Shashi Singh

All Publications

• Deep learning for accurate tumour volume measurement and prediction of therapy response in paediatric osteosarcoma. European radiology von Krüchten, R., Barrow, M., Adams, L., Singh, S. B., Varniab, Z. S., Suryadevara, V., Ghimire, P., Pribnow, A., Qi, J., Applin, D., Lokesha, Y. U., Nernekli, K., Daldrup-Link, H. E. 2025

  Abstract

  To assess treatment response in osteosarcoma, two automated convolutional neural networks (CNNs) were developed to quantify tumour volumes and predict response to induction chemotherapy using histopathology as the reference standard.This retrospective, multicentre study included magnetic resonance imaging (MRI) scans from osteosarcoma patients acquired between January 2006 and July 2024. A 3D U-Net CNN segmented tumours and calculated volumes at baseline and post-chemotherapy. A second CNN predicted treatment response based on MRI-derived tumour volume changes using histopathologic necrosis (≥ 90%) as the reference standard. Both models were trained on 162 scans from 81 patients (Centre A) and validated on 40 scans from 20 patients (10 per centre) with Centre B as the external test set. Human readers measured 3D tumour diameters and volumes, compared with CNN-derived volumes using Spearman's correlation, Bland-Altman plots, and Dice coefficients. Prediction performance was assessed using accuracy, sensitivity, and specificity, with significance determined by agreement metrics.Patients from Centre A had a mean age of 15 ± 5 years (52 males), and from Centre B a mean age of 13 ± 0 years (8 males). CNN- and human-derived tumour volumes showed strong correlation (Centre A: r = 0.98, Centre B: r = 0.95; p < 0.001). Dice coefficients were 0.86 (Centre A) and 0.81 (Centre B), with median Hausdorff distances of 15.0 mm and 14.2 mm. The response prediction model classified 16/20 cases (80% accuracy) with 90% sensitivity and 70% specificity.CNN-derived tumour volume measurements were comparable to human assessments. CNN-based volume changes predicted histopathologic response to chemotherapy in paediatric osteosarcoma.Question Accurate, noninvasive assessment of treatment response in paediatric osteosarcoma is limited by its reliance on manual tumour measurements and post-surgical histopathology. Findings Automated deep learning accurately measured tumour volumes on MRI and predicted chemotherapy response with 80% accuracy, 90% sensitivity, and 70% specificity. Clinical relevance Automated deep learning enables accurate tumour volume assessment and prediction of chemotherapy response in paediatric osteosarcoma, offering a noninvasive tool to support and refine patient management.

  View details for DOI 10.1007/s00330-025-12115-w

  View details for PubMedID 41176552

  View details for PubMedCentralID 4486345

• Apparent diffusion coefficient can assist in differentiating between benign and malignant primary bone tumors in pediatric patients. Skeletal radiology Lokesha, Y. U., Singh, S. B., von Krüchten, R., Varniab, Z. S., Kumar, M., Suryadevara, V., Sarrami, A. H., Liang, T., Wong, J., Pribnow, A., Daldrup-Link, H. E. 2025

  Abstract

  To evaluate differences in apparent diffusion coefficient (ADC) values between benign and malignant primary pediatric bone tumors and to assess their diagnostic accuracy in differentiating these tumors.We retrospectively analyzed MRI scans of 96 pediatric patients (54 males, 42 females; mean age 12.97 ± 3.9 years) with primary bone tumors who underwent diffusion-weighted imaging, including 48 benign and 48 malignant tumors. We measured ADCmean, ADCmin, and ADCmax of the solid tumor part, carefully avoiding cystic, necrotic, or sclerosed tumor areas. The Wilcoxon rank-sum test was used to test the distributional difference of benign vs malignant tumors. ROC curve analysis was performed to assess the diagnostic accuracy. The optimal cutoff of ADC values to differentiate benign and malignant bone tumors was defined as the point at which the Youden index, the sum of sensitivity and specificity, was maximized.The median values of the ADCmean, ADCmin, and ADCmax for benign bone tumors [1.34 (1.13-1.83), 0.98 (0.73-1.34), and 1.80 (1.57-2.46) × 10-3mm2/s, respectively] were significantly higher compared to malignant bone tumors [0.93 (0.78-1.03), 0.59 (0.43-0.72), and 1.35 (1.22-1.66) × 10-3mm2/s, respectively; all p < 0.05]. ADCmean yielded the highest diagnostic accuracy, with an optimal cutoff of 1.04 (0.94-1.15) × 10-3mm2/s (sensitivity 77%, specificity 93%, AUC = 0.91). An ADCmin cutoff of 0.82 (0.65-0.98) × 10-3mm2/s resulted in a sensitivity of 87.5%, specificity of 70.0%, and AUC of 0.85. An ADCmax cutoff of 1.48 (1.18-1.78) × 10-3mm2/s achieved a sensitivity of 68%, specificity of 81%, and AUC of 0.80.ADCmean, ADCmin, and ADCmax differ significantly between benign and malignant pediatric bone tumors, and the ADCmean provides the highest diagnostic accuracy.

  View details for DOI 10.1007/s00256-025-05060-8

  View details for PubMedID 41160129

  View details for PubMedCentralID 11099578

• B7-H4 ImmunoPET Imaging Tracks Tumor-Associated Macrophage Changes in Prostate Cancer. Molecular pharmaceutics Kumar, M., Singh, S. B., Vasyliv, I., Habte, F., Kalita, M., Alam, I. S., Koladiya, A., Dai, S. Y., James, M., Rao, J., Beziere, N., Daldrup-Link, H. E. 2025

  Abstract

  B7-H4 is an inhibitory immune checkpoint molecule that is upregulated in various cancers and correlates with advanced tumor stages and poor clinical outcomes. This study aimed to develop an immunoPET radiotracer for noninvasive assessment of B7-H4 expression in tumors and tumor-associated macrophages (TAM) and to evaluate the radiotracer potential to monitor therapeutic responses. We generated a B7-H4-targeted immunoPET imaging tracer by radiolabeling the anti-B7-H4 monoclonal antibody (2H9) with [89Zr], yielding [89Zr]Zr-DFO-2H9, and assessed its biodistribution in prostate cancer xenografts to quantitatively measure B7-H4 expression in vivo. In vitro binding studies confirmed the retained immunoreactivity and specificity for B7-H4. Radiochemical purity was verified using size exclusion chromatography. In vivo evaluation of [89Zr]Zr-DFO-2H9 was first performed in immunodeficient nude mice bearing subcutaneous DU145 human prostate tumors, with longitudinal PET imaging conducted over 7 days postinjection, followed by terminal biodistribution analysis. [89Zr]Zr-DFO-2H9 demonstrated a good tumor-binding profile and specificity in DU145 tumor xenografts. To distinguish PET signals from tumor cells versus macrophages, immunocompetent C57BL/6 mice bearing syngeneic TRAMP-C2 prostate tumors were divided into three cohorts and treated with PBS (control), cold anti-B7-H4 mAb (for B7-H4 blockade), or clodronate liposome (for macrophage depletion). In TRAMP-C2 tumors, the PET signal was significantly reduced in both the B7-H4 blocked and macrophage-depleted group compared to controls. Immunohistochemistry revealed that B7-H4 expression differences among TRAMP-C2 treatment groups were not as clearly distinguishable as those observed in vivo via PET imaging. Multiplexed immunofluorescence staining of macrophage markers indicated that infiltrating TAMs were the major contributors to B7-H4-specific PET signals within the tumor stroma. Collectively, these results show that [89Zr]Zr-DFO-2H9 binds B7-H4 with high affinity and specificity and reflects changes in TAM levels in vivo. The new radiotracer shows promise for detecting B7-H4 positive tumors and TAM levels, profiling the immune microenvironment, and monitoring macrophage-targeted immunotherapies.

  View details for DOI 10.1021/acs.molpharmaceut.5c00637

  View details for PubMedID 41122911

• [18F]NaF PET/CT Imaging of Iliac Bones to Assess Bone Turnover. Molecular imaging and biology Singh, S. B., Gandhi, O. H., Shrestha, B. B., Glennan, P., Bahadur, A. R., Motamedi, N., Khanal, K., Wagle, S., Høilund-Carlsen, P. F., Werner, T. J., Revheim, M. E., Alavi, A. 2025; 27 (3): 295-304

  Abstract

  This study investigated the effects of laterality, age, gender, BMI, and physical activity level on iliac bone turnover using [18F]NaF PET/CT.Fifty-nine males and 44 females from the CAMONA study were analyzed. A region of interest (ROI) was drawn to segment the iliac bone using Hounsfield unit thresholds and morphological closing algorithm. [18F]NaF SUVmean was compared between the left and right iliac bones using a paired t-test, while Pearson correlation coefficient assessed changes with age, BMI, and physical activity level.[18F]NaF uptake was higher in right iliac bone than left in males, females, and the combined-group. In males, SUVmean was 2.98 ± 1.63 (1.1-7.87) on left and 3.71 ± 1.49 (1.49-3.7) on right. In females, SUVmean was 2.59 ± 1.14 (0.88-6.27) on left and 3.72 ± 1.04 (2.22-6.51) on right. Combined, SUVmean was 2.81 ± 1.44 (0.88-7.87) on left and 3.71 ± 1.31 (0.89-8.07) on right. [18F]NaF uptake negatively correlated with age (right: r = - 0.27, P = 0.006; left: r = - 0.22, P = 0.02), stronger in females (right: r = - 0.30, P = 0.04; left: r = - 0.31, P = 0.04) than males (right: r = - 0.26, P = 0.04; left: r = - 0.18, P = 0.18). SUVmean correlated positively with BMI in males (right: r = 0.47, P = 0.0002; left: r = 0.38, P = 0.0027), females (right: r = 0.36, P = 0.0168; left: r = 0.30, P = 0.0505), and combined-group (right: r = 0.43, P < 0.0001; left: r = 0.37, P = 0.0001). No significant correlation was found between SUVmean and physical activity in males, while in females, a negative correlation was observed on left (r = - 0.37, P = 0.0390) but not on right (r = - 0.27, P = 0.1302), and when combined, the correlation remained significant on left (r = - 0.24, P = 0.0372) but not on right (r = - 0.16, P = 0.1541).[18F]NaF uptake was higher in the right iliac bone and declined with age, particularly in females. The positive correlation between SUVmean and BMI; and the negative correlation between SUVmean and physical activity suggest metabolic influences on bone turnover. [18F]NaF PET/CT may serve as a tool for assessing bone metabolism and turnover in asymptomatic individuals.

  View details for DOI 10.1007/s11307-025-02003-6

  View details for PubMedID 40274673

  View details for PubMedCentralID PMC12162772

• IDENTIFICATION OF SENESCENCE IN HUMAN OSTEOARTHRITIS TALUS JOINTS USING NOVEL IMAGING APPROACHES von Kruechten, R., Wrobel, S., Derycz, V., Lerner, C., Dreisbach, A. M., Meade, T., Oji, D., Singh, S., Varniab, Z., Tang, J., Gerencser, A., Suryadevara, V. ELSEVIER SCI LTD. 2025

  View details for Web of Science ID 001481830500054

• Improved Generalizability in Medical Computer Vision: Hyperbolic Deep Learning in Multi-Modality Neuroimaging. Journal of imaging Ayubcha, C., Sajed, S., Omara, C., Veldman, A. B., Singh, S. B., Lokesha, Y. U., Liu, A., Aziz-Sultan, M. A., Smith, T. R., Beam, A. 2024; 10 (12)

  Abstract

  Deep learning has shown significant value in automating radiological diagnostics but can be limited by a lack of generalizability to external datasets. Leveraging the geometric principles of non-Euclidean space, certain geometric deep learning approaches may offer an alternative means of improving model generalizability. This study investigates the potential advantages of hyperbolic convolutional neural networks (HCNNs) over traditional convolutional neural networks (CNNs) in neuroimaging tasks. We conducted a comparative analysis of HCNNs and CNNs across various medical imaging modalities and diseases, with a focus on a compiled multi-modality neuroimaging dataset. The models were assessed for their performance parity, robustness to adversarial attacks, semantic organization of embedding spaces, and generalizability. Zero-shot evaluations were also performed with ischemic stroke non-contrast CT images. HCNNs matched CNNs' performance in less complex settings and demonstrated superior semantic organization and robustness to adversarial attacks. While HCNNs equaled CNNs in out-of-sample datasets identifying Alzheimer's disease, in zero-shot evaluations, HCNNs outperformed CNNs and radiologists. HCNNs deliver enhanced robustness and organization in neuroimaging data. This likely underlies why, while HCNNs perform similarly to CNNs with respect to in-sample tasks, they confer improved generalizability. Nevertheless, HCNNs encounter efficiency and performance challenges with larger, complex datasets. These limitations underline the need for further optimization of HCNN architectures. HCNNs present promising improvements in generalizability and resilience for medical imaging applications, particularly in neuroimaging. Despite facing challenges with larger datasets, HCNNs enhance performance under adversarial conditions and offer better semantic organization, suggesting valuable potential in generalizable deep learning models in medical imaging and neuroimaging diagnostics.

  View details for DOI 10.3390/jimaging10120319

  View details for PubMedID 39728216

  View details for PubMedCentralID PMC11676359

• Applications of Artificial Intelligence for Pediatric Cancer Imaging. AJR. American journal of roentgenology Singh, S. B., Sarrami, A. H., Gatidis, S., Varniab, Z. S., Chaudhari, A., Daldrup-Link, H. E. 2024

  Abstract

  Artificial intelligence (AI) is transforming medical imaging of adult patients. However, its utilization in pediatric oncology imaging remains constrained, in part due to the inherent data scarcity associated with childhood cancers. Pediatric cancers are rare, and imaging technologies are evolving rapidly, leading to insufficient data of a particular type to effectively train these algorithms. The small market size of pediatrics compared to adults could also contribute to this challenge, as market size is a driver of commercialization. This article provides an overview of the current state of AI applications for pediatric cancer imaging, including applications for medical image acquisition, processing, reconstruction, segmentation, diagnosis, staging, and treatment response monitoring. While current developments are promising, impediments due to diverse anatomies of growing children and nonstandardized imaging protocols have led to limited clinical translation thus far. Opportunities include leveraging reconstruction algorithms to achieve accelerated low-dose imaging and automating the generation of metric-based staging and treatment monitoring scores. Transfer-learning of adult-based AI models to pediatric cancers, multi-institutional data sharing, and ethical data privacy practices for pediatric patients with rare cancers will be keys to unlocking AI's full potential for clinical translation and improved outcomes for these young patients.

  View details for DOI 10.2214/AJR.24.31076

  View details for PubMedID 38809123

• PET/CT in the Evaluation of CAR-T Cell Immunotherapy in Hematological Malignancies. Molecular imaging Singh, S. B., Bhandari, S., Siwakoti, S., Kumar, M., Singh, R., Bhusal, S., Sharma, K., Bhandari, S., Khanal, K. 2024; 23: 15353508241257924

  Abstract

  Chimeric antigen receptor (CAR)-T cell-based immunotherapy has emerged as a path-breaking strategy for certain hematological malignancies. Assessment of the response to CAR-T therapy using quantitative imaging techniques such as positron emission tomography/computed tomography (PET/CT) has been broadly investigated. However, the definitive role of PET/CT in CAR-T therapy remains to be established. [18F]FDG PET/CT has demonstrated high sensitivity and specificity for differentiating patients with a partial and complete response after CAR-T therapy in lymphoma. The early therapeutic response and immune-related adverse effects such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome can also be detected on [18F]FDG PET images. In otherwise asymptomatic lymphoma patients with partial response following CAR-T therapy, the only positive findings could be abnormal PET/CT results. In multiple myeloma, a negative [18F]FDG PET/CT after receiving B-cell maturation antigen-directed CAR-T therapy has been associated with a favorable prognosis. In leukemia, [18F]FDG PET/CT can detect extramedullary metastases and treatment responses after therapy. Hence, PET/CT is a valuable imaging tool for patients undergoing CAR-T therapy for pretreatment evaluation, monitoring treatment response, assessing safety, and guiding therapeutic strategies. Developing guidelines with standardized cutoff values for various PET parameters and tumor cell-specific tracers may improve the efficacy and safety of CAR-T therapy.

  View details for DOI 10.1177/15353508241257924

  View details for PubMedID 38952399

  View details for PubMedCentralID PMC11208886

• Detecting High-Dose Methotrexate-Induced Brain Changes in Pediatric and Young Adult Cancer Survivors Using [18F]FDG PET/MRI: A Pilot Study. Journal of nuclear medicine : official publication, Society of Nuclear Medicine Baratto, L., Singh, S. B., Williams, S. E., Spunt, S. L., Rosenberg, J., Adams, L., Suryadevara, V., Iv, M., Daldrup-Link, H. 2024

  Abstract

  Significant improvements in treatments for children with cancer have resulted in a growing population of childhood cancer survivors who may face long-term adverse outcomes. Here, we aimed to diagnose high-dose methotrexate-induced brain injury on [18F]FDG PET/MRI and correlate the results with cognitive impairment identified by neurocognitive testing in pediatric cancer survivors. Methods: In this prospective, single-center pilot study, 10 children and young adults with sarcoma (n = 5), lymphoma (n = 4), or leukemia (n = 1) underwent dedicated brain [18F]FDG PET/MRI and a 2-h expert neuropsychologic evaluation on the same day, including the Wechsler Abbreviated Scale of Intelligence, second edition, for intellectual functioning; Delis-Kaplan Executive Function System (DKEFS) for executive functioning; and Wide Range Assessment of Memory and Learning, second edition (WRAML), for verbal and visual memory. Using PMOD software, we measured the SUVmean, cortical thickness, mean cerebral blood flow (CBFmean), and mean apparent diffusion coefficient of 3 different cortical regions (prefrontal cortex, cingulate gyrus, and hippocampus) that are routinely involved during the above-specified neurocognitive testing. Standardized scores of different measures were converted to z scores. Pairs of multivariable regression models (one for z scores < 0 and one for z scores > 0) were fitted for each brain region, imaging measure, and test score. Heteroscedasticity regression models were used to account for heterogeneity in variances between brain regions and to adjust for clustering within patients. Results: The regression analysis showed a significant correlation between the SUVmean of the prefrontal cortex and cingulum and DKEFS-sequential tracking (DKEFS-TM4) z scores (P = 0.003 and P = 0.012, respectively). The SUVmean of the hippocampus did not correlate with DKEFS-TM4 z scores (P = 0.111). The SUVmean for any evaluated brain regions did not correlate significantly with WRAML-visual memory (WRAML-VIS) z scores. CBFmean showed a positive correlation with SUVmean (r = 0.56, P = 0.01). The CBFmean of the cingulum, hippocampus, and prefrontal cortex correlated significantly with DKEFS-TM4 (all P < 0.001). In addition, the hippocampal CBFmean correlated significantly with negative WRAML-VIS z scores (P = 0.003). Conclusion: High-dose methotrexate-induced brain injury can manifest as a reduction in glucose metabolism and blood flow in specific brain areas, which can be detected with [18F]FDG PET/MRI. The SUVmean and CBFmean of the prefrontal cortex and cingulum can serve as quantitative measures for detecting executive functioning problems. Hippocampal CBFmean could also be useful for monitoring memory problems.

  View details for DOI 10.2967/jnumed.123.266760

  View details for PubMedID 38575193

• Machine learning in the positron emission tomography imaging of Alzheimer's disease. Nuclear medicine communications Ayubcha, C., Singh, S. B., Patel, K. H., Rahmim, A., Hasan, J., Liu, L., Werner, T., Alavi, A. 2023

  Abstract

  The utilization of machine learning techniques in medicine has exponentially increased over the last decades due to innovations in computer processing, algorithm development, and access to big data. Applications of machine learning techniques to neuroimaging specifically have unveiled various hidden interactions, structures, and mechanisms related to various neurological disorders. One application of interest is the imaging of Alzheimer's disease, the most common cause of progressive dementia. The diagnoses of Alzheimer's disease, mild cognitive impairment, and preclinical Alzheimer's disease have been difficult. Molecular imaging, particularly via PET scans, holds tremendous value in the imaging of Alzheimer's disease. To date, many novel algorithms have been developed with great success that leverage machine learning in the context of Alzheimer's disease. This review article provides an overview of the diverse applications of machine learning to PET imaging of Alzheimer's disease.

  View details for DOI 10.1097/MNM.0000000000001723

  View details for PubMedID 37395538

• Multimodal Pediatric Lymphoma Detection using PET and MRI. AMIA ... Annual Symposium proceedings. AMIA Symposium Wang, H., Sarrami, A., Wu, J. T., Baratto, L., Sharma, A., Wong, K. C., Singh, S. B., Daldrup-Link, H. E., Syeda-Mahmood, T. 2023; 2023: 736-743

  Abstract

  Lymphoma is one of the most common types of cancer for children (ages 0 to 19). Due to the reduced radiation exposure, PET/MR systems that allow simultaneous PET and MR imaging have become the standard of care for diagnosing cancers and monitoring tumor response to therapy in the pediatric population. In this work, we developed a multimodal deep learning algorithm for automatic pediatric lymphoma detection using PET and MRI. Through innovative designs such as standardized uptake value (SUV) guided tumor candidate generation, location aware classification model learning and weighted multimodal feature fusion, our algorithm can be effectively trained with limited data and achieved superior tumor detection performance over the state-of-the-art in our experiments.

  View details for PubMedID 38222333

  View details for PubMedCentralID PMC10785920

• Somatostatin receptor PET-guided treatment and artificial intelligence applications in meningioma: a comprehensive review. American journal of nuclear medicine and molecular imaging Gujral, J., Gandhi, O. H., Amanullah, A. A., Singh, S. B., Ayubcha, C., Werner, T. J., Revheim, M. E., Alavi, A. 2025; 15 (6): 223-235

  Abstract

  Meningiomas are the most common primary intracranial tumors, with treatment involving resection and radiation therapy. However, therapeutic options are limited for recurrent or progressive disease, particularly in higher World Health Organization (WHO) grade tumors. Somatostatin receptor (SSTR) expression in meningiomas has opened new therapeutic opportunities as the differential SSTR2 overexpression permits molecular targeting using radiolabeled somatostatin analogs. PRRT offers promising therapeutic efficacy in select meningioma patients, with clinical responses strongly correlated to WHO tumor grade and SSTR expression levels. Combining SSTR PET imaging, to evaluate receptor density, with radiomic analysis can reveal tumor heterogeneity patterns and quantitative imaging features that can guide clinical decision-making and monitor treatment response. Integrating machine learning and artificial intelligence (AI) into clinical workflows offer novel approaches to apply quantitative SUV parameters, image texture features, and histopathologic data in order to identify patients with WHO grade II and III meningiomas at greater risk of tumor recurrence. Given the heterogeneity in imaging and treatment protocols across institutions and the limited number of PRRT-treated meningioma cohorts, future research should prioritize prospective, multicenter studies that integrate histologic and molecular imaging data to refine patient selection strategies and establish PRRT's role within personalized, precision cancer treatment paradigms.

  View details for DOI 10.62347/LYAT6783

  View details for PubMedID 41567833

  View details for PubMedCentralID PMC12816823

• The Genetics of Amyloid Deposition: A Systematic Review of Genome-Wide Association Studies Using Amyloid PET Imaging in Alzheimer's Disease. Journal of imaging Amanullah, A. A., Mirbod, M., Pandey, A., Singh, S. B., Gandhi, O. H., Ayubcha, C. 2025; 11 (8)

  Abstract

  Positron emission tomography (PET) has become a powerful tool in Alzheimer's disease (AD) research by enabling in vivo visualization of pathological biomarkers. Recent efforts have aimed to integrate PET-derived imaging phenotypes with genome-wide association studies (GWASs) to better elucidate the genetic architecture underlying AD. This systematic review examines studies that leverage PET imaging in the context of GWASs (PET-GWASs) to identify genetic variants associated with disease risk, progression, and brain region-specific pathology. A comprehensive search of PubMed and Embase databases was performed on 18 February 2025, yielding 210 articles, of which 10 met pre-defined inclusion criteria and were included in the final synthesis. Studies were eligible if they included AD populations, employed PET imaging alongside GWASs, and reported original full-text findings in English. No formal protocol was registered, and the risk of bias was not independently assessed. The included studies consistently identified APOE as the strongest genetic determinant of amyloid burden, while revealing additional significant loci including ABCA7 (involved in lipid metabolism and amyloid clearance), FERMT2 (cell adhesion), CR1 (immune response), TOMM40 (mitochondrial function), and FGL2 (protective against amyloid deposition in Korean populations). The included studies suggest that PET-GWAS approaches can uncover genetic loci involved in processes such as lipid metabolism, immune response, and synaptic regulation. Despite limitations including modest cohort sizes and methodological variability, this integrated approach offers valuable insight into the biological pathways driving AD pathology. Expanding PET-genomic datasets, improving study power, and applying advanced computational tools may further clarify genetic mechanisms and contribute to precision medicine efforts in AD.

  View details for DOI 10.3390/jimaging11080280

  View details for PubMedID 40863490

  View details for PubMedCentralID PMC12387344

• Application of [18F]-fluorodeoxyglucose PET/computed tomography to measure volume and metabolic activity of arm muscles. Nuclear medicine communications Ahmed, M., Gandhi, O. H., Singh, S. B., Gujral, J., Park, P. K., Shrestha, B. B., Niazi, S. K., Ismoilov, M., Motamedi, N., Werner, T. J., Revheim, M. E., Alavi, A. 2025

  Abstract

  This study aimed to introduce a computed tomography (CT)-based tissue segmentation technique to quantify the volume and metabolic activity of the arm muscles using [18F]-fluorodeoxyglucose ([18F]FDG) PET/CT.Eighty-seven subjects from the CAMONA study were included. A semiautomated three-dimensional segmentation algorithm was used to highlight the muscle. The [18F]FDG uptake was measured as mean standardized uptake value (SUV) normalized to body weight (SUVBW) and to lean body mass (SUVLBM). To acquire normalized volume, arm muscle volume, humerus volume, and humerus length were used. The average SUVmean was calculated from independently measured volumes (cm3) of the left and right muscle groups. The obtained SUVBW, SUVLBM, and normalized volume were used to compare the right and left arms.Between right and left arm muscles, there was significantly higher uptake of SUVBW and SUVLBM in the right arm compared with the left (P < 0.001). Between males and females, there was a significantly higher SUVBW in the right arm for females (P = 0.03) and significantly higher normalized volume on both right and left arms for males (right, P < 0.001; left, P < 0.001).[18F]FDG PET/CT using CT-based segmentation enables analysis of total arm muscle metabolic activity and volume. This methodology demonstrated significant differences in mean SUVBW and SUVLBM between the left and right arms, with consistently higher uptake in the right arm. In addition, females exhibited higher SUVBW than males. The techniques developed in this study may also be applied to further investigate the laterality and metabolism of other muscle groups.

  View details for DOI 10.1097/MNM.0000000000002038

  View details for PubMedID 40791014

• Maxillary sinus inflammation assessment using FDG-PET/CT in head and neck cancer patients with photon, proton, and combined radiation therapy. American journal of nuclear medicine and molecular imaging Gandhi, O. H., Lee, A. E., Gujral, J., Ismoilov, M., Singh, S. B., Ghonim, M., Ghonim, M., Kim, M. Y., Raynor, W. Y., Case, M. J., Siddiqi, A., Yazdanpanah, F., Werner, T. J., Saboury, B., Revheim, M. E., Chang, Y. C., Alavi, A. 2025; 15 (3): 97-104

  Abstract

  Head and neck cancer (HNC) patients frequently develop post-radiation maxillary sinusitis. This study investigated how different radiation therapy (RT) modalities, photon, proton, and mixed photon/proton RT, affect maxillary sinus inflammation, using 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT).Seventy-seven HNC patients treated with RT (30 with photon, 20 with proton, and 27 with mixed photon/proton RT) underwent FDG-PET/CT imaging before and 3 months after treatment. Demographic information, tumor location, chemotherapy details, radiation dose (cGy), and post-radiation sinusitis ratings (scale 0-2) were collected. The mean standardized uptake value (SUVmean) of the maxillary sinus was measured by a radiologist with two years of experience using manually delineated regions of interest. Parametric paired t-tests were used to compare pre- and post-treatment SUVmeans for each RT modality. Pre-minus-post-treatment changes in SUVmean (ΔSUVmean) between RT modalities were compared using independent t-tests. Correlation between radiation dose and ΔSUVmean and correlation between ΔSUVmean and clinical sinusitis scores were assessed using Pearson correlation analysis.Photon RT was associated with a statistically significant increase in maxillary sinus SUVmean post-treatment (+14.32%, P = 0.0324), while proton RT and mixed photon/proton RT did not result in significant changes (-3.39%, P = 0.6549 and -5.33%, P = 0.4541, respectively). A significant difference was found between photon and mixed photon/proton RT (P = 0.0444), whereas the difference between photon and proton RT approached significance (P = 0.0790). Clinical inflammation ratings were highest for photon therapy (average 0.97), followed by mixed therapy (0.78), then proton therapy (0.65), though these differences were not statistically significant.Our findings demonstrate that photon RT leads to significant increases in maxillary sinus SUVmean as measured by FDG-PET/CT, while proton and mixed photon/proton RT do not show statistically significant changes. These preliminary results suggest that proton-based radiation modalities may be associated with reduced maxillary sinus inflammatory activity compared to photon RT alone, though larger studies with longer follow-up are needed to establish clinical significance and patient outcomes.

  View details for DOI 10.62347/GLDL6616

  View details for PubMedID 40688536

  View details for PubMedCentralID PMC12267090

• Evolving Role of PET/MRI in Oropharyngeal Cancers Baral, M., Bhandari, S., Bhandari, S., Bhandari, S., Singh, C., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549722900016

• Emerging Role of FAPI-PET/CT in the Imaging of Interstitial Lung Diseases Bhattarai, B., Gnawali, A., Bhandari, S., Singh, C., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545742900018

• Role of Fibroblast Activation Protein Inhibitor (FAPI)-based PET radiotracers in Rheumatoid Arthritis Bhattarai, B., Singh, C., Gandhi, O., Gujral, K., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545742900046

• An Overview on Current Large Axial Field of View Scanners Gujral, K., Gujral, J., Gandhi, O., Singh, S., Ayubcha, C., Werner, T., Revheim, M., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545700600011

• Alpha-Synuclein PET Tracers in Synucleinopathies Gujral, J., Gandhi, O., Singh, S., Ayubcha, C., Werner, T., Revheim, M., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545700600027

• Highlights on Large Axial Field of View Scanners Currently Under Development Gujral, K., Gujral, J., Gandhi, O., Singh, S., Ayubcha, C., Werner, T., Revheim, M., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545700600003

• Genome-Wide Association Studies of PET Neuroimaging Identify the Genetic Mechanisms of Alzheimer's Disease Pathophysiology Pandey, A., Singh, S., Chaudhary, S., Gandhi, O., Werner, T., Alavi, A., Ayubcha, C. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545742900024

• Dual time-point imaging of liver and spleen in patients with lymphoma using total-body FDG PET/CT Gujral, J., Singh, S., Gandhi, O., Gujral, K., Ayubcha, C., Motamedi, N., Shrestha, B., Werner, T., Revheim, M., Nardo, L., Abdelhafez, Y., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001567002900045

• Metabolic Irregularities Associated with Depression in Alzheimer's Patients: Insights from [18F] FDG PET/CT Imaging Khan, T., Patil, S., Subtirelu, R., Khan, F., Ayubcha, C., Revheim, M., Singh, S., Werner, T., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001567002900021

• Molecular Imaging with the Genetics of Neurological Diseases Gujral, J., Gandhi, O., Singh, S., Pandey, A., Ayubcha, C., Werner, T., Revheim, M., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001567002900002

• Integrating MRI PI-RADS and PSMA-PET PRIMARY Scores: P Score for Enhanced Prostate Cancer Diagnosis Moradpour, M., Gandhi, O., Singh, S., Werner, T., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549722900028

• FAPI PET/CT for assessment of interstitial lung disease Khadka, A., Singh, C., Gujral, K., Bhandari, S., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549722900001

• Targeted Radiotracers in Oncology: Evaluating the Potential of 68GaNeoB in Prostate Cancer Pandey, A., Chaudhary, S., Singh, C., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300019

• Molecular Imaging for Cardiac Amyloidosis: Opportunities and Challenges Pandey, A., Chaudhary, S., Singh, C., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300018

• FAPI PET/CT for Imaging Renal Cancers Pandey, A., Chaudhary, S., Singh, C., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300020

• The Role of FDG-PET Imaging in Detecting and Monitoring Neurological Involvement in Systemic Lupus Erythematosus (SLE) Moradpour, M., Gujral, J., Gandhi, O., Singh, S., Werner, T., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549722900025

• Role of PET to Evaluate Kidney Transplantation Complications Pandey, A., Chaudhary, S., Singh, C., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300027

• PET Imaging in Renal Inflammation: Insights into Diagnosis and Disease Progression Pandey, A., Chaudhary, S., Singh, C., Gujral, K., Gandhi, O., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300043

• Evaluating Immunotherapy Response in Melanoma Patients Using Total Body PET/CT Moradpour, M., Rokni, M., Mhana, S., Gandhi, O., Singh, S., Werner, T., Abdelhafez, Y., Nardo, L., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001549823300036

• PET radiotracers other than 18F-FDG for assessment of chimeric antigen receptor T-cell (CAR-T) therapy Singh, C., Baral, M., Bhandari, S., Bhattarai, B., Pandey, A., Siwakoti, S., Singh, S. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001537713700016

• Meeting ReportEDU: Neurosciences Treatment-Refractory Meningioma: Somatostatin Receptor-Targeted Radiopeptide Therapy Gujral, J., Gandhi, O., Singh, S., Ayubcha, C., Werner, T., Revheim, M., Alavi, A. SOC NUCLEAR MEDICINE INC. 2025

  View details for Web of Science ID 001545700600047

• A Brief History and the Use of PET in the Diagnosis and Management of Schizophrenia: An Educational Review. PET clinics Singh, S. B., Bhattarai, Y., Kafle, R., Panta, M., Tiwari, A., Ayubcha, C., Werner, T. J., Alavi, A., Revheim, M. E. 2024

  Abstract

  This article explores the role of PET in the diagnosis and treatment of schizophrenia. PET imaging can reveal neurobiologic aspects such as cerebral blood flow, glucose metabolism, receptor function, and neuroinflammation in schizophrenia. It has supported the dopaminergic hypothesis and helped distinguish symptom types and severity. Diagnostic biomarkers from PET could differentiate schizophrenia from other disorders, while predictive biomarkers might allow earlier targeted treatments. Despite significant promises, the application of PET imaging in schizophrenia is still in its nascent stage, requiring well-designed multicenter studies with large sample sizes to fully realize its clinical potential.

  View details for DOI 10.1016/j.cpet.2024.09.005

  View details for PubMedID 39477720

• The comparative utility of FAPI-based PET radiotracers over [18F]FDG in the assessment of malignancies. American journal of nuclear medicine and molecular imaging Singh, S. B., Shrestha, B. B., Gandhi, O. H., Shah, R. P., Mukhtiar, V., Ayubcha, C., Desai, V., Eberts, C. E., Paudyal, P., Jha, G., Singh, A., Shi, Y., Kumar, T. 2024; 14 (4): 190-207

  Abstract

  Fibroblast activation protein (FAP) is a type II transmembrane serine protease overexpressed in cancer-associated fibroblasts (CAFs) and has been associated with poor prognosis. PET/CT imaging with radiolabeled FAP inhibitors (FAPI) is currently being studied for various malignancies. This review identifies the uses and limitations of FAPI PET/CT in malignancies and compares the advantages and disadvantages of FAPI and 18F-fluorodeoxyglucose ([18F]FDG). Due to high uptake, rapid clearance from the circulation, and limited uptake in normal tissue, FAPI tumor-to-background contrast ratios are equivalent to or better than [18F]FDG in most applications. In several settings, FAPI has shown greater uptake specificity than [18F]FDG and improved sensitivity in detecting lymph node, bone, and visceral tissue metastases. Therefore, FAPI PET/CT may be complementary in distinguishing pathological lesions with conventional imaging, determining the primary site of malignancy, improving tumor staging, and detecting disease recurrence, especially in patients with inconclusive [18F]FDG PET/CT findings. Nevertheless, FAPI has limitations, including certain settings with non-specific uptake, modified uptake with age and menopause status, challenges with clinical access, and limited clinical evidence.

  View details for DOI 10.62347/JXZI9315

  View details for PubMedID 39309420

  View details for PubMedCentralID PMC11411191

• PET Imaging in Chimeric Antigen Receptor T-Cell Trafficking. PET clinics Glennan, P., Shehu, V., Singh, S. B., Werner, T. J., Alavi, A., Revheim, M. E. 2024

  Abstract

  The evolving field of chimeric antigen receptor (CAR) T-cell therapy, though promising, necessitates more comprehensive imaging methods to enhance therapeutic effectiveness and track cell trafficking in patients and ex vivo. This review examines the application of PET imaging in CAR T-cell trafficking and optimizing their therapeutic impact. The application of PET imaging using various radiotracers is promising in providing evaluation of CAR T-cell interaction within the host, thereby facilitating strategies for improved patient outcomes. As this technology progresses, further innovative strategies to streamline assessments of immunotherapeutic effectiveness are anticipated.

  View details for DOI 10.1016/j.cpet.2024.06.002

  View details for PubMedID 38987123

• Advancements in Aortic Stenosis Imaging: The Emerging Role of PET/CT and PET/MRI Khanal, K., Singh, A., Ashfaq, F., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601008

• Advancing the Detection of Cardiac Allograft Vasculopathy: The Role of PET/CT Imaging in Post-Heart Transplant Patients Khanal, K., Singh, A., Ashfaq, F., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601012

• Assessing the Role of 18F-FDG PET/CT in the Diagnosis and Prognosis of Cardiac Tumors Khanal, K., Khadka, A., Singh, A., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601013

• Diagnostic and Prognostic Potential of 68Ga-FAPI PET/CT in Cardiac Imaging Khanal, K., Shah, R., Singh, A., Ashfaq, F., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601014

• Enhancing the Diagnosis of Infective Endocarditis: The Role of 18F-FDG PET/CT Khanal, K., Siwakoti, S., Singh, A., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601009

• Advancements in Myocardial Viability Assessment and Its Impact on Treatment Strategies for Post-Revascularization Recovery Khanal, K., Singh, A., Ashfaq, F., Singh, S. SOC NUCLEAR MEDICINE INC. 2024

  View details for Web of Science ID 001289165601157

• [18F]FDG PET/CT for identifying the causes of fever of unknown origin (FUO). American journal of nuclear medicine and molecular imaging Singh, S. B., Shrestha, N., Bhandari, S., Shrestha, S., Shrestha, B., Shrestha, N., Rijal, S., Singh, R., Hess, S., Werner, T. J., Alavi, A., Revheim, M. E. 2024; 14 (2): 87-96

  Abstract

  Fever of unknown origin (FUO) continues to be a challenging diagnosis in clinical medicine. It has more than 200 known causes, including infections, autoimmune diseases, neoplasia, and other miscellaneous disorders. Despite the development of a wide range of diagnostic tools, a specific diagnostic algorithm for FUO is not yet available. However, [18F]FDG PET/CT, which yields information on cellular metabolism, in addition to details of organ anatomy, has been shown to be successful in the FUO investigation. This study highlights the uses of [18F]FDG PET/CT in diagnosing various causes of FUO. [18F]FDG PET/CT has been increasingly used to detect septic infections, sterile inflammatory processes, and malignancies, occupying a significant portion of the known causes of FUO. It has led to a more definitive identification of the etiology of FUO and accurate clinical management. However, more in-depth studies are crucial to understanding if [18F]FDG PET/CT can be used in the work-up of FUO.

  View details for DOI 10.62347/OQQC6007

  View details for PubMedID 38737639

  View details for PubMedCentralID PMC11087293

• The utility of PET imaging in depression. Frontiers in psychiatry Singh, S. B., Tiwari, A., Katta, M. R., Kafle, R., Ayubcha, C., Patel, K. H., Bhattarai, Y., Werner, T. J., Alavi, A., Revheim, M. E. 2024; 15: 1322118

  Abstract

  This educational review article aims to discuss growing evidence from PET studies in the diagnosis and treatment of depression. PET has been used in depression to explore the neurotransmitters involved, the alterations in neuroreceptors, non-neuroreceptor targets (e.g., microglia and astrocytes), the severity and duration of the disease, the pharmacodynamics of various antidepressants, and neurobiological mechanisms of non-pharmacological therapies like psychotherapy, electroconvulsive therapy, and deep brain stimulation therapy, by showing changes in brain metabolism and receptor and non-receptor targets. Studies have revealed alterations in neurotransmitter systems such as serotonin, dopamine, GABA, and glutamate, which are linked to the pathophysiology of depression. Overall, PET imaging has furthered the neurobiological understanding of depression. Despite these advancements, PET findings have not yet led to significant changes in evidence-based practices. Addressing the reasons behind inconsistencies in PET imaging results, conducting large sample size studies with a more standardized methodological approach, and investigating further the genetic and neurobiological aspects of depression may better leverage PET imaging in future studies.

  View details for DOI 10.3389/fpsyt.2024.1322118

  View details for PubMedID 38711875

  View details for PubMedCentralID PMC11070570

• Molecular Imaging Techniques in the Diagnosis and Monitoring of Infectious Diseases CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES Thorsen, M., Singh, S. B., Rewers, K., Werner, T. J., Alavi, A., Hess, S. 2024

  View details for DOI 10.1007/s40506-024-00274-1

  View details for Web of Science ID 001195684500001

• Role of PET/CT in diagnosing and monitoring disease activity in rheumatoid arthritis: a review. Annals of nuclear medicine Singh, S. B., Bhandari, S., Bhandari, S., Bhandari, S., Singh, R., Raynor, W. Y., Hess, S., Werner, T. J., Alavi, A., Revheim, M. 2024

  Abstract

  Rheumatoid Arthritis (RA) is a systemic inflammatory disorder that commonly presents with polyarthritis but can have multisystemic involvement and complications, leading to increased morbidity and mortality. The diagnosis of RA continues to be challenging due to its varied clinical presentations. In this review article, we aim to determine the potential of PET/CT to assist in the diagnosis of RA and its complications, evaluate the therapeutic response to treatment, and predict RA remission. PET/CT has increasingly been used in the last decade to diagnose, monitor treatment response, predict remissions, and diagnose subclinical complications in RA. PET imaging with [18F]-fluorodeoxyglucose ([18F]-FDG) is the most commonly applied radiotracer in RA, but other tracers are also being studied. PET/CT with [18F]-FDG, [18F]-NaF, and other tracers might lead to early identification of RA and timely evidence-based clinical management, decreasing morbidity and mortality. Although PET/CT has been evolving as a promising tool for evaluating and managing RA, more evidence is required before incorporating PET/CT in the standard clinical management of RA.

  View details for DOI 10.1007/s12149-023-01896-z

  View details for PubMedID 38277115

• A Cross-Sectional Study Examining Hyoid Bone Fusion and Density Variation among Patients Receiving Care at a Tertiary Hospital Journal of Evolution of Medical and Dental Sciences Lokesha, Y. U., Kamireddy, A., Singh, S. B., Srinivasa, M., G., R. D., Bhat, R. R., Srinivas, D. 2024: 85-91

  View details for DOI 10.14260/jemds.v13i4.606

• PET, SPECT, and MRI imaging for evaluation of Parkinson's disease. American journal of nuclear medicine and molecular imaging Gujral, J., Gandhi, O. H., Singh, S. B., Ahmed, M., Ayubcha, C., Werner, T. J., Revheim, M., Alavi, A. 2024; 14 (6): 371-390

  Abstract

  This review assesses the primary neuroimaging techniques used to evaluate Parkinson's disease (PD) - a neurological condition characterized by gradual dopamine-producing nerve cell degeneration. The neuroimaging techniques explored include positron emission tomography (PET), single-photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). These modalities offer varying degrees of insights into PD pathophysiology, diagnostic accuracy, specificity by way of exclusion of other Parkinsonian syndromes, and monitoring of disease progression. Neuroimaging is thus crucial for diagnosing and managing PD, with integrated multimodal approaches and novel techniques further enhancing early detection and treatment evaluation.

  View details for DOI 10.62347/AICM8774

  View details for PubMedID 39840378

• Neurological and Psychiatric Manifestations of Long COVID-19 and Their [18F]FDG PET Findings: A Review. Diagnostics (Basel, Switzerland) Hameed, R., Bahadur, A. R., Singh, S. B., Sher, J., Todua, M., Moradi, L. M., Bastakoti, S., Arslan, M., Ajmal, H., Lee, G. Y., Ayubcha, C., Werner, T. J., Alavi, A., Revheim, M. E. 2023; 13 (14)

  Abstract

  For more than two years, lingering sequalae of COVID-19 have been extensively investigated. Approximately 10% of individuals infected by COVID-19 have been found to experience long-term symptoms termed "long COVID-19". The neurological and psychiatric manifestations of long COVID-19 are of particular concern. While pathogenesis remains unclear, emerging imaging studies have begun to better elucidate certain pathological manifestation. Of specific interest is imaging with [18F]FDG PET which directly reflects cellular glycolysis often linked to metabolic and inflammatory processes. Seeking to understand the molecular basis of neurological features of long COVID-19, this review encompasses the most recent [18F]FDG PET literature in this area.

  View details for DOI 10.3390/diagnostics13142353

  View details for PubMedID 37510097

• Is Imaging Bacteria with PET a Realistic Option or an Illusion? Diagnostics (Basel, Switzerland) Singh, S. B., Bhandari, S., Siwakoti, S., Bhatta, R., Raynor, W. Y., Werner, T. J., Alavi, A., Hess, S., Revheim, M. E. 2023; 13 (7)

  Abstract

  The application of [18F]-fluorodeoxyglucose ([18F]FDG) as a radiotracer to detect sites of inflammation (either due to bacterial infection or primary inflammation) has led to exploring the role of PET in visualizing bacteria directly at sites of infection. However, the results from such efforts are controversial and inconclusive so far. We aimed to assess the limitations of PET as an effective modality in the diagnosis of bacterial infections. Inflammation due to bacterial infections can be visualized by using [18F]FDG-PET. However, the non-specificity of [18F]FDG makes it undesirable to visualize bacteria as the underlying cause of inflammation. Hence, more specific radiotracers that possibly bind to or accumulate in bacteria-specific receptors or enzymes are being explored. Several radiotracers, including 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS), 6-[18F]-fluoromaltose, [11C]para-aminobenzoic acid ([11C]PABA), radiolabeled trimethoprim (11C-TMP) and its analog fluoropropyl-trimethoprim (18F-FPTMP), other radiolabeled sugars, and antimicrobial drugs have been used to image microorganisms. Unfortunately, no progress has been made in translating the results to routine human use; feasibility and other factors have constrained their success in clinical settings. In the current article, we discuss the limitations of direct bacterial visualization with PET tracers, but emphasize the important role of [18F]FDG-PET as the only option for detecting evidence of infection.

  View details for DOI 10.3390/diagnostics13071231

  View details for PubMedID 37046449

  View details for PubMedCentralID PMC10093025

• Emerging PET Tracers in Cardiac Molecular Imaging. Cardiology and therapy Singh, S. B., Ng, S. J., Lau, H. C., Khanal, K., Bhattarai, S., Paudyal, P., Shrestha, B. B., Naseer, R., Sandhu, S., Gokhale, S., Raynor, W. Y. 2023; 12 (1): 85-99

  Abstract

  18F-fluorodeoxyglucose (FDG) and 18F-sodium fluoride (NaF) represent emerging PET tracers used to assess atherosclerosis-related inflammation and molecular calcification, respectively. By localizing to sites with high glucose utilization, FDG has been used to assess myocardial viability for decades, and its role in evaluating cardiac sarcoidosis has come to represent a major application. In addition to determining late-stage changes such as loss of perfusion or viability, by targeting mechanisms present in atherosclerosis, PET-based techniques have the ability to characterize atherogenesis in the early stages to guide intervention. Although it was once thought that FDG would be a reliable indicator of ongoing plaque formation, micro-calcification as portrayed by NaF-PET/CT appears to be a superior method of monitoring disease progression. PET imaging with NaF has the additional advantage of being able to determine abnormal uptake due to coronary artery disease, which is obscured by physiologic myocardial activity on FDG-PET/CT. In this review, we discuss the evolving roles of FDG, NaF, and other PET tracers in cardiac molecular imaging.

  View details for DOI 10.1007/s40119-022-00295-1

  View details for PubMedID 36593382

  View details for PubMedCentralID PMC9986170

• Dual time-point imaging of lymphoma adenopathy using total-body FDG PET/CT Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2023 Shrestha, B., Singh, S., Motamedi, N., Werner, T., Nardo, L., Abdelhafez, Y., Alavi, A. 2023: P1444-P1444
• Chimeric antigen receptor T-cell treatment for non-Hodgkin lymphoma: A comprehensive bone marrow evaluation with FDG PET/CT Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2023 Shrestha, B., Singh, S., Ismoilov, M., Niazi, S., Ahmed, M., Motamedi, N., Werner, T., Revheim, M., Høilund-Carlsen, P., Alavi, A., Raynor, W. 2023: P1342-P1342
• Effects of chimeric antigen receptor T-cell therapy on pulmonary and hepatic FDG uptake in patients with non-Hodgkin lymphoma Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2023 Shrestha, B., Singh, S., Raynor, W., Ahmed, M., Valluru, S., Singh, R., Glennan, P., Shehu, V., Werner, T., Revheim, M., Høilund-Carlsen, P., Alavi, A. 2023: P1076-P1076
• The evolving role of [18F] DCFPyL (Pylarify) PET/CT in the management of Prostate Cancer Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2023 Jasaraj, R., Khanal, K., Bhusal, S., Shrestha, B., Singh, S. 2023: P1443-P1443
• Role of 18F-FDG PET/CT to evaluate the effects of chimeric antigen receptor T-cell therapy on lymph node involvement in patients with non-Hodgkin lymphoma Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2023 Shrestha, B., Singh, S., Raynor, W., Niazi, S., Ahmed, M., Ismoilov, M., Motamedi, N., Werner, T., Revheim, M., Høilund-Carlsen, P., Alavi, A. 2023: P1159-P1159
• A Review of 177Lutetium-PSMA and 225Actinium-PSMA as Emerging Theranostic Agents in Prostate Cancer. Cureus Alam, M. R., Singh, S. B., Thapaliya, S., Shrestha, S., Deo, S., Khanal, K. 2022; 14 (9): e29369

  Abstract

  The development of prostate-specific membrane antigen (PSMA) ligands labeled with radionuclides is a ground-breaking achievement in the management of prostate cancer. With the increasing use of 68Gallium-PSMA and 18F-DCFPyL (Pylarify) and their approval by the Food and Drug Administration (FDA), other PSMA agents and their unique characteristics are also being studied. Two other PSMA agents, namely 177Lutetium-PSMA (177Lu-PSMA) and 225Actinium-PSMA (225Ac-PSMA), are currently drawing the researcher's attention mainly due to their theranostic importance. Studies focusing on the essential characteristics of these two emerging radiotracers are relatively lacking. Hence, this review article, beginning with a brief introduction, intends to provide insights on the mechanism, efficacy, adverse effects, usefulness, including theranostic implications, and limitations of these two emerging PSMA agents. The 177Lu-PSMA is commercially accessible, is well tolerated, and has been found to lower prostate-specific antigen (PSA) levels while improving patients' quality of life. It also reduces pain and the requirement for analgesics and is safe for advanced diseases. However, despite its potential advantages, around one-third of patients do not respond satisfactorily to this costly treatment; it is still challenging to personalize this therapy and predict its outcome. Similarly, 225Ac is compatible with antibody-based targeting vectors, releasing four extremely hazardous high-energy emissions with a longer half-life of 10 days. It has made 225Ac-PSMA therapy useful for tumors resistant to standard treatments, with a better response than 177Lu-PSMA. Dosimetry studies show a good biochemical response without toxicity in patients with advanced metastatic castration-resistant prostate cancer (mCRPC). However, it can potentially cause significant damage to healthy tissues if not retained at the tumor site. Encapsulating radionuclides in a nano-carrier, hastening the absorption by tumor cells, and local delivery might all help reduce the harmful consequences. Both have advantages and disadvantages. The choice of PSMA agents may rely on desired qualities, cost, and convenience, among other factors. Further research is warranted in order to better understand their ideal use in clinical settings.

  View details for DOI 10.7759/cureus.29369

  View details for PubMedID 36284803

  View details for PubMedCentralID PMC9584169

• The effects of limb laterality and age on the inflammation and bone turnover of the acromioclavicular shoulder joint: 18 F-fluorodeoxyglucose and 18 F-sodium-fluoride-PET/computed tomography study. Nuclear medicine communications Park, P. S., McDonald, E., Singh, S. B., Raynor, W. Y., Werner, T. J., Høilund-Carlsen, P. F., Alavi, A. 2022; 43 (8): 922-927

  Abstract

  The acromioclavicular (AC) joint is a common site of injury and degenerative changes such as osteoarthritis (OA) of the shoulder. Physical manifestations of OA are preceded by molecular changes, detection of which may enhance early prophylaxis and monitoring of disease progression. In this study, we investigate the use of 18 F-FDG and 18 F-NaF-PET/CT to assess the effects of limb laterality and age on the inflammation and bone turnover of the AC shoulder joint.We analyzed FDG and NaF-PET/CT scans of 41 females (mean age of 43.9 ± 14.2 years) and 45 males (mean age of 44.5 ± 13.8 years) using a semiquantitative technique based on predefined ROI.There was a greater NaF uptake in the right side of the AC joint compared with the left in both females (left: 2.22 ± 1.00; right: 3.08 ± 1.18; P < 0.0001) and males (left: 2.57 ± 1.49; right: 2.99 ± 1.40; P = 0.003). No consistent correlation between age and NaF or FDG uptakes were found in both females and males. There was also a positive correlation between FDG and NaF uptakes in both left ( P = 0.01; r = 0.37) and right ( P = 0.0006; r = 0.53) AC joints of male subjects.Our study is the first to reveal the varying effect of right-left limb laterality and aging on FDG and NaF uptake at the AC joint. Future studies correlating the history of shoulder trauma, pain, and degenerative change with FDG and NaF-PET/CT findings will be critical in the adoption of molecular imaging in the clinical setting.

  View details for DOI 10.1097/MNM.0000000000001588

  View details for PubMedID 35634806

• Examining the role of FDG-PET/CT in early diagnosis and assessment of venous thromboembolism (VTE) Singh, S., Griffin, M., Revheim, M., Saboury, B., Werner, T., Alavi, A., Hess, S. SOC NUCLEAR MEDICINE INC. 2022

  View details for Web of Science ID 000893739700045

• Comparison of Global cardiac atherosclerosis burden with Alavi-Carlsen Calcification score (ACCS) relative to coronary artery calcification score (CACS) Khanal, K., Singh, S., Revheim, M., Saboury, B., Werner, T., Alavi, A. SOC NUCLEAR MEDICINE INC. 2022

  View details for Web of Science ID 000893739700046

• Is Imaging of Bacteria with PET a realistic goal? Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2022 Annual Meeting Singh, S., Raynor, W., Revheim, M., Saboury, B., Werner, T., Alavi, A., Hess, S. 2022: 2677-2677
• The evolving role of FAPI-PET in assessing patients with various malignancies and its potential superiority over FDG-PET in this setting Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2022 Annual Meeting Singh, S., Khurana, N. K., Saboury, B., Werner, T., Alavi, A., Revheim, M. 2022: 2711-2711
• Role of Natalizumab in Relapsing-Remitting Multiple Sclerosis: A review. Journal of Brain and Spine Foundation Nepal Paudel, A. K., Bastakoti, S., Dulal, N. R., Piya, G., Singh, S. B. 2021; 2 (1): 2-12
• Empowering Nepalese Villagers with Health Literacy through Maintenance of Personal Health Records in a Health Database Sonoda journal Sugino, M., Naito, T., Kanbara, M., Sawabe, T., Mizohata, S., Sawabe, M., Lama, N., Tamang, M., Jha, R., Shrestha, B., Dahal, M., Acharya, B., Shah, A., Thapa, B., Shrestha, S., Bhattarai, P., Singh, S., Khadka, A., Pandey, S., Maharjan, S., Mandal, S. 2020; 1: 45-54
• Addiction Psychiatry Training Experience, Belief about Addiction and Brief Screening for Substance Use among Medical Interns: A Cross-Sectional Survey Journal of Psychiatrists Association of Nepal Pokhrel, P. 2019; 8 (1): 45–49

  View details for DOI 10.3126/jpan.v8i1.26336