Joyoni Deydey

Associate Professor

Ph.D. in Electrical and Computer Engineering, 1999 - Carnegie Mellon University

Louisiana State University
Department of Physics & Astronomy
437 Nicholson Hall, Tower Dr.
Baton Rouge, LA 70803-4001
225-578-4289-Office
225-578-9048-Lab
deyj@lsu.edu

Teaching

  • Fall: MedP 7111: Advanced Medical Imaging Physics
  • Spring: MedP 4111: Introduction to Medical Imaging
  • Spring: (Co-Instructor): Radiological Physics for Residents (LSU Health Sc)

Patents

  • J. Dey and S.J. Glick, "SPECT Camera Design", Patent No., US 8,519,351 B2, Aug 27, 2013. 
  • J. Dey, N. Bhusal, L. Butler, J. P. Dowling, K. Ham, V. Singh, "Phase Contrast X-ray Interferometry" US Patent No., 10872708 B2 , Dec 22, 2020.
  • J. Dey, N. Bhusal, L. Butler, J. Dowling, K. Ham and V. Singh, Patent No. US 11,488,740 B2, Nov 1, 2022. 

Students

Ph.D.

  • Murtuza Taqi (Current, MSc/PhD)
  • Hunter Meyer (Graduation Spring 2026, MSc/PhD). Best in Physics (Imaging), 2024, 66th AAPM, C. M. Smith Superior Graduate Student Scholarship in Medical Physics 2025-2026, Coates Research Scholar Award 2025, 2026
  • Jingzhu Xu (PhD Graduated, May 2020). Coates Research Scholar Award, 2019

MSc

  • Lacey Medlock  (Graduation, Fall 2023)
  • Bryce Smith (Graduated, Summer 2023)
  • Sydney Carr (Graduated, Summer 2023)
  • Ivan Hidrovo (Graduated, Summer 2022)
  • Elizabeth Park (Graduated, Summer 2022)
  • Hanif Soysal (Graduated, Summer 2019)
  • Narayan Bhusal (Graduated, December 2018)  

Undergraduate

  • Althaf H. Salaavudeen (DOD/NSF ASSURE/REU, Summer 2025-present)
  • Tejasvi Tyagi Undergrad at Stanford (Summer 2025-present)
  • Varun Gala Undergrad at UCSB (Summer 2025-present)
  • Conner Klebrowski (Summer 2025)
  • Conner Dooley (NSF REU, Summer 2024)
  • Victoria Fontenot (Summer 2024)
  • Bryce Smith (2019-2020, Summer 2020)
  • Ivan Hidrovo (2016, 2017, 2018 )
  • Megan Chesal (2016, 2017, 2018)
  • David Sanchez (NSF REU, Summer 2017)

Research

Research Interests: medical imaging, image processing, Xray/CT interferometry imaging, imaging system design and optimization for improving sensitivity and specificity, reducing patient dose and/or imaging time, image reconstruction with physical modeling for artifact removal and quantification, mathematical (PDE) models of tumor growth and treatment  for oncological prediction and staging, machine learning and AI for disease prediction, artifact removal, denoising and other tasks.

Selected Projects

X-ray Interferometry

X-ray interferometry not only provides attenuation images provided by conventional X-ray/CT but also small angle scatter and differential phase images, affording additional soft-tissue contrast in images compared to conventional CT. We are investigating a novel modulated phase grating (MPG) system to bring Phase Contrast X-ray a step closer to the clinic.

Example Relevant Publications/Patents (* indicates direct grad- or undergrad- students guided by Dey)

    • H. C. Meyer*, J. Dey, C. B. Dooley*, M. S. Taqi*, V. R. Gala*, C. Morrison, V. L. Fontenot*, K. Ham, L. G. Butler, A. Noël, "Moiré Artifact Reduction in Grating Interferometry Using Multiple Harmonics and Total Variation Regularization", Scientific Reports, April 2026, https://doi.org/10.1038/s41598-026-48167-1
    • H. Meyer*, J. Dey, S. Carr*, K. Ham, L. Butler, K. M. Dooley, I. Hidrovo*, Markus Bleuel, T. Varga, J. Schulz, T. Beckenbach, and K. Kaiser, “Theoretical and experimental analysis of the modulated phase grating X-ray interferometer”, Scientific Reports, Nov 2024, https://doi.org/10.1038/s41598-024-78133-8 
    • H. Meyer*, J. Dey, K. Ham, L. Butler, K. Dooley, A. Nöel, (2024, July 21-25), Best in Physics (Imaging): Investigating the Modulated Phase Grating Interferometer for Lung and Breast Cancer Screening, [Oral presentation, Lung Functional Imaging and Analysis], in 66th Annual Meeting & Exhibition of the American Association of Physicists in Medicine (AAPM) in Los Angeles, CA, United States. https://aapm.confex.com/aapm/2024am/meetingapp.cgi/Paper/12189
    • I. Hidrovo*, S. Carr*, K. Ham, L. G. Butler, A. Roy, J. Dey, “Observation of fringe patterns from a modulated phase grating x-ray interferometry system,” Proc. SPIE vol. 12031, Medical Imaging 2022: Physics of Medical Imaging, 120313L (2022) https://doi.org/10.1117/12.2611814
    • E. Park*., J. Xu*, J. Dey, “Hybrid modulated-phase-grating for phase contrast x-ray for a varyingfringe period clinical interferometry system”, Proc. SPIE vol. 12031, Medical Imaging 2022: Physics of Medical Imaging; 120313N (2022) https://doi.org/10.1117/12.2611610
    • J. Xu*, K. Ham, J. Dey, “X-ray Interferometry without Analyzer for Breast CT Application, a Simulaton Study”, J. of Medical Imaging, vol. 7, no. 2, 023503 (2020), https://doi:10.1117/1.JMI.7.2.023503.
    • J. Dey, N. Bhusal*, L. Butler, J. P. Dowling, K. Ham, V. Singh, "Phase Contrast X-ray Interferometry" US Patent No., 10872708 , Dec 22, 2020
    • J. Dey, N. Bhusal*, L. Butler, J. Dowling, K. Ham and V. Singh, Patent No. US 11,488,740 B2, Nov 1, 2022

Breast Imaging

Individualized glandular fraction estimate for Breast Mammography. Individualized Dosimetry to follow.

Example Relevant Publications (* indicates direct grad-students guided by Dey)

    • B. Smith*, J. Dey, L. Medlock*, D. Solis, K. Kirby, "Maximum-Likelihood Estimation of Glandular Fraction for Mammography and its Effect on Microcalcification Detection", submitted to Physical and Engineering Sciences in Medicine, accepted for publication, April 21, 2025, preprint: https://doi.org/10.48550/arXiv.2304.09272

    • B. Smith*, J. Dey, “Maximum-likelihood estimation of thickness with a linear-scatter model for mammography”, Proc. SPIE vol. 12031, Medical Imaging 2022: Physics of Medical Imaging; 120311Y (2022); https://doi.org/10.1117/12.2611970

Machine-Learning/Deep-learning applications to Imaging

Example Relevant Publications (* indicates direct undergrad or grad-students guided by Dey)

    • T. Tyagi*, A. H. Salavudeen*, C. Klebrowski*, J. Dey “A Probabilistic Alzheimer’s Risk Model based on Tau-Pet SUVR for a patient subgroup”, in Proc. SPIE 13924, Medical Imaging 2026: Physics of Medical Imaging, 1392444 (2 April 2026); https://doi.org/10.1117/12.3087858
    • A. H. Salavudeen*, T. Tyagi*, C. Klebrowski*, J. Dey. “Subset Stratification for Predictive Alzheimer’s Models using Tau-PET SUVR”, in Proc. SPIE 13924, Medical Imaging 2026: Physics of Medical Imaging, 1392443 (2 April 2026); https://doi.org/10.1117/12.3087847
    • J. Dey, J. Xu*, and B. Smith*, "Investigation of artifacts due to large-area grating defects and correction using short window Fourier transform and convolution neural networks for phase-contrast x-ray interferometry", Proc. SPIE 11312, Medical Imaging 2020: Physics of Medical Imaging, 113124Z (16 March 2020); https://doi.org/10.1117/12.2549409
    • Staging preclinical SPECT/CT data using support vector machine using key radiomic features (student Megan Chesal honors thesis, April 2018)

Mathematical Tumor Modeling

We investigated tumor progress and disease treatment monitoring by extracting biophysical-model-parameters from images: Oncology Imaging is performed using modalities including CT, MRI, FDG-PET, SPECT etc. Applying realistic mathematical models to serial-images of tumors extracts biologically relevant information from images, such as cell-motility, growth-rate etc. We build a mathematical Finite Element tumor-model where effects of the necrotic core are considered in addition to cell-motility, growth, apoptosis and migration. We also acquired 6 preclinical serial SPECT/CT datasets and fitted an existing ode compartmental volume model. 

Example Relevant Publications (* indicates direct grad or undergrad-students guided by Dey, ** indicates direct postdocs mentored by Dey)

Cardiac SPECT System Design and Optimization

Optimizing a Novel Gamma Camera design for Cardiac SPECT: We investigated a high-sensitive and/or high-resolution gamma-camera design with a system of Ellipsoid detectors with pinhole collimation for Cardiac SPECT, which is an important modality for assessing myocardial perfusion with millions of patients undergoing nuclear cardiology scans per year. In course of our research, we have built a comprehensive multi-pinhole system simulator and iterative reconstruction.

Example Relevant Publications/Patents (* indicates direct grad students guided by J. Dey, ** indicates direct postdocs) 

 

LSU