Ashish Raj, PhD
Professor
Radiology
School of Medicine

I have published more than 70 peer reviewed papers ranging from microwave engineering, superconductivity, image/signal processing, vision, graph theory and neuroscience, and two US patents. I have attracted several NIH grants, on graph algorithms for accelerated MRI, theoretical neuroscience and network modeling of dementia and Parkinson’s.

The defining characteristic of my work has been inter-disciplinarity: finding innovative ways to apply computation and algorithms to biomedical applications. My group was an early adopter of mathematical models of brain connectivity networks, a subject that marries computer science with neuroradiology. I have deep interest in the graph properties of brain networks, and how they are altered in neurological disorders like epilepsy, dementia, movement disorders, traumatic brain injury and stroke. A recent project on dementia modeling was selected by the NIH for the prestigious EUREKA award that supports highly innovative but risky research, and another by the BRAIN Initiative. My team has developed novel image reconstruction algorithms for fast MRI, motion correction for MR angiography, and new methods in tractography, Q-ball imaging, brain connectivity networks and computational neurology.

My research program is now perfectly poised to help bring the fields of neurology and radiology into the era of personalized, precision medicine, using mathematical modeling and data science.

• Cortical Synchrony and Information Flow during Transition from Wakefulness to Light Non-Rapid Eye Movement Sleep.
  The Journal of neuroscience : the official journal of the Society for Neuroscience 2023 Fan JM, Kudo K, Verma P, Ranasinghe KG, Morise H, Findlay AM, Vossel K, Kirsch HE, Raj A, Krystal AD, Nagarajan SS
• Impaired long-range excitatory time scale predicts abnormal neural oscillations and cognitive deficits in Alzheimer's disease.
  Research square 2023 Verma P, Ranasinghe K, Prasad J, Cai C, Xie X, Lerner H, Mizuiri D, Miller B, Rankin K, Vossel K, Cheung SW, Nagarajan S, Raj A
• Spatial cell-type enrichment predicts mouse brain connectivity.
  Cell reports 2023 Sun S, Torok J, Mezias C, Ma D, Raj A
• Dynamic functional connectivity MEG features of Alzheimer's disease.
  NeuroImage 2023 Jin H, Ranasinghe KG, Prabhu P, Dale C, Gao Y, Kudo K, Vossel K, Raj A, Nagarajan SS, Jiang F
• Bayesian inference of a spectral graph model for brain oscillations.
  NeuroImage 2023 Jin H, Verma P, Jiang F, Nagarajan SS, Raj A
• Bayesian Inference of a Spectral Graph Model for Brain Oscillations.
  bioRxiv : the preprint server for biology 2023 Jin H, Verma P, Jiang F, Nagarajan S, Raj A
• A joint subspace mapping between structural and functional brain connectomes.
  NeuroImage 2023 Ghosh S, Raj A, Nagarajan SS
• Stability and dynamics of a spectral graph model of brain oscillations.
  Network neuroscience (Cambridge, Mass.) 2023 Verma P, Nagarajan S, Raj A
• The effects of microglia on tauopathy progression can be quantified using Nexopathy in silico (Nexis) models.
  Scientific reports 2022 Anand C, Maia PD, Torok J, Mezias C, Raj A
• Editorial: Advances in brain functional and structural networks modeling via graph theory.
  Frontiers in neuroscience 2022 Abdelnour F, Kuceyeski A, Raj A, Iturria-Medina Y, Deslauriers-Gauthier S
• Structure-function models of temporal, spatial, and spectral characteristics of non-invasive whole brain functional imaging.
  Frontiers in neuroscience 2022 Raj A, Verma P, Nagarajan S
• Connectome-based biophysics models of Alzheimer's disease diagnosis and prognosis.
  Translational research : the journal of laboratory and clinical medicine 2022 Torok J, Anand C, Verma P, Raj A
• Altered excitatory and inhibitory neuronal subpopulation parameters are distinctly associated with tau and amyloid in Alzheimer's disease.
  eLife 2022 Ranasinghe KG, Verma P, Cai C, Xie X, Kudo K, Gao X, Lerner H, Mizuiri D, Strom A, Iaccarino L, La Joie R, Miller BL, Gorno-Tempini ML, Rankin KP, Jagust WJ, Vossel K, Rabinovici GD, Raj A, Nagarajan …
• High activity and high functional connectivity are mutually exclusive in resting state zebrafish and human brains.
  BMC biology 2022 Zarei M, Xie D, Jiang F, Bagirov A, Huang B, Raj A, Nagarajan S, Guo S
• Matrix Inversion and Subset Selection (MISS): A pipeline for mapping of diverse cell types across the murine brain.
  Proceedings of the National Academy of Sciences of the United States of America 2022 Mezias C, Torok J, Maia PD, Markley E, Raj A
• Time-varying dynamic network model for dynamic resting state functional connectivity in fMRI and MEG imaging.
  NeuroImage 2022 Jiang F, Jin H, Gao Y, Xie X, Cummings J, Raj A, Nagarajan S
• Predicting Functional Connectivity From Observed and Latent Structural Connectivity via Eigenvalue Mapping.
  Frontiers in neuroscience 2022 Cummings JA, Sipes B, Mathalon DH, Raj A
• Modeling seeding and neuroanatomic spread of pathology in amyotrophic lateral sclerosis.
  NeuroImage 2022 Pandya S, Maia PD, Freeze B, Menke RAL, Talbot K, Turner MR, Raj A
• Spectral graph theory of brain oscillations--Revisited and improved.
  NeuroImage 2022 Verma P, Nagarajan S, Raj A
• Emergence of directional bias in tau deposition from axonal transport dynamics.
  PLoS computational biology 2021 Torok J, Maia PD, Verma P, Mezias C, Raj A
• Combined Model of Aggregation and Network Diffusion Recapitulates Alzheimer's Regional Tau-Positron Emission Tomography.
  Brain connectivity 2021 Raj A, Tora V, Gao X, Cho H, Choi JY, Ryu YH, Lyoo CH, Franchi B
• Network-constrained technique to characterize pathology progression rate in Alzheimer's disease.
  Brain communications 2021 Powell F, Tosun D, Raj A, Alzheimer’s Disease Neuroimaging Initiative
• Graph Models of Pathology Spread in Alzheimer's Disease: An Alternative to Conventional Graph Theoretic Analysis.
  Brain connectivity 2021 Raj A
• Emergence of canonical functional networks from the structural connectome.
  NeuroImage 2021 Xie X, Cai C, Damasceno PF, Nagarajan SS, Raj A
• Population-based input function for TSPO quantification and kinetic modeling with [11C]-DPA-713.
  EJNMMI physics 2021 Akerele MI, Zein SA, Pandya S, Nikolopoulou A, Gauthier SA, Raj A, Henchcliffe C, Mozley PD, Karakatsanis NA, Gupta A, Babich J, Nehmeh SA
• Network model of pathology spread recapitulates neurodegeneration and selective vulnerability in Huntington's Disease.
  NeuroImage 2021 Raj A, Powell F
• Algebraic relationship between the structural network's Laplacian and functional network's adjacency matrix is preserved in temporal lobe epilepsy subjects.
  NeuroImage 2020 Abdelnour F, Dayan M, Devinsky O, Thesen T, Raj A
• Molecular Imaging of Striatal Dopaminergic Neuronal Loss and the Neurovascular Unit in Parkinson Disease.
  Frontiers in neuroscience 2020 Ivanidze J, Skafida M, Pandya S, Patel D, Osborne JR, Raj A, Gupta A, Henchcliffe C, Dyke JP
• A dictionary-based graph-cut algorithm for MRI reconstruction.
  NMR in biomedicine 2020 Xu J, Pannetier N, Raj A
• Origins of atrophy in Parkinson linked to early onset and local transcription patterns.
  Brain communications 2020 Maia PD, Pandya S, Freeze B, Torok J, Gupta A, Zeighami Y, Raj A
• Network mediation of pathology pattern in sporadic Creutzfeldt-Jakob disease.
  Brain communications 2020 Freeze B, Maia P, Pandya S, Raj A
• Spectral graph theory of brain oscillations.
  Human brain mapping 2020 Raj A, Cai C, Xie X, Palacios E, Owen J, Mukherjee P, Nagarajan S
• Stereotaxic Diffusion Tensor Imaging White Matter Atlas for the in vivo Domestic Feline Brain.
  Frontiers in neuroanatomy 2020 Johnson PJ, Pascalau R, Luh WM, Raj A, Cerda-Gonzalez S, Barry EF
• Dynamical Role of Pivotal Brain Regions in Parkinson Symptomatology Uncovered with Deep Learning.
  Brain sciences 2020 Nguyen AA, Maia PD, Gao X, F Damasceno P, Raj A
• Neural connectivity predicts spreading of alpha-synuclein pathology in fibril-injected mouse models: Involvement of retrograde and anterograde axonal propagation.
  Neurobiology of disease 2019 Mezias C, Rey N, Brundin P, Raj A
• Regional transcriptional architecture of Parkinson's disease pathogenesis and network spread.
  Brain : a journal of neurology 2019 Freeze B, Pandya S, Zeighami Y, Raj A
• Longitudinal increases in structural connectome segregation and functional connectome integration are associated with better recovery after mild TBI.
  Human brain mapping 2019 Kuceyeski AF, Jamison KW, Owen JP, Raj A, Mukherjee P
• Slow-gamma frequencies are optimally guarded against effects of neurodegenerative diseases and traumatic brain injuries.
  Journal of computational neuroscience 2019 Maia PD, Raj A, Kutz JN
• Editorial: Network Spread Models of Neurodegenerative Diseases.
  Frontiers in neurology 2019 Raj A, Iturria-Medina Y
• Normal diffusivity of the domestic feline brain.
  The Journal of comparative neurology 2018 Barry EF, Cerda-Gonzalez S, Luh WM, Daws RE, Raj A, Johnson PJ
• Models of Network Spread and Network Degeneration in Brain Disorders.
  Biological psychiatry. Cognitive neuroscience and neuroimaging 2018 Raj A, Powell F
• A method for inferring regional origins of neurodegeneration.
  Brain : a journal of neurology 2018 Torok J, Maia PD, Powell F, Pandya S, Raj A
• Functional brain connectivity is predictable from anatomic network's Laplacian eigen-structure.
  NeuroImage 2018 Abdelnour F, Dayan M, Devinsky O, Thesen T, Raj A
• Regional expression of genes mediating trans-synaptic alpha-synuclein transfer predicts regional atrophy in Parkinson disease.
  NeuroImage. Clinical 2018 Freeze B, Acosta D, Pandya S, Zhao Y, Raj A
• Regional vulnerability in Alzheimer's disease: The role of cell-autonomous and transneuronal processes.
  Alzheimer's & dementia : the journal of the Alzheimer's Association 2018 Acosta D, Powell F, Zhao Y, Raj A
• Preserved Structural Network Organization Mediates Pathology Spread in Alzheimer's Disease Spectrum Despite Loss of White Matter Tract Integrity.
  Journal of Alzheimer's disease : JAD 2018 Powell F, Tosun D, Sadeghi R, Weiner M, Raj A, Alzheimer’s Disease Neuroimaging Initiative
• Predictive Model of Spread of Progressive Supranuclear Palsy Using Directional Network Diffusion.
  Frontiers in neurology 2017 Pandya S, Mezias C, Raj A
• Analysis of Amyloid-β Pathology Spread in Mouse Models Suggests Spread Is Driven by Spatial Proximity, Not Connectivity.
  Frontiers in neurology 2017 Mezias C, Raj A
• Age-Related Changes in Topological Degradation of White Matter Networks and Gene Expression in Chronic Schizophrenia.
  Brain connectivity 2017 Powell F, LoCastro E, Acosta D, Ahmed M, O'Donoghue S, Forde N, Cannon D, Scanlon C, Rao T, McDonald C, Raj A
• Mature Hippocampal Neurons Require LIS1 for Synaptic Integrity: Implications for Cognition.
  Biological psychiatry 2017 Sudarov A, Zhang XJ, Braunstein L, LoCastro E, Singh S, Taniguchi Y, Raj A, Shi SH, Moore H, Ross ME
• Connectivity, not region-intrinsic properties, predicts regional vulnerability to progressive tau pathology in mouse models of disease.
  Acta neuropathologica communications 2017 Mezias C, LoCastro E, Xia C, Raj A
• Brain network eigenmodes provide a robust and compact representation of the structural connectome in health and disease.
  PLoS computational biology 2017 Wang MB, Owen JP, Mukherjee P, Raj A
• MRI Analysis of White Matter Myelin Water Content in Multiple Sclerosis: A Novel Approach Applied to Finding Correlates of Cortical Thinning.
  Frontiers in neuroscience 2017 Dayan M, Hurtado Rúa SM, Monohan E, Fujimoto K, Pandya S, LoCastro EM, Vartanian T, Nguyen TD, Raj A, Gauthier SA
• The Brain's Structural Connectome Mediates the Relationship between Regional Neuroimaging Biomarkers in Alzheimer's Disease.
  Journal of Alzheimer's disease : JAD 2017 Pandya S, Kuceyeski A, Raj A, Alzheimer’s Disease Neuroimaging Initiative
• Network Analysis on Predicting Mean Diffusivity Change at Group Level in Temporal Lobe Epilepsy.
  Brain connectivity 2016 Abdelnour F, Raj A, Devinsky O, Thesen T
• Diffuse reduction of cerebral grey matter volumes in Erdheim-Chester disease.
  Orphanet journal of rare diseases 2016 Diamond EL, Hatzoglou V, Patel S, Abdel-Wahab O, Rampal R, Hyman DM, Holodny AI, Raj A
• Structural connectome disruption at baseline predicts 6-months post-stroke outcome.
  Human brain mapping 2016 Kuceyeski A, Navi BB, Kamel H, Raj A, Relkin N, Toglia J, Iadecola C, O'Dell M
• Profilometry: A new statistical framework for the characterization of white matter pathways, with application to multiple sclerosis.
  Human brain mapping 2015 Dayan M, Monohan E, Pandya S, Kuceyeski A, Nguyen TD, Raj A, Gauthier SA
• Relating Cortical Atrophy in Temporal Lobe Epilepsy with Graph Diffusion-Based Network Models.
  PLoS computational biology 2015 Abdelnour F, Mueller S, Raj A
• Measuring longitudinal myelin water fraction in new multiple sclerosis lesions.
  NeuroImage. Clinical 2015 Vargas WS, Monohan E, Pandya S, Raj A, Vartanian T, Nguyen TD, Hurtado Rúa SM, Gauthier SA
• Feasibility and reproducibility of whole brain myelin water mapping in 4 minutes using fast acquisition with spiral trajectory and adiabatic T2prep (FAST-T2) at 3T.
  Magnetic resonance in medicine 2015 Nguyen TD, Deh K, Monohan E, Pandya S, Spincemaille P, Raj A, Wang Y, Gauthier SA
• Exploring the brain's structural connectome: A quantitative stroke lesion-dysfunction mapping study.
  Human brain mapping 2015 Kuceyeski A, Navi BB, Kamel H, Relkin N, Villanueva M, Raj A, Toglia J, O'Dell M, Iadecola C
• Network Diffusion Model of Progression Predicts Longitudinal Patterns of Atrophy and Metabolism in Alzheimer's Disease.
  Cell reports 2015 Raj A, LoCastro E, Kuceyeski A, Tosun D, Relkin N, Weiner M, Alzheimer’s Disease Neuroimaging Initiative (ADNI)
• Simultaneous phase unwrapping and removal of chemical shift (SPURS) using graph cuts: application in quantitative susceptibility mapping.
  IEEE transactions on medical imaging 2014 Dong J, Liu T, Chen F, Zhou D, Dimov A, Raj A, Cheng Q, Spincemaille P, Wang Y
• Widespread white matter degeneration preceding the onset of dementia.
  Alzheimer's & dementia : the journal of the Alzheimer's Association 2014 Maier-Hein KH, Westin CF, Shenton ME, Weiner MW, Raj A, Thomann P, Kikinis R, Stieltjes B, Pasternak O
• Multi-compartment T2 relaxometry using a spatially constrained multi-Gaussian model.
  PloS one 2014 Raj A, Pandya S, Shen X, LoCastro E, Nguyen TD, Gauthier SA
• Spatial patterns of genome-wide expression profiles reflect anatomic and fiber connectivity architecture of healthy human brain.
  Human brain mapping 2014 Goel P, Kuceyeski A, LoCastro E, Raj A
• Predicting future brain tissue loss from white matter connectivity disruption in ischemic stroke.
  Stroke 2014 Kuceyeski A, Kamel H, Navi BB, Raj A, Iadecola C
• Network diffusion accurately models the relationship between structural and functional brain connectivity networks.
  NeuroImage 2013 Abdelnour F, Voss HU, Raj A
• Discriminative random field segmentation of lung nodules in CT studies.
  Computational and mathematical methods in medicine 2013 Liu B, Raj A
• Robust myelin quantitative imaging from multi-echo T2 MRI using edge preserving spatial priors.
  Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention 2013 Shen X, Nguyen TD, Gauthier SA, Raj A
• The Network Modification (NeMo) Tool: elucidating the effect of white matter integrity changes on cortical and subcortical structural connectivity.
  Brain connectivity 2013 Kuceyeski A, Maruta J, Relkin N, Raj A
• Loss in connectivity among regions of the brain reward system in alcohol dependence.
  Human brain mapping 2012 Kuceyeski A, Meyerhoff DJ, Durazzo TC, Raj A
• Statistics of weighted brain networks reveal hierarchical organization and Gaussian degree distribution.
  PloS one 2012 Ivkovic M, Kuceyeski A, Raj A
• A network diffusion model of disease progression in dementia.
  Neuron 2012 Raj A, Kuceyeski A, Weiner M
• Linking white matter integrity loss to associated cortical regions using structural connectivity information in Alzheimer's disease and fronto-temporal dementia: the Loss in Connectivity (LoCo) score.
  NeuroImage 2012 Kuceyeski A, Zhang Y, Raj A
• Bayesian algorithm using spatial priors for multiexponential T₂ relaxometry from multiecho spin echo MRI.
  Magnetic resonance in medicine 2012 Kumar D, Nguyen TD, Gauthier SA, Raj A
• T2 prep three-dimensional spiral imaging with efficient whole brain coverage for myelin water quantification at 1.5 tesla.
  Magnetic resonance in medicine 2012 Nguyen TD, Wisnieff C, Cooper MA, Kumar D, Raj A, Spincemaille P, Wang Y, Vartanian T, Gauthier SA
• The wiring economy principle: connectivity determines anatomy in the human brain.
  PloS one 2011 Raj A, Chen YH
• A pilot study of quantitative MRI measurements of ventricular volume and cortical atrophy for the differential diagnosis of normal pressure hydrocephalus.
  Neurology research international 2011 Moore DW, Kovanlikaya I, Heier LA, Raj A, Huang C, Chu KW, Relkin NR
• The generation and validation of white matter connectivity importance maps.
  NeuroImage 2011 Kuceyeski A, Maruta J, Niogi SN, Ghajar J, Raj A
• A fast Edge-preserving Bayesian reconstruction method for Parallel Imaging applications in cardiac MRI.
  Magnetic resonance in medicine 2011 Singh G, Raj A, Kressler B, Nguyen TD, Spincemaille P, Zabih R, Wang Y
• Spatial HARDI: improved visualization of complex white matter architecture with Bayesian spatial regularization.
  NeuroImage 2010 Raj A, Hess C, Mukherjee P
• Visualization and segmentation of liver tumors using dynamic contrast MRI.
  Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2009 Raj A, Juluru K
• A maximum likelihood approach to parallel imaging with coil sensitivity noise.
  IEEE transactions on medical imaging 2007 Raj A, Wang Y, Zabih R
• Fast and stable bayesian image expansion using sparse edge priors.
  IEEE transactions on image processing : a publication of the IEEE Signal Processing Society 2007 Raj A, Thakur K
• Bayesian parallel imaging with edge-preserving priors.
  Magnetic resonance in medicine 2007 Raj A, Singh G, Zabih R, Kressler B, Wang Y, Schuff N, Weiner M
• Automatic algorithm for correcting motion artifacts in time-resolved two-dimensional magnetic resonance angiography using convex projections.
  Magnetic resonance in medicine 2006 Raj A, Zhang H, Prince MR, Wang Y, Zabih R
• Improved signal-to-noise ratio in parallel coronary artery magnetic resonance angiography using graph cuts based Bayesian reconstruction.
  Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference 2006 Singh G, Nguyen T, Kressler B, Spincemaille P, Raj A, Zabih R, Wang Y
• Statistical aspects of parallel imaging reconstruction.
  Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference 2006 Raj A, Kressler B, Singh G, Zabih R, Wang Y