NNC » People

Core Leaders

Dr. Detre is Principal Investigator of the overall Center Core and Director of the Administrative and Acquisition Cores. He has been actively engaged in neuroimaging research at the University of Pennsylvania since 1988 and continuously funded since 1993, including K08, K02, K24, R01, R25, and T32 grants from NINDS.  He has collaborated widely with other investigators in this field, both in technical development and in applications.  He is widely recognized as an expert in functional neuroimaging, perfusion imaging, and clinical applications of neuroimaging.  These credentials have allowed Dr. Detre to provide successful interdisciplinary leadership in neuroimaging initiatives. Dr. Detre began working in in vivo neuroimaging as a medical student and over the past 20 years, his research has focused on physiological imaging methods and applications, including MRI, PET, and optical imaging in both preclinical models and humans.  He is an inventor of arterial spin labeled (ASL) perfusion MRI and pioneered many of its applications to neurological disorders.  He is also recognized as a leading expert in functional neuroimaging methods and applications.  Dr. Detre is Vice Chair for Research in the Department of Neurology, Director of the Center for Functional Neuroimaging in the Department of Radiology, and has been Principal Investigator of this P30 Center Core for the past 9 years.


Dr. Yushkevich is co-Director of the Informatics Core. He is a computer scientist with expertise across
different fields of image analysis and visualization, including advanced morphometry and segmentation
methods for structural, functional and diffusion MRI analysis. He has developed open-source software for both
interactive and distributed processing of neuroimaging data, including ITK-SNAP (, arguably
the most widely used interactive medical image segmentation tools. Dr. Yushkevich oversaw the
implementation, expansion, and maintenance of the computing cluster that currently serves much of the NNC
user community.

Dr. Davatzikos joins Dr. Yushkevich as co-Director of the Informatics Core for the next project period. Dr.
Davatzikos’ research program includes many areas related to medical image analysis and computing including
image segmentation and registration, multiparametric image analysis, as well as the use of machine learning
and pattern recognition in medical imaging. His group is affiliated with many clinical neuroscience studies
employing imaging as a biomarker of diseases such as Alzheimer's, schizophrenia, diabetes, and cancer. As
Director of the Center for Biomedical Image Computing and Analysis, Dr. Davatzikos also has expertise in
managing core computing support. His recent NIH S10 proposal to acquire a $2M high-performance
computing cluster for biomedical research receive a perfect score, and is anticipated to replace the current
NNC computing cluster during the course of the next project period.


Core Personnel

Dr. Aguirre is a behavioral neurologist and neuroscientist who has used neuroimaging techniques to study the cortical basis of vision since 1995. Much of his work advances the methodology of functional neuroimaging, and integrates across structure and function, healthy and patient populations, human and animal models, and electrophysiological and MRI techniques. He has been involved in the creation and dissemination of software for neuroimaging throughout his career. His breadth of methodological knowledge and computational implementation makes him well suited to direct this core. Also, Dr. Aguirre studies the cortical basis of visual cognition. His research makes use of both structural and functional MRI techniques, and within this field he has made substantial methodological contributions. He has particular expertise in the design and analysis of functional MRI time-series data and in the efficient design of neuroimaging studies. He has developed graph-theoretic approaches to experimental design, which provide for more rigorous and powerful experiments. He has co-taught a graduate course on neuroimaging methodology at Penn and has introduced students to "fMRI 101" at Penn for fifteen years.

Mark Elliott, PhD is a staff physicist focusing on structural MRI, fMRI, DTI, and multinuclear imaging.  He is operations manager for the 3 Tesla MRI system dedicated to neuroscience research as well as the 7 Tesla MRI system.  He is the primary contact for protocol implementation and is responsible for quality assurance testing on these instruments.  He also supervises the installation and maintenance of ancillary instrumentation for stimulus presentation and biobehavioral monitoring.

Roy Hamilton, MD, PhD is a cognitive neurologist and cognitive neuroscientist and manages the TMS lab in the Department of Neurology.

Desmond Oathes, PhD is a psychologist with expertise in transcranial magnetic stimulation (TMS) and
provides consultative expertise in TMS neuromodulation in association with and during MRI scanning.

Steven Pickup, PhD has been working in the field of magnetic resonance methods development and applications for approximately 30 years.  He has been Director of the small animal MRI facilities at the University of Pennsylvania since his arrival at the institution in 2000 and as Technical Director of the Small Animal Imaging Facility (SAIF) since it was founded in 2006.  The small animal MRI resources at Penn have recently been upgraded to state of the art levels as a result of two successful shared instrument grant applications authored by Dr. Pickup.

Karthik Prabhakaran, MS has extensive expertise in research MRI, scanner operation and safety, and in ancillary
biobehavioral response monitoring. He assists in the training of users in MRI operations and is responsible for
the maintenance of behavioral monitoring equipment for use in fMRI.

Ravinder Reddy, PhD is Director of the Center for Magnetic Resonance and Optical imaging and provides
consultative expertise in metabolic MRI including glutamate mapping, lactate mapping, and creatine mapping
using chemical exchange saturation transfer technologies developed in his laboratory.

Hengyi Rao, PhD is a cognitive neuroscientist who has been working with neuroimaging and electrophysiological methods for over a decade.  Much of his research applications of ASL MRI in sleep and cognition, and he provides support for the use of EEG/ERP instrumentation that can be used concurrently with fMRI acquisition.  He also supports modeling of ASL fMRI for the Data Acquisition Core.

Haochang Shou, PhD is a statistician with specific expertise in spatiotemporal statistics relevant to neuroimaging. She provides consultation on statistical analysis of multimodal neuroimaging data.

M. Dylan Tisdall, PhD is a recently-recruited computer scientist and MRI engineer with expertise in structural
MRI, motion compensation, as well as pulse sequence programming and signal processing on the Siemens
platform. He provides complementary expertise to Dr. Elliott by maintaining structural imaging capabilities,
motion compensation schemes, and required modifications to customized imaging sequences. He assists Dr.
Elliott in user training.

Felix Wehrli, PhD is a renowned MRI biophysicist who provides consultative expertise in dynamic MRI based
monitoring of cerebral oxygen metabolism using novel susceptibility-based technologies developed in his

Ronald Wolf, MD, PhD. is an academic radiologist whose research focuses on functional and physiological
neuroimaging. He assists NNC users with the assessment of incidental findings found in normal volunteers or
unexpected findings in patients with known lesions, with clinical interpretation of structural MRI studies.

Other Personnel

Mark Bergman has expertise in system administration for high-performance computing. Mr. Bergman devotes his full effort to system administration in the Center for Biomedical Imaging and Computing and Analytics. He will supervise the transition from the current NNC cluster to the new high-performance cluster.

Rupal Bhavsar is a part time research coordinator and is responsible for data acquisition for various fMRI protocols through coordination of research subjects.

Philip Cook, Ph.D. has expertise in computerized brain morphometry, diffusion tensor imaging, connectomics. He provides consultative expertise and maintains HCP and NODDI pipelines.

Jeffrey Duda, Ph.D. has expertise in ANTs/ANTsR-based advanced image analysis. He maintains these pipelines and provides consultative expertise in their use.

Guray Erus, Ph.D. has expertise image segmentation and registration, multiparametric image analysis, and the use of machine learning and pattern recognition in medical imaging. He provides consultative expertise in the use of CBICA pipelines for high-throughput image analysis.

Margaret Ryan, MLA has been the associate director for the administrative core since 2003. She has a deep institutional knowledge of Penn and research administration, a background in medical publishing and is a valuable source of knowledge regarding regulatory information and user training. She is an active member of SOCRA and is an original Penn certified Clinical Research Coordinator. Margaret has served as a member of CAMRIS committee (radiology safety committee) since 2004. She is responsible for the MRI scheduling calendar, all websites, development/outreach, supervisory functions and overall operational and administrative functions of the NNC.

Michael Stauffer is a system administrator and is responsible for the maintenance of our computing clusters, data storage, backup, and archiving, the web server, and for assisting new investigators wishing to access the computing cluster or to establish data processing facilities within their own laboratories.



Brian B. Avants, PhD was a Research Assistant Professor of Radiology. He specializes in deeply software engineered image quantification tools that are cross-platform, unit-tested and developed by distributed teams. He is the original author of Advanced Normalization Tools (ANTs), which sets the standard for accessibility and performance in image registration and optimal anatomical template construction across imaging modalities, species and organs. He has also developed numerous approaches for multi-modality registration, segmentation and multivariate image analysis, leads ITKv4 image registration refactoring, and is currently developing integrated high-dimensional brain mapping tools within the R statistical programming environment.

James Gee, PhD was Director of the Data Analysis Core in previous years. He is among the leadership as well as a longtime member of the Penn neuroimaging research community, earning his first R01 award from NINDS in 1995 while still a graduate student at Penn.  As one of the world’s foremost experts in computational anatomy, his multifaceted contributions to the field of medical image analysis are widely recognized. His seminal work on deformable image registration, its transformative application to the development of digital brain atlases and groundbreaking extensions to population templates and diffusion tensor imaging have established not only the state-of-the-art but the basis for major new research tracks that now dominate the field. Dr. Gee’s translation of his research accomplishments into highly acclaimed open-source software has further benefitted the field. In short, Dr. Gee is internationally recognized for his leadership in the analysis of brain imagery. With over 20 years of experience, he has contributed to virtually every area of statistical and morphometric image analysis methodology, and has promoted collaboration and open access to analysis software.

Joel Greenberg, PhD has 40 years of experience working in cerebral blood flow and metabolism, primarily in animal models.  For the past 20 years he has collaborated closely with the optics group in physics to translate novel optical technologies to applications in brain research.  He supports the use of optical monitoring in both humans and animal models as well as providing consultative support for animal modeling during MRI.

Jeremy Magland, PhD is an Assistant Professor of Radiology with a background in mathematics and computer science and six years of hands-on experience with pulse sequence design, medical image processing, and scientific software development. He developed a flexible software framework for incorporating real-time capabilities into functional MRI experiments, including tools for rapid data collection, image analyses, and custom visualization of fMRI results in real-time.

John Pluta, was a senior research assistant, has an undergraduate degree in engineering, and was working in the NNC for 6 years assisting users with stimulus development and the use of stimulus delivery and biobehavioral response monitoring equipment. For the data analysis core, John Pluta also assisted users with the Core’s software and training resources, including helping to run analysis pipelines and protocols as well as providing individualized training on these capabilities.

Harish Poptani, PhD has worked on using in vivo MRI and MRS techniques for brain and cancer for over 20 years, and provided support for these methods in humans and rodent models. Spectroscopic methods for human brain include a high-resolution whole brain 3D MRS imaging method at 3 Tesla and a single voxel 2D L-COSY at 7 Tesla. He developed methods for high-throughput MR microscopy of the mouse brain, high-resolution stem cell tracking in the mouse brain, and diffusion tensor imaging for isolated tissues. 

Ze Wang, PhD, a Research Assistant Professor of Biomedical Engineering, has extensive experience in signal processing using various advanced methods such as PCA, ICA, WT, and SVM.  He developed the ASLtbx software for ASL fMRI data analysis.