thermography was conducted and prescribed in a nonhuman primate infarction model to facilitate translatability. The results confirm hypothesized temperature disturbance and decoupling of physiologic brain-systemic temperature gradients. These findings inform a developing paradigm of brain thermoregulation and the applicability of brain temperature as a neuroimaging biomarker in CNS injury.

  View details for DOI 10.3174/ajnr.A5059

  View details for Web of Science ID 000398429800008

  View details for PubMedID 28126752

  View details for PubMedCentralID PMC5389900

• Enhancing Workflow Analysis in Acute Stroke Patients Using Radiofrequency Identification and Infrared-based Real-Time Location Systems JOURNAL OF THE AMERICAN COLLEGE OF RADIOLOGY Prater, A., Bowen, M., Pavich, E., Hawkins, C., Safdar, N., Fountain, J., Anderson, A., Frankel, M., Dehkharghani, S. 2017; 14 (2): 231-234

  View details for DOI 10.1016/j.jacr.2016.07.004

  View details for Web of Science ID 000394478300019

  View details for PubMedID 27577591

• Selection Paradigms for Large Vessel Occlusion Acute Ischemic Stroke Endovascular Therapy CEREBROVASCULAR DISEASES Bouslama, M., Bowen, M. T., Haussen, D. C., Dehkharghani, S., Grossberg, J. A., Rebello, L. C., Rangaraju, S., Frankel, M. R., Nogueira, R. G. 2017; 44 (5-6): 277-284

  Abstract

  Optimal patient selection methods for thrombectomy in large vessel occlusion stroke (LVOS) are yet to be established. We sought to evaluate the ability of different selection paradigms to predict favorable outcomes.Review of a prospectively collected database of endovascular patients with anterior circulation LVOS, adequate CT perfusion (CTP), National Institutes of Health Stroke Scale (NIHSS) ≥10 from September 2010 to March 2016. Patients were retrospectively assessed for thrombectomy eligibility by 4 mismatch criteria: Perfusion-Imaging Mismatch (PIM): between CTP-derived perfusion defect and ischemic core volumes; Clinical-Core Mismatch (CCM): between age-adjusted NIHSS and CTP core; Clinical-ASPECTS Mismatch (CAM-1): between age-adjusted NIHSS and ASPECTS; Clinical-ASPECTS Mismatch (CAM-2): between NIHSS and ASPECTS. Outcome measures were inclusion rates for each paradigm and their ability to predict good outcomes (90-day modified Rankin Scale 0-2).Three hundred eighty-four patients qualified. CAM-2 and CCM had higher inclusion (89.3 and 82.3%) vs. CAM-1 (67.7%) and PIM (63.3%). Proportions of selected patients were statistically different except for PIM and CAM-1 (p = 0.19), with PIM having the highest disagreement. There were no differences in good outcome rates between PIM(+)/PIM(-) (52.2 vs. 48.5%; p = 0.51) and CAM-2(+)/CAM-2(-) (52.4 vs. 38.5%; p = 0.12). CCM(+) and CAM-1(+) had higher rates compared to nonselected counterparts (53.4 vs. 38.7%, p = 0.03; 56.6 vs. 38.6%; p = 0.002). The abilities of PIM, CCM, CAM-1, and CAM-2 to predict outcomes were similar according to the c-statistic, Akaike and Bayesian information criterion.For patients with NIHSS ≥10, PIM appears to disqualify more patients without improving outcomes. CCM may improve selection, combining a high inclusion rate with optimal outcome discrimination across (+) and (-) patients. Future studies are warranted.

  View details for DOI 10.1159/000478537

  View details for Web of Science ID 000417569500005

  View details for PubMedID 28877524

• The Effects of Acetazolamide on the Evaluation of Cerebral Hemodynamics and Functional Connectivity Using Blood Oxygen Level Dependent MR Imaging in Patients with Chronic Steno-Occlusive Disease of the Anterior Circulation AMERICAN JOURNAL OF NEURORADIOLOGY Wu, J., Dehkharghani, S., Nahab, F., Allen, J., Qiu, D. 2017; 38 (1): 139-145

  Abstract

  Measuring cerebrovascular reactivity with the use of vasodilatory stimuli, such as acetazolamide, is useful for chronic cerebrovascular steno-occlusive disease. The purpose of this study was to evaluate the effects of acetazolamide on the assessment of hemodynamic impairment and functional connectivity by using noninvasive resting-state blood oxygen level-dependent MR imaging.A 20-minute resting-state blood oxygen level-dependent MR imaging scan was acquired with infusion of acetazolamide starting at 5 minutes after scan initiation. A recently developed temporal-shift analysis technique was applied on blood oxygen level-dependent MR imaging data before and after acetazolamide infusion to identify regions with hemodynamic impairment, and the results were compared by using contrast agent-based DSC perfusion imaging as the reference standard. Functional connectivity was compared with and without correction on the signal by using information from temporal-shift analysis, before and after acetazolamide infusion.Visually, temporal-shift analysis of blood oxygen level-dependent MR imaging data identified regions with compromised hemodynamics as defined by DSC, though performance deteriorated in patients with bilateral disease. The Dice similarity coefficient between temporal-shift and DSC maps was higher before (0.487 ± 0.150 by using the superior sagittal sinus signal as a reference for temporal-shift analysis) compared with after acetazolamide administration (0.384 ± 0.107) (P = .006, repeated-measures ANOVA). Functional connectivity analysis with temporal-shift correction identified brain network nodes that were otherwise missed. The accuracy of functional connectivity assessment decreased after acetazolamide administration (P = .015 for default mode network, repeated-measures ANOVA).Temporal-shift analysis of blood oxygen level-dependent MR imaging can identify brain regions with hemodynamic compromise in relation to DSC among patients with chronic cerebrovascular disease. The use of acetazolamide reduces the accuracy of temporal-shift analysis and network connectivity evaluation.

  View details for DOI 10.3174/ajnr.A4973

  View details for Web of Science ID 000392163600023

  View details for PubMedID 27758776

  View details for PubMedCentralID PMC7963661

• Body Temperature Modulates Infarction Growth following Endovascular Reperfusion AMERICAN JOURNAL OF NEURORADIOLOGY Dehkharghani, S., Bowen, M., Haussen, D. C., Gleason, T., Prater, A., Cai, Q., Kang, J., Nogueira, R. G. 2017; 38 (1): 46-51

  Abstract

  The neuronal substrate is highly sensitive to temperature elevation; however, its impact on the fate of the ischemic penumbra has not been established. We analyzed interactions between temperature and penumbral expansion among successfully reperfused patients with acute ischemic stroke, hypothesizing infarction growth and worse outcomes among patients with fever who achieve full reperfusion.Data from 129 successfully reperfused (modified TICI 2b/3) patients (mean age, 65 ± 15 years) presenting within 12 hours of onset were examined from a prospectively collected acute ischemic stroke registry. CT perfusion was analyzed to produce infarct core, hypoperfusion, and penumbral mismatch volumes. Final DWI infarction volumes were measured, and relative infarction growth was computed. Systemic temperatures were recorded throughout hospitalization. Correlational and logistic regression analyses assessed the associations between fever (>37.5°C) and both relative infarction growth and favorable clinical outcome (90-day mRS of ≤2), corrected for NIHSS score, reperfusion times, and age. An optimized model for outcome prediction was computed by using the Akaike Information Criterion.The median presentation NIHSS score was 18 (interquartile range, 14-22). Median (interquartile range) CTP-derived volumes were: core = 9.6 mL (1.5-25.3 mL); hypoperfusion = 133 mL (84.2-204 mL); and final infarct volume = 9.6 mL (8.3-45.2 mL). Highly significant correlations were observed between temperature of >37.5°C and relative infarction growth (Kendall τ correlation coefficient = 0.24, P = .002). Odds ratios for favorable clinical outcome suggested a trend toward significance for fever in predicting a 90-day mRS of ≤2 (OR = 0.31, P = .05). The optimized predictive model for favorable outcomes included age, NIHSS score, procedure time to reperfusion, and fever. Likelihood ratios confirmed the superiority of fever inclusion (P < .05). Baseline temperature, range, and maximum temperature did not meet statistical significance.These findings suggest that imaging and clinical outcomes may be affected by systemic temperature elevations, promoting infarction growth despite reperfusion.

  View details for DOI 10.3174/ajnr.A4969

  View details for Web of Science ID 000392163600009

  View details for PubMedID 27758774

  View details for PubMedCentralID PMC7963665

• Acetazolamide-augmented dynamic BOLD (aczBOLD) imaging for assessing cerebrovascular reactivity in chronic steno-occlusive disease of the anterior circulation: An initial experience NEUROIMAGE-CLINICAL Wu, J., Dehkharghani, S., Nahab, F., Qiu, D. 2017; 13: 116-122

  Abstract

  The purpose of this study was to measure cerebrovascular reactivity (CVR) in chronic steno-occlusive disease using a novel approach that couples BOLD imaging with acetazolamide (ACZ) vasoreactivity (aczBOLD), to evaluate dynamic effects of ACZ on BOLD and to establish the relationship between aczBOLD and dynamic susceptibility contrast (DSC) perfusion MRI. Eighteen patients with unilateral chronic steno-occlusive disease of the anterior circulation underwent a 20-min aczBOLD imaging protocol, with ACZ infusion starting at 5 min of scan initiation. AczBOLD reactivity was calculated on a voxel-by-voxel basis to generate CVR maps for subsequent quantitative analyses. Reduced CVR was observed in the diseased vs. the normal hemisphere both by qualitative and quantitative assessment (gray matter (GM): 4.13% ± 1.16% vs. 4.90% ± 0.98%, P = 0.002; white matter (WM): 2.83% ± 1.23% vs. 3.50% ± 0.94%, P = 0.005). In all cases BOLD signal began increasing immediately following ACZ infusion, approaching a plateau at ~ 8.5 min after infusion, with the tissue volume of reduced augmentation increasing progressively with time, peaking at 2.60 min (time range above 95% of the maximum value: 0-4.43 min) for the GM and 1.80 min (time range above 95% of the maximum value: 1.40-3.53 min) for the WM. In the diseased hemisphere, aczBOLD CVR significantly correlated with baseline DSC time-to-maximum of the residue function (Tmax) (P = 0.008 for the WM) and normalized cerebral blood flow (P = 0.003 for the GM, and P = 0.001 for the WM). AczBOLD provides a novel, safe, easily implementable approach to CVR measurement in the routine clinical environments. Further studies can establish quantitative thresholds from aczBOLD towards identification of patients at heightened risk of recurrent ischemia and cognitive decline.

  View details for DOI 10.1016/j.nicl.2016.11.018

  View details for Web of Science ID 000401413700015

  View details for PubMedID 27942454

  View details for PubMedCentralID PMC5137181

• Endovascular Treatment for Patients With Acute Stroke Who Have a Large Ischemic Core and Large Mismatch Imaging Profile JAMA NEUROLOGY Rebello, L. C., Bouslama, M., Haussen, D. C., Dehkharghani, S., Grossberg, J. A., Belagaje, S., Frankel, M. R., Nogueira, R. G. 2017; 74 (1): 34-40

  Abstract

  Endovascular therapy (ET) is typically not considered for patients with large baseline ischemic cores (irreversibly injured tissue). Computed tomographic perfusion (CTP) imaging may identify a subset of patients with large ischemic cores who remain at risk for significant infarct expansion and thus could still benefit from reperfusion to reduce their degree of disability.To compare the outcomes of patients with large baseline ischemic cores on CTP undergoing ET with the outcomes of matched controls who had medical care alone.A matched case-control study of patients with proximal occlusion after stroke (intracranial internal carotid artery and/or middle cerebral artery M1 and/or M2) on computed tomographic angiography and baseline ischemic core greater than 50 mL on CTP at a tertiary care center from May 1, 2011, through October 31, 2015. Patients receiving ET and controls receiving medical treatment alone were matched for age, baseline ischemic core volume on CTP, and glucose levels. Baseline characteristics and outcomes were compared.The primary outcome measure was the shift in the degree of disability among the treatment and control groups as measured by the modified Rankin Scale (mRS) (with scores ranging from 0 [fully independent] to 6 [dead]) at 90 days.Fifty-six patients were matched across 2 equally distributed groups (mean [SD] age, 62.25 [13.92] years for cases and 58.32 [14.79] years for controls; male, 13 cases [46%] and 14 controls [50%]). Endovascular therapy was significantly associated with a favorable shift in the overall distribution of 90-day mRS scores (odds ratio, 2.56; 95% CI, 2.50-8.47; P = .04), higher rates of independent outcomes (90-day mRS scores of 0-2, 25% vs 0%; P = .04), and smaller final infarct volumes (mean [SD], 87 [77] vs 242 [120] mL; P < .001). One control (4%) and 2 treatment patients (7%) developed a parenchymal hematoma type 2 (P > .99). The rates of hemicraniectomy (2 [7%] vs 6 [21%]; P = .10) and 90-day mortality (7 [29%] vs 11 [48%]; P = .75) were numerically lower in the intervention arm. Sensitivity analysis for patients with a baseline ischemic core greater than 70 mL (12 pairs) revealed a significant reduction in final infarct volumes (mean [SD], 110 [65] vs 319 [147] mL; P < .001) but only a nonsignificant improvement in the overall distribution of mRS scores favoring the treatment group (P = .18). All 11 patients older than 75 years had poor outcomes (mRS score >3) at 90 days.In properly selected patients, ET appears to benefit patients with large core and large mismatch profiles. Future prospective studies are warranted.

  View details for DOI 10.1001/jamaneurol.2016.3954

  View details for Web of Science ID 000393678800010

  View details for PubMedID 27820620

• Endovascular Therapy for Large Vessel Stroke in the Elderly: Hope in the New Stroke Era CEREBROVASCULAR DISEASES Lima, A., Haussen, D. C., Rebello, L. C., Dehkharghani, S., Grossberg, J., Grigoryan, M., Frankel, M., Nogueira, R. G. 2016; 42 (5-6): 421-427

  Abstract

  Acute ischemic stroke (AIS) in the elderly encompasses approximately one-third of all AIS cases. Outcome data have been for the most part discouraging in this population. We aim to evaluate the outcomes in a large contemporary series of elderly patients treated with thrombectomy.Retrospective analysis of a single-center endovascular database for consecutive elderly (≥80 years) patients treated for anterior circulation large vessel occlusion AIS between September 2010 and April 2015. Univariate- and multivariate analyses were performed to identify the predictors of good clinical outcome (90-day modified Ranking Scale [mRS] ≤2). Receiver operating characteristic curves were used to calculate the optimal final infarct volume (FIV) threshold to predict good outcomes.A total of 111 patients met our inclusion criteria (mean age 84.8 ± 4.2 years; National Institutes of Health Stroke Scale [NIHSS] score 19.1 ± 5.6; time from last-known normal to puncture, 349.6 ± 246.6 min; 33% male; 68% Alberta Stroke Program Early CT Score [ASPECTS] ≥8). The rates of successful reperfusion (modified treatment in cerebral ischemia ≥2b), symptomatic intracranial hemorrhage and 90-day mortality were 80%, 7% and 41%, respectively. The overall rate of good outcome was 29% (n = 32/111) but was 52% (n = 13/25) in patients with baseline mRS score of 0-2 who were selected based on CT perfusion and treated with stent retrievers. On multivariate analysis, only ASPECTS (OR 2.17; 95% CI 1.28-3.67.7; p = 0.004) and baseline NIHSS score (OR 0.87; 95% CI 0.77-0.97; p = 0.013) were independently associated with good outcome. A FIV ≤16 ml demonstrated the greatest accuracy for identifying good outcomes (sensitivity 75.0%, specificity 82.6%).Our results are encouraging demonstrating nearly one-third of elderly patients achieving full independence at 90 days. Contemporary treatment paradigms employing optimized patient selection and modern thrombectomy technology may result in even better outcomes.

  View details for DOI 10.1159/000446852

  View details for Web of Science ID 000390030800014

  View details for PubMedID 27454483

• Automated CT Perfusion Ischemic Core Volume and Noncontrast CT ASPECTS (Alberta Stroke Program Early CT Score) Correlation and Clinical Outcome Prediction in Large Vessel Stroke STROKE Haussen, D. C., Dehkharghani, S., Rangaraju, S., Rebello, L. C., Bouslama, M., Grossberg, J. A., Anderson, A., Belagaje, S., Frankel, M., Nogueira, R. G. 2016; 47 (9): 2318-2322

  Abstract

  The semiquantitative noncontrast CT Alberta Stroke Program Early CT Score (ASPECTS) and RAPID automated computed tomography (CT) perfusion (CTP) ischemic core volumetric measurements have been used to quantify infarct extent. We aim to determine the correlation between ASPECTS and CTP ischemic core, evaluate the variability of core volumes within ASPECTS strata, and assess the strength of their association with clinical outcomes.Review of a prospective, single-center database of consecutive thrombectomies of middle cerebral or intracranial internal carotid artery occlusions with pretreatment CTP between September 2010 and September 2015. CTP was processed with RAPID software to identify ischemic core (relative cerebral blood flow<30% of normal tissue).Three hundred and thirty-two patients fulfilled inclusion criteria. Median age was 66 years (55-75), median ASPECTS was 8 (7-9), whereas median CTP ischemic core was 11 cc (2-27). Median time from last normal to groin puncture was 5.8 hours (3.9-8.8), and 90-day modified Rankin scale score 0 to 2 was observed in 54%. The correlation between CTP ischemic core and ASPECTS was fair (R=-0.36; P<0.01). Twenty-six patients (8%) had ASPECTS <6 and CTP core ≤50 cc (37% had modified Rankin scale score 0-2, whereas 29% were deceased at 90 days). Conversely, 27 patients (8%) had CTP core >50 cc and ASPECTS ≥6 (29% had modified Rankin scale 0-2, whereas 21% were deceased at 90 days). Moderate correlations between ASPECTS and final infarct volume (R=-0.42; P<0.01) and between CTP ischemic core and final infarct volume (R=0.50; P<0.01) were observed; coefficients were not significantly influenced by the time from stroke onset to presentation. Multivariable regression indicated ASPECTS ≥6 (odds ratio 4.10; 95% confidence interval, 1.47-11.46; P=0.01) and CTP core ≤50 cc (odds ratio 3.86; 95% confidence interval, 1.22-12.15; P=0.02) independently and comparably predictive of good outcome.There is wide variability of CTP-derived core volumes within ASPECTS strata. Patient selection may be affected by the imaging selection method.

  View details for DOI 10.1161/STROKEAHA.116.014117

  View details for Web of Science ID 000383559300036

  View details for PubMedID 27507858

• Effects of Height and Blood Volume on Venous Enhancement After Gadolinium-Based Contrast Administration in MR Venography: A Paradigm Challenge and Implications for Clinical Imaging AMERICAN JOURNAL OF ROENTGENOLOGY Dehkharghani, S., Williams, T., Qiu, D., Saindane, A. M. 2016; 207 (3): 621-627

  Abstract

  The purpose of this study was to analyze quantitative and qualitative effects of estimated blood volume on venous enhancement in patients undergoing cerebral MR venography (MRV) with standard weight-based dosing of a gadolinium-based contrast agent.Fifty-two patients with normal 1.5-T cerebral MRV findings and contemporaneous height and weight measurements were included. Estimated blood volume was calculated with the Nadler formula for blood volume. Standard weight-based cerebral MRV was performed after administration of gadobenate dimeglumine (0.1 mmol/kg up to 20 mL). Venous enhancement within the superior sagittal sinus, right jugular bulb, and left jugular bulb was measured. Patients were dichotomized on the basis of administration of less than versus a maximum weight-based gadolinium-based contrast dose of 20 mL. Venographic quality was assigned by two neuroradiologists. Correlational and multiple linear regression analyses were performed.Among patients receiving less than the maximum 20 mL of gadolinium, no significant correlations were observed between weight and vascular enhancement (p > 0.05). Significant correlations between height and enhancement were observed in the superior sagittal sinus and left jugular bulb. This finding suggests that differences in estimated blood volume driven by height remain unaccounted for (p < 0.05). With the 20-mL maximal dose, a significant inverse relation was noted between estimated blood volume and contrast enhancement of all vascular segments (p < 0.05). Within all vascular segments, significant correlations were observed between enhancement and user-defined quality scores (p < 0.05). This finding suggests that optimized dosing may affect reader confidence.Standard weight-based dosing for cerebral MRV insufficiently accounts for differences in circulating blood volume. An expanded biometric dosing paradigm leveraging readily attainable subject data may mitigate unintended variations in enhancement affecting venography and other clinical imaging modalities.

  View details for DOI 10.2214/AJR.16.16049

  View details for Web of Science ID 000383980200026

  View details for PubMedID 27304717

• Utilization of Workflow Process Maps to Analyze Gaps in Critical Event Notification at a Large, Urban Hospital JOURNAL OF DIGITAL IMAGING Bowen, M., Prater, A., Safdar, N. M., Dehkharghani, S., Fountain, J. A. 2016; 29 (4): 420-424

  Abstract

  Stroke care is a time-sensitive workflow involving multiple specialties acting in unison, often relying on one-way paging systems to alert care providers. The goal of this study was to map and quantitatively evaluate such a system and address communication gaps with system improvements. A workflow process map of the stroke notification system at a large, urban hospital was created via observation and interviews with hospital staff. We recorded pager communication regarding 45 patients in the emergency department (ED), neuroradiology reading room (NRR), and a clinician residence (CR), categorizing transmissions as successful or unsuccessful (dropped or unintelligible). Data analysis and consultation with information technology staff and the vendor informed a quality intervention-replacing one paging antenna and adding another. Data from a 1-month post-intervention period was collected. Error rates before and after were compared using a chi-squared test. Seventy-five pages regarding 45 patients were recorded pre-intervention; 88 pages regarding 86 patients were recorded post-intervention. Initial transmission error rates in the ED, NRR, and CR were 40.0, 22.7, and 12.0 %. Post-intervention, error rates were 5.1, 18.8, and 1.1 %, a statistically significant improvement in the ED (p < 0.0001) and CR (p = 0.004) but not NRR (p = 0.208). This intervention resulted in measureable improvement in pager communication to the ED and CR. While results in the NRR were not significant, this intervention bolsters the utility of workflow process maps. The workflow process map effectively defined communication failure parameters, allowing for systematic testing and intervention to improve communication in essential clinical locations.

  View details for DOI 10.1007/s10278-015-9838-9

  View details for Web of Science ID 000379751200002

  View details for PubMedID 26667658

  View details for PubMedCentralID PMC4942383

• Performance of CT ASPECTS and Collateral Score in Risk Stratification: Can Target Perfusion Profiles Be Predicted without Perfusion Imaging? AJNR. American journal of neuroradiology Dehkharghani, S., Bammer, R., Straka, M., Bowen, M., Allen, J. W., Rangaraju, S., Kang, J., Gleason, T., Brasher, C., Nahab, F. 2016; 37 (8): 1399-1404

  Abstract

  Endovascular trials suggest that revascularization benefits a subset of acute ischemic stroke patients with large-artery occlusion and small-core infarct volumes. The objective of our study was to identify thresholds of noncontrast CT-ASPECTS and collateral scores on CT angiography that best predict ischemic core volume thresholds quantified by CT perfusion among patients with acute ischemic stroke.Fifty-four patients with acute ischemic stroke (<12 hours) and MCA/intracranial ICA occlusion underwent NCCT/CTP during their initial evaluation. CTP analysis was performed on a user-independent platform (RApid processing of PerfusIon and Diffusion), computing core infarct (defined as CBF of <30% normal). A target mismatch profile consisting of infarction core of ≤50 mL was selected to define candidates with acute ischemic stroke likely to benefit from revascularization.NCCT-ASPECTS of ≥9 with a CTA collateral score of 3 had 100% specificity for identifying patients with a CBF core volume of ≤50 mL. NCCT-ASPECTS of ≤6 had 100% specificity for identifying patients with a CBF core volume of >50 mL. In our cohort, 44 (81%) patients had an NCCT-ASPECTS of ≥9, a CTA collateral score of 3, or an NCCT-ASPECTS of ≤6.Using an NCCT-ASPECTS of ≥9 or a CTA collateral score of 3 best predicts CBF core volume infarct of ≤50 mL, while an NCCT-ASPECTS of ≤6 best predicts a CBF core volume infarct of >50 mL. Together these thresholds suggest that a specific population of patients with acute ischemic stroke not meeting such profiles may benefit most from CTP imaging to determine candidacy for revascularization.

  View details for DOI 10.3174/ajnr.A4727

  View details for PubMedID 26965466

• Associations Between CTP Ischemic Core Volume, ASPECTS Scores and Clinical Outcomes After Endovascular Reperfusion Marks, M. P., Christensen, S., Tsai, J. P., Mlynash, M., Kemp, S., Mishra, N., Federau, C., Kim, S., Haussen, D. C., Dehkharghani, S., Devlin, T. G., Yavagal, D. R., Akhtar, N., Jovin, T., Nogueira, R. G., Bammer, R., Straka, M., Zaharchuk, G., Albers, G. W., Lansberg, M. G. LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956103167

• Infarct growth despite full reperfusion in endovascular therapy for acute ischemic stroke. Journal of neurointerventional surgery Haussen, D. C., Nogueira, R. G., Elhammady, M. S., Yavagal, D. R., Aziz-Sultan, M. A., Johnson, J. N., Gaynor, B. G., Jen, S., Dehkharghani, S., Peterson, E. C. 2016; 8 (2): 117-21

  Abstract

  To explore the predictors of infarct core expansion despite full reperfusion after intra-arterial therapy (IAT).We retrospectively reviewed 604 consecutive patients who underwent IAT for anterior circulation large vessel occlusion acute ischemic stroke in two tertiary centers (2008-2013/2010-2013). Sixty patients selected by MRI or CT perfusion presenting within <24 h of onset with modified Thrombolysis In Cerebral Infarction (mTICI) grade 3 or 2c reperfusion were included. Significant infarct growth (SIG) was defined as infarct expansion >11.6 mL.Mean age was 67.0±13.7 years, 56% were men. Mean National Institute of Health Stroke Scale (NIHSS) score was 16.2±6.1, time from onset to puncture was 6.8±3.1 h, and procedure length was 1.3±0.6 h. MRI was used for baseline core analysis in 43% of patients. Mean baseline infarct volume was 17.1±19.1 mL, absolute infarct growth was 30.6±74.5 mL, and final infarct volume was 47.7±77.7 mL. Overall, 35% of patients had SIG. Three of 21 patients (14%) treated with stent-retrievers had SIG compared with 14 of 39 (36%) with first-generation devices. Eight of 21 patients (38%) with intravenous tissue plasminogen activator (IV t-PA) had infarct growth compared with 25/39 (64%) without. 23% of patients with SIG had a modified Rankin Scale score ≤2 at 3 months compared with 48% of those without SIG. Multivariate logistic regression indicated that race affected infarct growth. Use of IV t-PA (p=0.03) and stent-retrievers (p=0.03) were independently and inversely correlated with SIG.Despite full reperfusion, infarct growth is relatively frequent and may explain poor clinical outcomes in this setting. Ethnicity was found to influence SIG. Use of IV t-PA and stent-retrievers were associated with less infarct core expansion.

  View details for DOI 10.1136/neurintsurg-2014-011497

  View details for PubMedID 25540178

• Severe CT Perfusion Bolus Delays Predict Infarct Growth Despite Reperfusion Christensen, S., Tsai, J., Kemp, S., Mishra, N., Kim, S., Mlynash, M., Federau, C., Bammer, R., Frankel, M., Dehkharghani, S., Devlin, T., Yavagal, D., Straka, M., Zaharchuk, G., Akhtar, N., Haussen, D., Marks, M., Jovin, T., Nogueira, R., Albers, G., Lansberg, M. LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956102139

• Arterial Occlusive Lesion Location Does Not Impact Functional Outcome in Patients with Endovascular Reperfusion Kim, S., Christensen, S., Mlynash, M., Tsai, J. P., Federau, C., Kemp, S. M., Mishra, N., Frankel, M., Dehkharghani, S., Devlin, T. G., Yavagal, D. R., Akhtar, N., Tudor, J., Nogueira, R., Bammer, R., Straka, M., Zaharchuk, G., Albers, G. W., Marks, M., Lansberg, M. LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956102122

• The Malignant CTP Imaging Profile Predicts Worse Functional Outcomes Mlynash, M., Christensen, S., Kemp, S. M., Mishra, N., Federau, C., Tsai, J. P., Kim, S., Frankel, M., Dehkharghani, S., Devlin, T. G., Yavagal, D. R., Akhtar, N., Jovin, T., Nogueira, R., Bammer, R., Straka, M., Zaharchuk, G., Albers, G. W., Marks, M. P., Lansberg, M. G., CRISP Investigators LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956100155

• Main Results of the CTP to Predict Response to Recanalization in Ischemic Stroke Project (CRISP) Lansberg, M. G., Christensen, S., Kemp, S., Mlynash, M., Mishra, N., Federau, C., Tsai, J. P., Kim, S., Haussen, D. C., Dehkharghani, S., Devlin, T. G., Yavagal, D. R., Akhtar, N., Jovin, T., Nogueira, R. G., Bammer, R., Straka, M., Zaharchuk, G., Marks, M. P., Albers, G. W. LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956100055

• Patient Selection is a Better Predictor of Good Outcome Than Time to Reperfusion in Acute Ischemic Stroke. Tsai, J. P., Mlynash, M., Christensen, S., Kemp, S., Mishra, N., Federau, C., Kim, S., Frankel, M., Dehkharghani, S., Devlin, T. G., Yavagal, D. R., Akhtar, N., Jovin, T., Nogueira, R. G., Bammer, R., Straka, M., Zaharchuk, G., Gregory, W., Marks, M. P., Lansberg, M. G. LIPPINCOTT WILLIAMS & WILKINS. 2016

  View details for Web of Science ID 000399956100005

• Automated CT Perfusion for Ischemic Core Volume Prediction in Tandem Anterior Circulation Occlusions INTERVENTIONAL NEUROLOGY Haussen, D. C., Dehkharghani, S., Grigoryan, M., Bowen, M., Rebello, L. C., Nogueira, R. G. 2016; 5 (1-2): 81-88

  Abstract

  CT perfusion (CTP) predicts ischemic core volumes in acute ischemic stroke (AIS); however, assumptions made within the pharmacokinetic model may engender errors by the presence of tracer delay or dispersion. We aimed to evaluate the impact of hemodynamic disturbance due to extracranial anterior circulation occlusions upon the accuracy of ischemic core volume estimation with an automated perfusion analysis tool (RAPID) among AIS patients with large-vessel occlusions.A prospectively collected, interventional database was retrospectively reviewed for all cases of endovascular treatment of AIS between September 2010 and March 2015 for patients with anterior circulation occlusions with baseline CTP and full reperfusion (mTICI3).Out of 685 treated patients, 114 fit the inclusion criteria. Comparison between tandem (n = 21) and nontandem groups (n = 93) revealed similar baseline ischemic core (20 ± 19 vs. 19 ± 25 cm(3); p = 0.8), Tmax >6 s (175 ± 109 vs. 162 ± 118 cm(3); p = 0.6), Tmax >10 s (90 ± 84 vs. 90 ± 91 cm(3); p = 0.9), and final infarct volumes (45 ± 47 vs. 37 ± 45 cm(3); p = 0.5). Baseline core volumes were found to correlate with final infarct volumes for the tandem (r = 0.49; p = 0.02) and nontandem (r = 0.44; p < 0.01) groups. The mean absolute difference between estimated core and final infarct volume was similar between patients with and those without (24 ± 41 vs. 17 ± 41 cm(3); p = 0.5) tandem lesions.The prediction of baseline ischemic core volumes through an optimized CTP analysis employing rigorous normalization, thresholding, and voxel-wise analysis is not significantly influenced by the presence of underlying extracranial carotid steno-occlusive disease in large-vessel AIS.

  View details for DOI 10.1159/000445763

  View details for Web of Science ID 000379220700008

  View details for PubMedID 27610125

  View details for PubMedCentralID PMC4934474

• Utility of double inversion recovery MRI in paediatric epilepsy BRITISH JOURNAL OF RADIOLOGY Soares, B. P., Porter, S. G., Saindane, A. M., Dehkharghani, S., Desai, N. K. 2016; 89 (1057): 20150325

  Abstract

  Detecting focal abnormalities in MRI examinations of children with epilepsy can be a challenging task given the frequently subtle appearance of cortical dysplasia, mesial temporal sclerosis and similar lesions. In this report, we demonstrate the utility of double inversion recovery MRI in the detection of paediatric epileptogenic abnormalities, promoted primarily by increased lesion conspicuity due to complementary suppression of both cerebrospinal fluid and normal white matter signal.

  View details for DOI 10.1259/bjr.20150325

  View details for Web of Science ID 000368418500009

  View details for PubMedID 26529229

  View details for PubMedCentralID PMC4985945

• Large Volumes of Critically Hypoperfused Penumbral Tissue Do Not Preclude Good Outcomes After Complete Endovascular Reperfusion: Redefining Malignant Profile. Stroke Nogueira, R. G., Haussen, D. C., Dehkharghani, S., Rebello, L. C., Lima, A., Bowen, M., Belagaje, S., Anderson, A., Frankel, M. 2016; 47 (1): 94-8

  Abstract

  Acute ischemic stroke patients with large volumes of severe hypoperfusion (Tmax>10 s>100 mL) on magnetic resonance imaging have a higher likelihood of intracranial hemorrhage and poor outcomes after reperfusion. We aim to evaluate the impact of the extent of Tmax>10 s CTP lesions in patients undergoing successful treatment.Retrospective database review of endovascular acute ischemic stroke treatment between September 2010 and March 2015 for patients with anterior circulation occlusions with baseline RAPID CTP and full reperfusion (mTICI 3). The primary outcome was the impact of the Tmax>10 s lesion spectrum on infarct growth. Secondary safety and efficacy outcomes included parenchymal hematomas and good clinical outcomes (90-day modified Rankin Scale score, 0-2).Of 684 treated patients, 113 patients fit the inclusion criteria. Tmax>10 s>100 mL patients (n=37) had significantly higher baseline National Institutes of Health Stroke Scale (20.7±3.8 versus 17.0±5.9; P<0.01), more internal carotid artery terminus occlusions (29% versus 9%; P=0.02), and larger baseline (38.6±29.6 versus 11.7±15.8 mL; P<0.01) and final (60.7±60.0 versus 29.4±33.9 mL; P<0.01) infarct volumes when compared with patients without Tmax>10 s>100 mL (n=76); however, the 2 groups were otherwise well balanced. There were no significant differences in infarct growth (22.1±51.6 versus 17.8±32.4 mL; P=0.78), severe intracranial hemorrhage (PH2: 2% versus 4%; P=0.73), good outcomes (90-day mRS score, 0-2: 56% versus 59%; P=0.83), or 90-day mortality (16% versus 7%; P=0.28). On multivariate analysis, only baseline National Institutes of Health Stroke Scale (odds ratio, 1.19; 95% confidence interval, 1.06-1.34; P<0.01) and baseline infarct core volume (odds ratio, 1.05; 95% confidence interval, 1.02-1.08; P<0.01) were independently associated with Tmax>10 s>100 mL. There was no association between Tmax>10 s>100 mL with any PH, good outcome, or infarct growth.In the setting of limited baseline ischemic cores, large Tmax>10 s lesions on computed tomographic perfusion do not seem to be associated with a higher risk of parenchymal hematomas and do not preclude good outcomes in patients undergoing endovascular reperfusion with contemporary technology.

  View details for DOI 10.1161/STROKEAHA.115.011360

  View details for PubMedID 26604248

• Magnetic Resonance Imaging in Ischemic Stroke and Cerebral Venous Thrombosis. Topics in magnetic resonance imaging : TMRI Krieger, D. A., Dehkharghani, S. 2015; 24 (6): 331-52

  Abstract

  Imaging is indispensable in the evaluation of patients presenting with central nervous system emergencies. Although computed tomography (CT) is the mainstay of initial assessment and triage, magnetic resonance imaging (MRI) has become vital in expanding diagnostic capabilities, refining management strategies, and developing our understanding of disease processes. Ischemic stroke and cerebral venous thrombosis are 2 areas wherein MRI is actively revolutionizing patient care. Familiarity with the imaging manifestations of these 2 disease processes is crucial for any radiologist reading brain MR studies. In this review, the fundamentals of image interpretation will be addressed in-depth. Furthermore, advanced imaging techniques which are redefining the role of emergency MRI will be outlined, with a focus on the pathophysiological mechanisms that underlie image interpretation. In particular, emerging data surrounding the use of MR perfusion imaging in acute stroke management portend dramatic shifts in neurointerventional management. To this end, a review of the recent stroke literature will hopefully enhance the radiologist's role in both meaningful reporting and multidisciplinary teamwork.

  View details for DOI 10.1097/RMR.0000000000000067

  View details for PubMedID 26636639

• Performance and Predictive Value of a User-Independent Platform for CT Perfusion Analysis: Threshold-Derived Automated Systems Outperform Examiner-Driven Approaches in Outcome Prediction of Acute Ischemic Stroke AMERICAN JOURNAL OF NEURORADIOLOGY Dehkharghani, S., Bammer, R., Straka, M., Albin, L. S., Kass-Hout, O., Allen, J. W., Rangaraju, S., Qiu, D., Winningham, M. J., Nahab, F. 2015; 36 (8): 1419-1425

  Abstract

  Treatment strategies in acute ischemic stroke aim to curtail ischemic progression. Emerging paradigms propose patient subselection using imaging biomarkers derived from CT, CTA, and CT perfusion. We evaluated the performance of a fully-automated computational tool, hypothesizing enhancements compared with qualitative approaches. The correlation between imaging variables and clinical outcomes in a cohort of patients with acute ischemic stroke is reported.Sixty-two patients with acute ischemic stroke and MCA or ICA occlusion undergoing multidetector CT, CTA, and CTP were retrospectively evaluated. CTP was processed on a fully operator-independent platform (RApid processing of PerfusIon and Diffusion [RAPID]) computing automated core estimates based on relative cerebral blood flow and relative cerebral blood volume and hypoperfused tissue volumes at varying thresholds of time-to-maximum. Qualitative analysis was assigned by 2 independent reviewers for each variable, including CT-ASPECTS, CBV-ASPECTS, CBF-ASPECTS, CTA collateral score, and CTA clot burden score. Performance as predictors of favorable clinical outcome and final infarct volume was established for each variable.Both RAPID core estimates, CT-ASPECTS, CBV-ASPECTS, and clot burden score correlated with favorable clinical outcome (P < .05); CBF-ASPECTS and collateral score were not significantly associated with favorable outcome, while hypoperfusion estimates were variably associated, depending on the selected time-to-maximum thresholds. Receiver operating characteristic analysis demonstrated disparities among tested variables, with RAPID core and hypoperfusion estimates outperforming all qualitative approaches (area under the curve, relative CBV = 0.86, relative CBF = 0.81; P < .001).Qualitative approaches to acute ischemic stroke imaging are subject to limitations due to their subjective nature and lack of physiologic information. These findings support the benefits of high-speed automated analysis, outperforming conventional methodologies while limiting delays in clinical management.

  View details for DOI 10.3174/ajnr.A4363

  View details for Web of Science ID 000359657400008

  View details for PubMedID 25999410

• Stent-Retriever Thrombectomy after Intravenous t-PA vs. t-PA Alone in Stroke NEW ENGLAND JOURNAL OF MEDICINE Saver, J. L., Goyal, M., Bonafe, A., Diener, H., Levy, E. I., Pereira, V. M., Albers, G. W., Cognard, C., Cohen, D. J., Hacke, W., Jansen, O., Jovin, T. G., Mattle, H. P., Nogueira, R. G., Siddiqui, A. H., Yavagal, D. R., Baxter, B. W., Devlin, T. G., Lopes, D. K., Reddy, V. K., de Rochemont, R. d., Singer, O. C., Jahan, R. 2015; 372 (24): 2285-2295

  Abstract

  Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome.We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset (intervention group). Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions. The primary outcome was the severity of global disability at 90 days, as assessed by means of the modified Rankin scale (with scores ranging from 0 [no symptoms] to 6 [death]).The study was stopped early because of efficacy. At 39 centers, 196 patients underwent randomization (98 patients in each group). In the intervention group, the median time from qualifying imaging to groin puncture was 57 minutes, and the rate of substantial reperfusion at the end of the procedure was 88%. Thrombectomy with the stent retriever plus intravenous t-PA reduced disability at 90 days over the entire range of scores on the modified Rankin scale (P<0.001). The rate of functional independence (modified Rankin scale score, 0 to 2) was higher in the intervention group than in the control group (60% vs. 35%, P<0.001). There were no significant between-group differences in 90-day mortality (9% vs. 12%, P=0.50) or symptomatic intracranial hemorrhage (0% vs. 3%, P=0.12).In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.).

  View details for DOI 10.1056/NEJMoa1415061

  View details for Web of Science ID 000356019200004

  View details for PubMedID 25882376

• Dose Reduction in Contrast-Enhanced Cervical MR Angiography: Field Strength Dependency of Vascular Signal Intensity, Contrast Administration, and Arteriographic Quality. AJR. American journal of roentgenology Dehkharghani, S., Qiu, D., Albin, L. S., Saindane, A. M. 2015; 204 (6): W701-6

  Abstract

  Cervical contrast-enhanced MR angiography (MRA) has proven accurate and superior to noncontrast alternatives. We proposed the systematic investigation of dose reduction in contrast-enhanced MRA, hypothesizing heightened tolerance at 3 T vs 1.5 T. Quantitative and qualitative features were compared between full-dose and 50%-reduced dose examinations at 1.5 T and 3 T.One hundred eight cervical contrast-enhanced MRA examinations were reviewed for qualitative and quantitative (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) features across four dose-field strength combinations: 1.5 T, 0.05 mmol/kg; 3 T, 0.05 mmol/kg; 1.5 T, 0.1 mmol/kg; and 3 T, 0.1 mmol/kg. Quantitative features were evaluated among the following segments: aortic arch, common carotid arteries, common carotid bifurcations, and cervical internal carotid arteries. A qualitative visual rating scale was applied for the same segments as well as to the vertebral arteries along their proximal (V1), intraforaminal (V2), and distal extraforaminal (V3) courses. Significant between-group differences were reported at p < 0.05.Qualitatively good arteriography was observed in all segments for all protocols. No significant qualitative differences between protocols were noted throughout evaluation of the anterior cervical circulation. Significant qualitative differences were observed only for V2 and V3 segments at half-dose 1.5-T compared with the remaining protocols (p < 0.05). No significant quantitative differences were present between full-dose and dose-reduced 3-T MRA in any segment. At 1.5 T, significant decrement in SNR and CNR at half-dose was present only within the cervical internal carotid artery.Dose reduction in cervical contrast-enhanced MRA is feasible at 3 T without significant compromise in arteriographic quality in most segments. Particularly at 3 T, arteriography is quantitatively and qualitatively robust and may be advisable in high-risk patients.

  View details for DOI 10.2214/AJR.14.13435

  View details for PubMedID 26001259

• Proton resonance frequency chemical shift thermometry: experimental design and validation toward high-resolution noninvasive temperature monitoring and in vivo experience in a nonhuman primate model of acute ischemic stroke. AJNR. American journal of neuroradiology Dehkharghani, S., Mao, H., Howell, L., Zhang, X., Pate, K. S., Magrath, P. R., Tong, F., Wei, L., Qiu, D., Fleischer, C., Oshinski, J. N. 2015; 36 (6): 1128-35

  Abstract

  Applications for noninvasive biologic temperature monitoring are widespread in biomedicine and of particular interest in the context of brain temperature regulation, where traditionally costly and invasive monitoring schemes limit their applicability in many settings. Brain thermal regulation, therefore, remains controversial, motivating the development of noninvasive approaches such as temperature-sensitive nuclear MR phenomena. The purpose of this work was to compare the utility of competing approaches to MR thermometry by using proton resonance frequency chemical shift. We tested 3 methodologies, hypothesizing the feasibility of a fast and accurate approach to chemical shift thermometry, in a phantom study at 3T.A conventional, paired approach (difference [DIFF]-1), an accelerated single-scan approach (DIFF-2), and a new, further accelerated strategy (DIFF-3) were tested. Phantom temperatures were modulated during real-time fiber optic temperature monitoring, with MR thermometry derived simultaneously from temperature-sensitive changes in the water proton chemical shift (∼0.01 ppm/°C). MR thermometry was subsequently performed in a series of in vivo nonhuman primate experiments under physiologic and ischemic conditions, testing its reproducibility and overall performance.Chemical shift thermometry demonstrated excellent agreement with phantom temperatures for all 3 approaches (DIFF-1: linear regression R(2) = 0.994; P < .001; acquisition time = 4 minutes 40 seconds; DIFF-2: R(2) = 0.996; P < .001; acquisition time = 4 minutes; DIFF-3: R(2) = 0.998; P < .001; acquisition time = 40 seconds).These findings confirm the comparability in performance of 3 competing approaches to MR thermometry and present in vivo applications under physiologic and ischemic conditions in a primate stroke model.

  View details for DOI 10.3174/ajnr.A4241

  View details for PubMedID 25655874

  View details for PubMedCentralID PMC4894329

• Perfusion imaging in the 3-hour time window predicts a tPA-associated hemorrhage in acute ischemic stroke. The neurologist Rangaraju, S., Edwards, A., Dehkharghani, S., Nahab, F. 2015; 19 (3): 68-9

  Abstract

  Perfusion imaging is being evaluated in acute ischemic stroke patients to identify those who may benefit from reperfusion therapies beyond the standard thrombolytic time window but limited data are available on its utility in patients presenting within the standard thrombolytic time window. We report a case of a patient presenting within the 3-hour time window where computerized tomographic perfusion imaging before intravenous thrombolysis identified a large volume of severely ischemic tissue and where intravenous tissue plasminogen activator administration subsequently resulted in a fatal intracerebral hemorrhage. Whether perfusion imaging can predict an increased risk of tissue plasminogen activator-associated symptomatic hemorrhage in patients presenting within the standard thrombolytic time window requires further study.

  View details for DOI 10.1097/NRL.0000000000000011

  View details for PubMedID 25692511

  View details for PubMedCentralID PMC4333720

• Contrast-enhanced time-resolved MRA for pre-angiographic evaluation of suspected spinal dural arterial venous fistulas. Journal of neurointerventional surgery Saindane, A. M., Boddu, S. R., Tong, F. C., Dehkharghani, S., Dion, J. E. 2015; 7 (2): 135-40

  Abstract

  Spinal digital subtraction angiography (DSA) is the gold standard for diagnosis of spinal dural arterial venous fistulas (SDAVFs), but can require extensive time, radiation exposure and contrast dose. We hypothesize that contrast-enhanced time-resolved MR angiography (CE-TR MRA) will have utility for the non-invasive diagnosis and pre-angiographic localization of SDAVFs.Eighteen patients underwent both CE-TR MRA and DSA for suspected SDAVFs, with DSA performed a median of 11 days (range 0-41) after MRA. CE-TR MRA was performed on a 1.5 T GE unit using Time Resolved Imaging of Contrast Kinetics (TRICKS). CE-TR MRA and DSA images were evaluated for the presence of SDAVFs and location of the feeding arterial supply, with DSA as the reference standard. DSA was also evaluated for the number of vessels catheterized, contrast volume and fluoroscopic and procedure times.Eight of the 18 patients were positive for SDAVF on DSA. Sensitivity, specificity, positive predictive value and negative predictive value for the 18 CE-TR MRAs were 88%, 90%, 88% and 90%, respectively. Localization of the SDAVF arterial supply on CE-TR MRA was within one vertebral level from DSA for 6/7 SDAVFs. Compared with patients with a SDAVF and feeding artery identified on CE-TR MRA, patients with negative or suboptimal CE-TR MRA had a significantly increased number of vessels catheterized (p=0.027) and larger contrast volumes (p=0.022).CE-TR MRA is a useful initial examination for the diagnosis and localization of SDAVFs, with a high concordance rate with DSA. When CE-TR MRA demonstrates a SDAVF, the number of catheterized vessels and contrast dose can be decreased during DSA.

  View details for DOI 10.1136/neurintsurg-2013-010981

  View details for PubMedID 24463440

• Contrast-enhanced time-resolved MRA for follow-up of intracranial aneurysms treated with the pipeline embolization device. AJNR. American journal of neuroradiology Boddu, S. R., Tong, F. C., Dehkharghani, S., Dion, J. E., Saindane, A. M. 2014; 35 (11): 2112-8

  Abstract

  Endovascular reconstruction and flow diversion by using the Pipeline Embolization Device is an effective treatment for complex cerebral aneurysms. Accurate noninvasive alternatives to DSA for follow-up after Pipeline Embolization Device treatment are desirable. This study evaluated the accuracy of contrast-enhanced time-resolved MRA for this purpose, hypothesizing that contrast-enhanced time-resolved MRA will be comparable with DSA and superior to 3D-TOF MRA.During a 24-month period, 37 Pipeline Embolization Device-treated intracranial aneurysms in 26 patients underwent initial follow-up by using 3D-TOF MRA, contrast-enhanced time-resolved MRA, and DSA. MRA was performed on a 1.5T unit by using 3D-TOF and time-resolved imaging of contrast kinetics. All patients underwent DSA a median of 0 days (range, 0-68) after MRA. Studies were evaluated for aneurysm occlusion, quality of visualization of the reconstructed artery, and measurable luminal diameter of the Pipeline Embolization Device, with DSA used as the reference standard.The sensitivity, specificity, and positive and negative predictive values of contrast-enhanced time-resolved MRA relative to DSA for posttreatment aneurysm occlusion were 96%, 85%, 92%, and 92%. Contrast-enhanced time-resolved MRA demonstrated superior quality of visualization (P = .0001) and a higher measurable luminal diameter (P = .0001) of the reconstructed artery compared with 3D-TOF MRA but no significant difference compared with DSA. Contrast-enhanced time-resolved MRA underestimated the luminal diameter of the reconstructed artery by 0.965 ± 0.497 mm (27% ± 13%) relative to DSA.Contrast-enhanced time-resolved MRA is a reliable noninvasive method for monitoring intracranial aneurysms following flow diversion and vessel reconstruction by using the Pipeline Embolization Device.

  View details for DOI 10.3174/ajnr.A4008

  View details for PubMedID 24994828

  View details for PubMedCentralID PMC7965189

• CT-guided nerve block for pudendal neuralgia: diagnostic and therapeutic implications. AJR. American journal of roentgenology Mamlouk, M. D., vanSonnenberg, E., Dehkharghani, S. 2014; 203 (1): 196-200

  Abstract

  The objective of our study was to help clarify the role of CT-guided pudendal nerve blocks in the problematic and poorly understood entity of pudendal neuralgia (PN).Over a 1-year period, 52 CT-guided pudendal nerve blocks were performed in 31 patients (28 women, three men; age range, 22-80 years) who suffered from chronic pelvic pain with a presumed diagnosis of PN. A combination of anesthetic and steroid was injected into the pudendal (Alcock) canal. Pre- and postprocedural pain scores (0-10) were tallied and assessed by Student t tests. A p value < 0.05 was indicative of a significant difference.All procedures were successful technically, which was defined as contrast material filling the pudendal canal on CT and subsequent infusion of anesthetic and steroid. Pre- and postprocedural pain scores ranged from 2 to 10 (mean score, 6.13) and 0-10 (mean score, 2.14), respectively; the difference was statistically significant for each nerve block session (first session, p < 0.001; second session, p < 0.001; third session, p = 0.049). Of the 31 patients, two had long-term relief with pudendal nerve blocks alone. Fourteen had subsequent surgery based on initial improvement with block(s), and all 14 patients improved with surgical nerve release. Two patients had no diagnostic response and the diagnosis of PN was excluded. The gynecologic service followed the remaining 13 patients clinically.CT-guided pudendal nerve blocks appear to be valuable diagnostically for PN and uncommonly therapeutically. On the basis of these preliminary results, we have developed an algorithm for the role of the procedure for PN.

  View details for DOI 10.2214/AJR.13.11346

  View details for PubMedID 24951215

• Redefining normal facial nerve enhancement: healthy subject comparison of typical enhancement patterns--unenhanced and contrast-enhanced spin-echo versus 3D inversion recovery-prepared fast spoiled gradient-echo imaging. AJR. American journal of roentgenology Dehkharghani, S., Lubarsky, M., Aiken, A. H., Kang, J., Hudgins, P. A., Saindane, A. M. 2014; 202 (5): 1108-13

  Abstract

  Normal facial nerve enhancement patterns derived from spin-echo (SE) sequences have not been systematically compared on contrast-enhanced 3D inversion recovery-prepared fast spoiled gradient-echo (IR-FSPGR) sequences, now in widespread use. We hypothesize that features unique to IR-FSPGR may engender differences in the appearance of the normal facial nerve, which may confound analysis of pathologic enhancement. We compared unenhanced and contrast-enhanced SE and IR-FSPGR sequences in a cohort of patients without facial nerve pathology.Twenty-three patients without facial nerve pathology were examined. Unenhanced and contrast-enhanced signal intensity (SI) of seven facial nerve segments was assessed on SE and IR-FSPGR by two neuroradiologists. SI was assigned a value of 0-3 (0, absent; 1, faint; 2, equivalent to brain; 3, equivalent to enhancing dural sinus). Statistically significant differences were assessed for each segment.Significantly higher unenhanced and contrast-enhanced SI was present in most facial nerve segments on IR-FSPGR compared with SE, including cisternal, canalicular, labyrinthine, and geniculate segments (p ≤ 0.01). Enhancement patterns were generally similar; however, significant enhancement of the labyrinthine segment was detected only on SE (p = 0.011). For unenhanced images, mean kappa statistic was 0.32, and for the contrast-enhanced images, mean kappa statistic was 0.04, implying fair and slight agreement between readers, respectively.Significantly greater SI is observed in most facial nerve segments on both unenhanced and contrast-enhanced IR-FSPGR among healthy subjects and may be misinterpreted as pathologic when evaluated in the context of existing enhancement paradigms. Examiners should remain cognizant of normal deviations from expected enhancement patterns in IR-FSPGR imaging to avoid misdiagnosis and other interpretive pitfalls.

  View details for DOI 10.2214/AJR.13.11659

  View details for PubMedID 24758667

• Primary CNS natural killer/T-cell lymphoma of the nasal type presenting in a woman: case report and review of the literature. Journal of clinical oncology : official journal of the American Society of Clinical Oncology Prajapati, H. J., Vincentelli, C., Hwang, S. N., Voloschin, A., Crocker, I., Dehkharghani, S. 2014; 32 (8): e26-9

  View details for DOI 10.1200/JCO.2012.47.6796

  View details for PubMedID 24419127

• Improved quality and diagnostic confidence achieved by use of dose-reduced gadolinium blood-pool agents for time-resolved intracranial MR angiography. AJNR. American journal of neuroradiology Dehkharghani, S., Kang, J., Saindane, A. M. 2014; 35 (3): 450-6

  Abstract

  Time-resolved MRA with the use of bolus injection of paramagnetic agents has proved valuable in neurovascular imaging. Standard contrast agents have limited blood-pool residence times, motivating the development of highly protein-bound blood-pool agents with greater relaxivity and longer intravascular residence, affording improved image quality at lesser doses. This study represents the first comparison of blood-pool agents to standard agents in time-resolved cerebral MRA.One hundred datasets were acquired at 1.5 T by use of a standardized, time-resolved MRA protocol. Patients received either unit dosing of a standard extracellular agent at 0.1 mmol/kg or a blood-pool agent at 0.03 mmol/kg. Peak arterial and venous enhancement phases were identified and subsequently scored qualitatively by use of a 4-point Likert scale, with attention to 6 vascular segments: 1) intracranial ICA; 2) MCA M1; 3) MCA M2; 4) MCA M3; 5) deep cerebral veins; and 6) dural venous sinuses.Fifty MR angiographies were acquired with each agent. No significant differences were found between agents in generation of uncontaminated arteriograms. Blood-pool agents, at 67% dose reduction, were of significantly greater quality across most vascular segments, including ICA (P = .019), M2 (P = .003), and M3 (P < .01). Superiority in the M1 segment approached significance (P = .059). Significantly better venographic quality was noted for deep venous structures (P = .016) with the use of blood-pool agents.Blood-pool agents provide superior demonstration of most intracranial vessels in time-resolved MRA compared with standard agents, at reduced doses. The greater relaxation enhancement and more favorable dosing profile make blood-pool agents superior to standard agents for use in cerebral time-resolved MRA.

  View details for DOI 10.3174/ajnr.A3693

  View details for PubMedID 23969342

  View details for PubMedCentralID PMC7964731

• Initial experience with upfront arterial and perfusion imaging among ischemic stroke patients presenting within the 4.5-hour time window. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association Noorian, A. R., Bryant, K., Aiken, A., Nicholson, A. D., Edwards, A. B., Markowski, M. P., Dehkharghani, S., Bouloute, J. C., Abney, J., Nahab, F. 2014; 23 (2): 220-4

  Abstract

  Although perfusion imaging is being evaluated as a tool to select acute ischemic stroke patients who are most likely to benefit from reperfusion therapies beyond the standard time windows, there are limited data on the utility of perfusion imaging within the intravenous (IV) thrombolytic time window.A new stroke imaging protocol was initiated at Emory University Hospital including computed tomographic angiography (CTA) and computed tomographic perfusion (CTP). All patients presenting within 4.5 hours from last known normal time with suspected stroke were prospectively identified. Impact of CTA and CTP on the clinical management was recorded prospectively by stroke team members.During the study period, 87 patients met eligibility criteria for the CTA/CTP protocol, of which 83 (95%) underwent this upfront comprehensive imaging protocol and 30 (34%) received IV thrombolytics. Overall, stroke team members reported that CTA and/or CTP aided their clinical management in 39 (47%) cases, including aiding in identification of a nonstroke diagnosis (n = 18), triage to the neurologic intensive care unit (n = 9), early triage to endovascular therapy (n = 4), and initiation of IV thrombolytic for low National Institutes of Health Stroke Scale score with large vessel occlusion (n = 3). Door to needle time ≤60 minutes was achieved in only 18% of patients receiving IV thrombolysis during the study period, but had improved to 44% in the subsequent 6-month period.An upfront CTA/CTP protocol aided stroke team decision-making in nearly half of cases. Implementation of a CTA/CTP protocol was associated with a learning curve of 6 months before door to needle time ≤60 minutes returned to similar rates as the pre-CTA/CTP protocol.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2012.12.008

  View details for PubMedID 23352684

• Performance of spin-echo and gradient-echo T1-weighted sequences for evaluation of dural venous sinus thrombosis and stenosis. AJR. American journal of roentgenology Saindane, A. M., Mitchell, B. C., Kang, J., Desai, N. K., Dehkharghani, S. 2013; 201 (1): 162-9

  Abstract

  Dural venous sinus abnormalities are clinically important but can potentially be overlooked using various MRI techniques. This study evaluates the diagnostic accuracy of spin-echo (SE) T1-weighted imaging, 3D gradient-recalled echo (GRE) T1-weighted imaging, and contrast-enhanced MR venography (MRV) for the detection of dural venous sinus thrombosis and transverse sinus (TS) stenosis.Seventy-three patients underwent MRI evaluation with unenhanced and contrast-enhanced axial SE T1-weighted imaging, contrast-enhanced sagittal 3D GRE T1-weighted imaging, and contrast-enhanced MRV sequences. Three neuroradiologists each evaluated these 219 total datasets in a randomized blinded fashion for the presence or absence of TS stenosis and for dural venous sinus thrombosis in each of 10 venous sinus segments (730 total segments). Diagnostic performance characteristics and kappa statistics were calculated for each technique.Thirteen patients (37 segments) had suspected dural venous sinus thrombosis by one or more readers; of those 13 patients, nine (23 segments) were thought to have definite thrombosis on contrast-enhanced MRV. Compared with contrast-enhanced MRV, the positive predictive value (PPV) and negative predictive value (NPV) for thrombosis were 60% and 97%, respectively, for both unenhanced and contrast-enhanced SE T1-weighted imaging and 100% and 98% for 3D GRE T1-weighted imaging. Kappa values calculated per venous segment were as follows: 0.41 for SE T1-weighted imaging, 0.72 for 3D GRE T1-weighted imaging, and 0.95 for contrast-enhanced MRV. Thirty patients (58 segments) had TS stenosis suspected by one or more readers; of those 30 patients, TS stenosis was deemed to be definite on contrast-enhanced MRV in 25 patients (50 segments). Compared with contrast-enhanced MRV, the PPV and NPV were 75% and 80%, respectively, for SE T1-weighted imaging and 91% and 92% for 3D GRE T1-weighted imaging for the detection of stenosis. Kappa values calculated per patient were -0.038 for SE T1-weighted imaging, 0.58 for 3D GRE T1-weighted imaging, and 0.98 for contrast-enhanced MRV.Contrast-enhanced 3D GRE T1-weighted imaging is superior to SE T1-weighted imaging for the detection of dural venous sinus thrombosis and TS stenosis but does not substitute for dedicated MRV. Hyperintensity on unenhanced SE T1-weighted imaging is unreliable for the detection of dural venous sinus thrombosis.

  View details for DOI 10.2214/AJR.12.9095

  View details for PubMedID 23789671

• Unilateral Calcification of the Caudate and Putamen: Association with Underlying Developmental Venous Anomaly AMERICAN JOURNAL OF NEURORADIOLOGY Dehkharghani, S., Dillon, W. P., Bryant, S. O., Fischbein, N. J. 2010; 31 (10): 1848-1852

  Abstract

  Stenosis of a DVA may result in chronic venous ischemia. We present 6 patients (3 men, 3 women; age range, 30-79 years; mean age, 53 years) with unilateral calcification of the caudate and putamen on noncontrast CT. This calcification typically spared the anterior limb of the internal capsule. No patient presented with symptoms referable to the basal ganglia or had an underlying metabolic disorder or other process associated with calcium deposition. All patients subsequently underwent gadolinium-enhanced MR imaging and/or CTA or conventional angiography demonstrating the presence of an adjacent DVA. We hypothesize that chronic venous ischemia in the drainage territory of the DVA causes the abnormal mineralization. Greater recognition of this entity will prevent misinterpretation of this finding as acute hemorrhage and will prevent unnecessary and sometimes invasive evaluation in such patients. Furthermore, this entity should be considered in the differential diagnosis of unilateral basal ganglia hyperattenuation.

  View details for DOI 10.3174/ajnr.A2199

  View details for Web of Science ID 000285404300014

  View details for PubMedID 20634305

• Glutaraldehyde-induced and formaldehyde-induced allergic contact dermatitis among dental hygienists and assistants. Journal of the American Dental Association (1939) Ravis, S. M., Shaffer, M. P., Shaffer, C. L., Dehkharghani, S., Belsito, D. V. 2003; 134 (8): 1072-8

  Abstract

  Research has found that among health care workers, dental personnel are especially likely to have reactions to glutaraldehyde and formaldehyde.The authors conducted patch test evaluations with a voluntary cohort of randomly recruited, healthy dental hygienists, or DHs, and dental assistants, or DAs, and nondental professionals to determine the incidence of glutaraldehyde-induced and formaldehyde-induced allergic contact dermatitis, or ACD; the potential for coreactivity between glutaraldehyde and formaldehyde; and the correlation between training methods in safe handling of sterilizing solutions and the sensitivity to glutaraldehyde and formaldehyde among DHs and DAs.The researchers enrolled 101 DHs and DAs and 51 nondental professionals in the study. All except one DH/DA subject were female. The dental subjects' mean age was 34.3 +/- standard deviation of 10.7 years; the nondental subjects', 33.8 +/- 11.0 years. DHs and DAs had worked in their profession for a mean of 11.0 +/- 9.3 years. Among the dental professionals, 80 (79.2 percent) had had a known exposure to cold sterilizing solutions, while the remainder were unable to provide a known history of exposure. Eleven (10.9 percent) dental professionals had clear reactions to glutaraldehyde, four (4.0 percent) were questionably allergic to glutaraldehyde, and two (2 percent) were definitively allergic to formaldehyde. One (2 percent) control subject had a reaction to glutaraldehyde, and one other (2 percent) had a reaction to formaldehyde. CONCLUSIONS AND CLINICAL:The authors found a statistically significant disparity in the rates of glutaraldehyde sensitivity among healthy DHs and DAs versus healthy control subjects (10.9 percent versus 2 percent reactively; P = .02). They found no evidence of cross-reactivity between glutaraldehyde and formaldehyde. The preponderance of reactions among the DHs and DAs suggests that their present safety practices are largely ineffective in protecting against sensitization to glutaraldehyde in sterilizing solutions.

  View details for DOI 10.14219/jada.archive.2003.0321

  View details for PubMedID 12956347

• The economic burden of skin disease in the United States. Journal of the American Academy of Dermatology Dehkharghani, S., Bible, J., Chen, J. G., Feldman, S. R., Fleischer, A. B. 2003; 48 (4): 592-9

  Abstract

  Skin diseases and their complications are a significant burden on the nation, both in terms of acute and chronic morbidities and their related expenditures for care. Because accurately calculating the cost of skin disease has proven difficult in the past, we present here multiple comparative techniques allowing a more expanded approach to estimating the overall economic burden.Our aims were to (1) determine the economic burden of primary diseases falling within the realm of skin disease, as defined by modern clinical disease classification schemes and (2) identify the specific contribution of each component of costs to the overall expense.Costs were taken as the sum of several factors, divided into direct and indirect health care costs. The direct costs included inpatient hospital costs, ambulatory visit costs (further divided into physician's office visits, outpatient department visits, and emergency department visits), prescription drug costs, and self-care/over-the-counter drug costs. Indirect costs were calculated as the outlay of days of work lost because of skin diseases.The economic burden of skin disease in the United States is large, estimated at approximately $35.9 billion for 1997, including $19.8 billion (54%) in ambulatory care costs; $7.2 billion (20.2%) in hospital inpatient charges; $3.0 billion (8.2%) in prescription drug costs; $4.3 billion (11.7%) in over-the-counter preparations; and $1.6 billion (6.0%) in indirect costs attributable to lost workdays.Our determination of the economic burden of skin care in the United States surpasses past estimates several-fold, and the model presented for calculating cost of illness allows for tracking changes in national expenses for skin care in future studies. The amount of estimated resources devoted to skin disease management is far more than required to treat conditions such as urinary incontinence ($16 billion) and hypertension ($23 billion), but far less than required to treat musculoskeletal conditions ($193 billion).

  View details for DOI 10.1067/mjd.2003.178

  View details for PubMedID 12664024