Johannes Hugo Decker

All Publications

• NeuroMix with MR Angiography: A Fast MR Protocol to Reduce Head and Neck CT Angiography for Patients with Acute Neurological Presentations. AJNR. American journal of neuroradiology Decker, J. H., Mazal, A. T., Bui, A., Sprenger, T., Skare, S., Fischbein, N., Zaharchuk, G. 2024

  Abstract

  BACKGROUND AND PURPOSE: Overuse of computed tomography (CT)-based cerebrovascular imaging in the emergency department (ED) and inpatient settings, notably CT angiography of the head and neck (CTAHN) for minor and non-focal neurological presentations, stresses imaging services and exposes patients to radiation and contrast. Furthermore, such CT-based imaging is often insufficient for definitive diagnosis, necessitating additional MR imaging. Recent advances in fast MRI may allow for timely assessment and reduced need for CTAHN in select populations.MATERIALS AND METHODS: We identified inpatients or ED patients who underwent CTAHN (including non-contrast and post-contrast CTH, with or without CT perfusion [CTP] imaging) followed within 24 hours by a 3T MRI study that included NeuroMix (an unenhanced 2.5 min multi-contrast sequence) and intracranial time-of-flight MR angiography (MRA; a 5 min sequence) during a 9-month period (April to December 2022). Cases were classified by 4 radiologists in consensus as to whether NeuroMix and NeuroMix+MRA detected equivalent findings, detected unique findings, or missed findings relative to CTAHN.RESULTS: 174 cases (mean age 67±16 yrs; 56% female) met the inclusion criteria. NeuroMix alone and NeuroMix+MRA protocols were determined to be equivalent or better compared to CTAHN in 71% and 95% of patients, respectively. NeuroMix always provided equivalent or better assessment of the brain parenchyma, with unique findings on NeuroMix and NeuroMix+MRA in 35% and 36% of cases, respectively, most commonly acute infarction or multiple microhemorrhages. In 8/174 cases (5%), CTAHN identified vascular abnormalities not seen on the NeuroMix+MRA protocol due to CTAHN's wider coverage of the cervical arteries.CONCLUSIONS: A fast MR imaging protocol consisting of NeuroMix+MRA provided equivalent or better information compared to CTAHN in 95% of cases in our population of patients with an acute neurological presentation. The findings provide a deeper understanding of the benefits and challenges of a fast unenhanced MR-first approach with NeuroMix+MRA, which could be used to design prospective trials in select patient groups, with the potential to reduce radiation dose, mitigate adverse contrast-related patient and environmental effects, and lessen the burden on radiologists and healthcare systems.ABBREVIATIONS: CTAHN = CTA Head and Neck including non-contrast and delayed post-contrast CT Head with or without CT perfusion, NeuroMix = unenhanced multi-contrast MR brain sequence.

  View details for DOI 10.3174/ajnr.A8386

  View details for PubMedID 38906674

• Automated Identification and Measurement Extraction of Pancreatic Cystic Lesions from Free-Text Radiology Reports Using Natural Language Processing. Radiology. Artificial intelligence Yamashita, R., Bird, K., Cheung, P. Y., Decker, J. H., Flory, M. N., Goff, D., Morimoto, L. N., Shon, A., Wentland, A. L., Rubin, D. L., Desser, T. S. 2022; 4 (2): e210092

  Abstract

  Purpose: To automatically identify a cohort of patients with pancreatic cystic lesions (PCLs) and extract PCL measurements from historical CT and MRI reports using natural language processing (NLP) and a question answering system.Materials and Methods: Institutional review board approval was obtained for this retrospective Health Insurance Portability and Accountability Act-compliant study, and the requirement to obtain informed consent was waived. A cohort of free-text CT and MRI reports generated between January 1991 and July 2019 that covered the pancreatic region were identified. A PCL identification model was developed by modifying a rule-based information extraction model; measurement extraction was performed using a state-of-the-art question answering system. The system's performance was evaluated against radiologists' annotations.Results: For this study, 430426 free-text radiology reports from 199783 unique patients were identified. The NLP model for identifying PCL was applied to 1000 test samples. The interobserver agreement between the model and two radiologists was almost perfect (Fleiss kappa = 0.951), and the false-positive rate and true-positive rate were 3.0% and 98.2%, respectively, against consensus of radiologists' annotations as ground truths. The overall accuracy and Lin concordance correlation coefficient for measurement extraction were 0.958 and 0.874, respectively, against radiologists' annotations as ground truths.Conclusion: An NLP-based system was developed that identifies patients with PCLs and extracts measurements from a large single-institution archive of free-text radiology reports. This approach may prove valuable to study the natural history and potential risks of PCLs and can be applied to many other use cases.Keywords: Informatics, Abdomen/GI, Pancreas, Cysts, Computer Applications-General (Informatics), Named Entity Recognition Supplemental material is available for this article. © RSNA, 2022See also commentary by Horii in this issue.

  View details for DOI 10.1148/ryai.210092

  View details for PubMedID 35391762

• Acquired Esophagobronchial Fistula in a Patient with Hodgkin's Lymphoma ISRAEL MEDICAL ASSOCIATION JOURNAL Decker, J., Desser, T., Gayer, G. 2019; 21 (9): 634–35

  View details for Web of Science ID 000489674500017

• From Creatures of Habit to Goal-Directed Learners: Tracking the Developmental Emergence of Model-Based Reinforcement Learning. Psychological science Decker, J. H., Otto, A. R., Daw, N. D., Hartley, C. A. 2016; 27 (6): 848-58

  Abstract

  Theoretical models distinguish two decision-making strategies that have been formalized in reinforcement-learning theory. A model-based strategy leverages a cognitive model of potential actions and their consequences to make goal-directed choices, whereas a model-free strategy evaluates actions based solely on their reward history. Research in adults has begun to elucidate the psychological mechanisms and neural substrates underlying these learning processes and factors that influence their relative recruitment. However, the developmental trajectory of these evaluative strategies has not been well characterized. In this study, children, adolescents, and adults performed a sequential reinforcement-learning task that enabled estimation of model-based and model-free contributions to choice. Whereas a model-free strategy was apparent in choice behavior across all age groups, a model-based strategy was absent in children, became evident in adolescents, and strengthened in adults. These results suggest that recruitment of model-based valuation systems represents a critical cognitive component underlying the gradual maturation of goal-directed behavior.

  View details for DOI 10.1177/0956797616639301

  View details for PubMedID 27084852

  View details for PubMedCentralID PMC4899156

• On Weight and Waiting: Delay Discounting in Anorexia Nervosa Pretreatment and Posttreatment. Biological psychiatry Decker, J. H., Figner, B., Steinglass, J. E. 2015; 78 (9): 606-14

  Abstract

  Individuals with anorexia nervosa (AN) override the drive to eat, forgoing immediate rewards in favor of longer-term goals. We examined delay discounting and its neural correlates in AN before and after treatment to test a potential mechanism of illness persistence.Inpatients with AN (n = 59) and healthy control subjects (HC, n = 39) performed a delay discounting task at two time points. A subset (n = 30 AN, n = 22 HC) participated in functional magnetic resonance imaging scanning during the task. The task consisted of a range of monetary choices with variable delay times, yielding individual discount rates-the rate by which money loses value over time.Before treatment, the AN group showed a preference for delayed over earlier rewards (i.e., less steep discount rates) compared with HC; after weight restoration, AN did not differ from HC. Underweight AN showed slower response times for earlier versus delayed choices; this reversed with treatment. Underweight AN showed abnormal neural activity in striatum and dorsal anterior cingulate; normalization of behavior was associated with increased activation in reward regions (striatum and dorsal anterior cingulate) and decision-making regions (dorsolateral prefrontal cortex and parietal cortex).The undernourished state of AN may amplify the tendency to forgo immediate rewards in favor of longer-term goals. The results suggest that behavior that looks phenotypically like excessive self-control does not correspond with enhanced prefrontal recruitment. Rather, the results point to alterations in cingulostriatal circuitry that offer new insights on the potential role of abnormalities in decision-making neural systems in the perpetuation of AN.

  View details for DOI 10.1016/j.biopsych.2014.12.016

  View details for PubMedID 25641636

  View details for PubMedCentralID PMC4478277

• Experiential reward learning outweighs instruction prior to adulthood. Cognitive, affective & behavioral neuroscience Decker, J. H., Lourenco, F. S., Doll, B. B., Hartley, C. A. 2015; 15 (2): 310-20

  Abstract

  Throughout our lives, we face the important task of distinguishing rewarding actions from those that are best avoided. Importantly, there are multiple means by which we acquire this information. Through trial and error, we use experiential feedback to evaluate our actions. We also learn which actions are advantageous through explicit instruction from others. Here, we examined whether the influence of these two forms of learning on choice changes across development by placing instruction and experience in competition in a probabilistic-learning task. Whereas inaccurate instruction markedly biased adults' estimations of a stimulus's value, children and adolescents were better able to objectively estimate stimulus values through experience. Instructional control of learning is thought to recruit prefrontal-striatal brain circuitry, which continues to mature into adulthood. Our behavioral data suggest that this protracted neurocognitive maturation may cause the motivated actions of children and adolescents to be less influenced by explicit instruction than are those of adults. This absence of a confirmation bias in children and adolescents represents a paradoxical developmental advantage of youth over adults in the unbiased evaluation of actions through positive and negative experience.

  View details for DOI 10.3758/s13415-014-0332-5

  View details for PubMedID 25582607

  View details for PubMedCentralID PMC4437867

• Derivation of Injury-Responsive Dendritic Cells for Acute Brain Targeting and Therapeutic Protein Delivery in the Stroke-Injured Rat PLOS ONE Manley, N. C., Caso, J. R., Works, M. G., Cutler, A. B., Zemlyak, I., Sun, G., Munhoz, C. D., Chang, S., Sorrells, S. F., Ermini, F. V., Decker, J. H., Bertrand, A. A., Dinkel, K. M., Steinberg, G. K., Sapolsky, R. M. 2013; 8 (4)

  Abstract

  Research with experimental stroke models has identified a wide range of therapeutic proteins that can prevent the brain damage caused by this form of acute neurological injury. Despite this, we do not yet have safe and effective ways to deliver therapeutic proteins to the injured brain, and this remains a major obstacle for clinical translation. Current targeted strategies typically involve invasive neurosurgery, whereas systemic approaches produce the undesirable outcome of non-specific protein delivery to the entire brain, rather than solely to the injury site. As a potential way to address this, we developed a protein delivery system modeled after the endogenous immune cell response to brain injury. Using ex-vivo-engineered dendritic cells (DCs), we find that these cells can transiently home to brain injury in a rat model of stroke with both temporal and spatial selectivity. We present a standardized method to derive injury-responsive DCs from bone marrow and show that injury targeting is dependent on culture conditions that maintain an immature DC phenotype. Further, we find evidence that when loaded with therapeutic cargo, cultured DCs can suppress initial neuron death caused by an ischemic injury. These results demonstrate a non-invasive method to target ischemic brain injury and may ultimately provide a way to selectively deliver therapeutic compounds to the injured brain.

  View details for DOI 10.1371/journal.pone.0061789

  View details for Web of Science ID 000317893400111

  View details for PubMedID 23613937

  View details for PubMedCentralID PMC3627911

• Diffraction study of protein crystals grown in cryoloops and micromounts JOURNAL OF APPLIED CRYSTALLOGRAPHY Berger, M. A., Decker, J. H., Mathews, I. I. 2010; 43: 1513-1518

  Abstract

  Protein crystals are usually grown in hanging or sitting drops and generally get transferred to a loop or micromount for cryocooling and data collection. This paper describes a method for growing crystals on cryoloops for easier manipulation of the crystals for data collection. This study also investigates the steps for the automation of this process and describes the design of a new tray for the method. The diffraction patterns and the structures of three proteins grown by both the new method and the conventional hanging-drop method are compared. The new setup is optimized for the automation of the crystal mounting process. Researchers could prepare nanolitre drops under ordinary laboratory conditions by growing the crystals directly in loops or micromounts. As has been pointed out before, higher levels of supersaturation can be obtained in very small volumes, and the new method may help in the exploration of additional crystallization conditions.

  View details for DOI 10.1107/S0021889810040409

  View details for Web of Science ID 000284550900029

  View details for PubMedID 22477781