John Onofrey, PhD
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About
Titles
Assistant Professor of Radiology & Biomedical Imaging and of Urology
Biography
Dr. John Onofrey conducts basic research to develop and apply novel software solutions to solve clinical problems by combining data science, machine learning and biomedical imaging. A member of the Departments of Radiology and Biomedical Imaging, Urology, and Biomedical Engineering, Dr. Onofrey is the principal investigator of major research funded by the National Institutes of Health. Currently, his interdisciplinary work addresses challenges in prostate cancer diagnosis, liver cancer staging, and positron emission tomography (PET) image analysis.
Dr. Onofrey’s research focuses on the development of novel image analysis algorithms using machine learning, including deep learning methods, and he has a particular interest in image classification, image segmentation, and image registration. He has applied his background in computer science to a wide variety of medical image analysis research projects. His doctoral research focused on leveraging large amounts of clinical data to build effective statistical models of both brain shape and brain deformation for image-guided neurosurgery. As a postdoctoral researcher, Dr. Onofrey applied machine learning towards interventional image-guided biopsy of prostate cancer. He has also applied state-of-the-art machine learning techniques, including deep learning, to automatically segment anatomical structures from clinical images. Not only did these projects leverage large amounts of data to train complex machine learning software algorithms, but they also required detailed software engineering practices to rigorously test and validate these algorithms.
As an educator, Dr. Onofrey co-created and co-teaches the interdisciplinary “Data and Clinical Decision-Making” class in the School of Engineering, which teaches undergraduate and graduate students, and clinical fellows how data science and machine learning are being applied to real-world clinical problems.
Before coming to Yale in 2007, Dr. Onofrey worked as a professional software engineer for the U.S. Army Research Lab (ARL) and Lockheed Martin. He holds a B.S. and M.S. in Computer Science from Johns Hopkins University and a Ph.D. in Biomedical Engineering from Yale University.
Appointments
Radiology & Biomedical Imaging
Assistant ProfessorFully JointUrology
Assistant ProfessorFully Joint
Other Departments & Organizations
- Bioimaging Sciences
- Center for Biomedical Data Science
- Center for Brain & Mind Health
- Computational Biology and Biomedical Informatics
- Image Processing & Analysis Group
- Magnetic Resonance Research Center
- Radiology & Biomedical Imaging
- Urology
- Yale Biomedical Imaging Institute
- Yale Combined Program in the Biological and Biomedical Sciences (BBS)
Education & Training
- Postdoctoral Associate
- Yale School of Medicine (2016)
- PhD
- Yale University, Biomedical Engineering (2013)
- MPhil
- Yale University, Biomedical Engineering (2009)
- MS
- Yale University, Biomedical Engineering (2008)
- MS
- Johns Hopkins University, Computer Science (2007)
- BS
- Johns Hopkins University, Computer Science (2003)
Research
Publications
Featured Publications
Reliable Prostate Cancer Risk Mapping From MRI Using Targeted and Systematic Core Needle Biopsy Histopathology
Zeevi T, Leapman M, Sprenkle P, Venkataraman R, Staib L, Onofrey J. Reliable Prostate Cancer Risk Mapping From MRI Using Targeted and Systematic Core Needle Biopsy Histopathology. IEEE Transactions On Biomedical Engineering 2024, 71: 1084-1091. PMID: 37874731, PMCID: PMC10901528, DOI: 10.1109/tbme.2023.3326799.Peer-Reviewed Original ResearchMagnetic resonance imagingIndividual patientsBiopsy locationProstate biopsy dataBiopsy histopathologyHistopathology scoresPathology scoresBiopsy dataMRI biomarkersTreatment planPatientsResonance imagingProstate regionBiomarkersTherapy treatment plansPathologyRepresentative sampleScoresImaging analysisPrevious studiesHistopathologyProstateCancerCliniciansAutomated graded prognostic assessment for patients with hepatocellular carcinoma using machine learning
Gross M, Haider S, Ze’evi T, Huber S, Arora S, Kucukkaya A, Iseke S, Gebauer B, Fleckenstein F, Dewey M, Jaffe A, Strazzabosco M, Chapiro J, Onofrey J. Automated graded prognostic assessment for patients with hepatocellular carcinoma using machine learning. European Radiology 2024, 34: 6940-6952. PMID: 38536464, PMCID: PMC11399284, DOI: 10.1007/s00330-024-10624-8.Peer-Reviewed Original ResearchContrast-enhanced magnetic resonance imagingMagnetic resonance imagingClinical staging systemTime of diagnosisHepatocellular carcinomaClinical dataMortality risk predictionOverall survivalStaging systemRadiomic featuresManagement of hepatocellular carcinomaPersonalized follow-up strategiesAssociated with OSMethodsThis retrospective studyHepatocellular carcinoma patientsBaseline magnetic resonance imagingMRI radiomics featuresIndependent validation cohortHarrell's C-indexRisk predictionFollow-up strategiesHigh-risk groupPredictive risk scoreRadiomics feature extractionMedian timeAutomated MRI liver segmentation for anatomical segmentation, liver volumetry, and the extraction of radiomics
Gross M, Huber S, Arora S, Ze’evi T, Haider S, Kucukkaya A, Iseke S, Kuhn T, Gebauer B, Michallek F, Dewey M, Vilgrain V, Sartoris R, Ronot M, Jaffe A, Strazzabosco M, Chapiro J, Onofrey J. Automated MRI liver segmentation for anatomical segmentation, liver volumetry, and the extraction of radiomics. European Radiology 2024, 34: 5056-5065. PMID: 38217704, PMCID: PMC11245591, DOI: 10.1007/s00330-023-10495-5.Peer-Reviewed Original ResearchMagnetic resonance imagingRadiomics feature extractionLiver volumetryIntraclass correlation coefficientRadiomic featuresLiver segmentationAutomated liver volumetryHepatocellular carcinoma patientsMann-Whitney U testAutomated liver segmentationManual segmentationQuantitative imaging biomarkersCarcinoma patientsRetrospective studyInstitutional databaseAnatomical localizationClinical relevanceManual volumetryMann-WhitneyU testExternal validationInternal test setImaging biomarkersInclusion criteriaResultsIn totalIntegrating Prostate Specific Antigen Density Biomarker Into Deep Learning Prostate MRI Lesion Segmentation Models
Zhong J, Staib L, Venkataraman R, Onofrey J. Integrating Prostate Specific Antigen Density Biomarker Into Deep Learning Prostate MRI Lesion Segmentation Models. 2011 IEEE International Symposium On Biomedical Imaging: From Nano To Macro 2023, 00: 1-5. PMID: 38090633, PMCID: PMC10711801, DOI: 10.1109/isbi53787.2023.10230418.Peer-Reviewed Original ResearchFast Reconstruction for Deep Learning PET Head Motion Correction
Zeng T, Zhang J, Lieffrig E, Cai Z, Chen F, You C, Naganawa M, Lu Y, Onofrey J. Fast Reconstruction for Deep Learning PET Head Motion Correction. Lecture Notes In Computer Science 2023, 14229: 710-719. PMID: 38174207, PMCID: PMC10758999, DOI: 10.1007/978-3-031-43999-5_67.Peer-Reviewed Original ResearchCross-Attention for Improved Motion Correction in Brain PET
Cai Z, Zeng T, Lieffrig E, Zhang J, Chen F, Toyonaga T, You C, Xin J, Zheng N, Lu Y, Duncan J, Onofrey J. Cross-Attention for Improved Motion Correction in Brain PET. Lecture Notes In Computer Science 2023, 14312: 34-45. PMID: 38174216, PMCID: PMC10758996, DOI: 10.1007/978-3-031-44858-4_4.Peer-Reviewed Original ResearchDeep learning networkCross-attention mechanismDeep learning benchmarksMotion correctionTraining data domainPET list-mode dataPET image reconstructionQuality of reconstructionData domainCross attentionLearning networkSupervised mannerLearning benchmarksReference imageMotion trackingInherent informationList-mode dataImage reconstructionBrain PET dataPrediction resultsDifferent scannersHead motionImproved motion correctionNetworkSpatial correspondence
2025
Improved Vessel Segmentation with Symmetric Rotation-Equivariant U-Net
Zhang J, Du Y, Dvornek N, Onofrey J. Improved Vessel Segmentation with Symmetric Rotation-Equivariant U-Net. 2025, 00: 1-5. DOI: 10.1109/isbi60581.2025.10981208.Peer-Reviewed Original ResearchConvolutional neural networkU-NetModel sizeSmall memory costMedical image analysisU-Net architectureImproved vessel segmentationTrainable parametersMemory costComputer-assisted interventionSegmentation performanceNeural networkLearning methodsVessel segmentationLearning costLearning approachEquivariance propertyFundus imagesInconsistent predictionsAutomated segmentationImage analysisPerformanceSegmentsImagesArchitectureSRE-CONV: Symmetric Rotation Equivariant Convolution for Biomedical Image Classification
Du Y, Zhang J, Zeevi T, Dvornek N, Onofrey J. SRE-CONV: Symmetric Rotation Equivariant Convolution for Biomedical Image Classification. 2025, 00: 1-5. DOI: 10.1109/isbi60581.2025.10981270.Peer-Reviewed Original ResearchConvolutional neural networkConvolutional neural network backboneComputer vision tasksBiomedical image classificationRotation-invariant featuresReduced memory footprintVision tasksEquivariant convolutionImage classificationIncreased training costsMemory footprintRotation-equivariantData augmentationNeural networkModel sizeTraining costsTest datasetInfor-mationPerformance accuracyParam-etersBiomedical imagingDatasetIncor-poratedEquivarianceModel performanceEnhancing Uncertainty Estimation in Semantic Segmentation via Monte-Carlo Frequency Dropout
Zeevi T, Staib L, Onofrey J. Enhancing Uncertainty Estimation in Semantic Segmentation via Monte-Carlo Frequency Dropout. 2025, 00: 1-5. DOI: 10.1109/isbi60581.2025.10980684.Peer-Reviewed Original ResearchSemantic segmentationDeterministic neural networksChest X-ray scansFeature mapsTraditional dropoutSegmentation taskMC dropoutNeural networkMedical imagesSignal spaceSemantic uncertaintyContrast-enhanced CTEnhance medical decision-makingBiparametric MRIPractical solutionProstate zonesFrequency domainLiver tumorsMonte-CarloX-ray scansUncertainty estimationBoundary delineationMC frequencyTextural variationsImaging modalitiesConditional Convolution of Clinical Data Embeddings for Multimodal Prostate Cancer Classification
Zhong J, Chen F, Chen L, Shung D, Onofrey J. Conditional Convolution of Clinical Data Embeddings for Multimodal Prostate Cancer Classification. 2025, 00: 1-5. DOI: 10.1109/isbi60581.2025.10981307.Peer-Reviewed Original ResearchConvolutional neural networkGleason scoreProstate cancerClinical dataMultiparametric magnetic resonance imagingPredicting Gleason scoreClinical informationCurrent deep learning approachesPatient clinical dataMagnetic resonance imagingDeep learning approachNon-invasive diagnosisAccurate risk predictionData embeddingCNN kernelsMRI scansConditional convolutionPublic datasetsResonance imagingNeural networkProstate cancer classificationData modalitiesLearning approachBaseline modelGS prediction accuracy
Academic Achievements & Community Involvement
News
News
- April 15, 2025
Yale Urology Research [Q1: January-March 2025]
- January 16, 2025
Yale Urology Research [Q4: October-December 2024]
- November 18, 2024
‘Bias in, bias out’: Tackling bias in medical artificial intelligence
- October 30, 2024
Yale Urology Research [Q3: July-September 2024]