Stephen (Hyun) Kim

  • Research Professor

Stephen (Hyun) Kim

Dr. Kim’s research focuses on the development of mathematical and computational models of transport-related biological systems, which includes characterization of light-tissue interaction, 3D tomographic imaging of physiologically relevant parameters in biological systems such as oxy-hemoglobin and deoxy-hemoglobin, 3D molecular imaging, and modeling of chemical species transport.

Dr. Kim has been applying these models and related technologies in preclinical and clinical studies that focus on the ultrahigh spatiotemporal resolution direct imaging of neuronal brain imaging, diagnosis of rheumatoid arthritis and Lupus in finger joints, the early detection and treatment monitoring of breast cancer, imaging of prostate cancer and risk stratification, cancer diagnostics and drug efficacy based on fluorescence and bioluminescence molecular imaging, assessment of peripheral arterial disease, Melanoma early diagnosis, and detection and monitoring of infantile hemangiomas.

Research Interests: Computational modeling; Biological transport systems; Light-tissue interactions; Tomographic image reconstruction; Functional Brain Imaging; Breast Cancer and Treatment Monitoring; Lupus and Arthritis Imaging; Vascular Imaging; Skin Cancer and Prostate Cancer Imaging; Small Animal Imaging; Bioluminescence and Fluorescence Molecular Imaging

Columbia University, New York, 2020-2022 Associate Professor, Department of Radiology

Columbia University, New York, 2011-2019 Assistant Professor, Department of Radiology

Columbia University, New York, 2009-2011
Associate Research Scientist, Department of Biomedical Engineering


Columbia University, New York, 2006-2008
Postdoctoral Research Scientist, Department of Biomedical Engineering

Korea Advanced Institute of Science & Technology (KAIST), South Korea, 2001-2004 PhD, Department of Mechanical Engineering

Korea Advanced Institute of Science & Technology (KAIST), South Korea, 1999-2001 MS, Department of Mechanical Engineering


1. H.K. Kim, Y. Zhao, A. Raghuram, J. T. Robinson and A. N. Veeraraghavan, A.
Hielscher, " Ultrafast and Ultrahigh-Resolution Diffuse Optical Tomography for Brain Imaging with Sensitivity Equation based Noniterative Sparse Optical Reconstruction (SENSOR)," accepted to Journal of Quantitative Spectroscopy and Radiative Transfer, 107939 (2021)
2. Y. Zhao, A. Raghuram, H.K. Kim, A. Hielscher, J. T. Robinson and A. N. Veeraraghavan, "High Resolution, Deep Imaging Using Confocal Time-of-flight Diffuse Optical Tomography," IEEE Transactions on Pattern Analysis and Machine Intelligence (2021), doi: 10.1109/TPAMI.2021.3075366.
3. L. Altoe, K. Kalinsky, A. Marone, H.K. Kim, Hua Guo, H. Hibshoosh, M. Tejada, Ka. Crew, M. Accordino, M. Trivedi, D. Hershman, and A.H. Hielscher, “Changes in diffuse-optical-tomography images during early stages of neoadjuvant chemotherapy correlate with tumor response in different breast cancer subtypes, Clinical Cancer Research 27(7):1949-1957 (2021)
4. Y. Kim, A. Marone, G. Danias, W. Tang, H.K. Kim, A.D. Askanase, I. Kymissis, A.H. Hielscher, “A flexible optical imaging band system for the assessment of arthritis in patients with systemic lupus erythematosus,” Biomedical Optics Express 12, 1651- 1665 (2021)
5. M.L. Altoe, K. Kalinsky, A. Marone, H. K. Kim, Hua Guo, H. Hibshoosh, M. Tejada, Ka. Crew, M. Accordino, M. Trivedi, D. Hershman, and A.H. Hielscher, “Effects of neoadjuvant chemotherapy on the non-tumor bearing breast assessed by diffusion optical tomography,” Breast Cancer Research 23(1):16 (2020).
6. M. L. Altoe, A. Marone, H. K. Kim, K. Kalinsky, D. L. Hershman, A. H. Hielscher, and R. S. Ha, "Diffuse optical tomography of the breast: a potential modifiable biomarker of breast cancer risk with neoadjuvant chemotherapy," Biomed. Opt. Express 10, 4305- 4315 (2019)
7. A. Marone, J. W. Hoi, M. A. Khalil, H. K. Kim, G. Shrikhande, R. Dayal, D. R. Bajakian, and A. H. Hielscher, "Modeling of the hemodynamics in the feet of patients with peripheral artery disease," Biomedical Optics Express 10, 657-669 (2019).
8. J. E. Gunther, E. A. Lim, H. K. Kim, M. Flexman, M. Altoé, J. A. Campbell, H. Hibshoosh, K. D. Crew, K. Kalinsky, D. Hershman, A. H. Hielscher, “Dynamic Diffuse Optical Tomography for Monitoring Neoadjuvant Chemotherapy in Patients with Breast Cancer,” Radiology 287(3), 778-786 (2018).
9. J. W. Hoi, H. K. Kim, C. J. Fong, L. Zweck, and A. H. Hielscher, "Non-contact dynamic diffuse optical tomography imaging system for evaluating lower extremity vasculature," Biomedical Optics Express 9, 5597-5614 (2018).
10. E. A. Lim, J. E. Gunther, H. K. Kim, M. Flexman, H. Hibshoosh, K. Crew, B. Taback, J. Campbell, K. Kalinsky, A. H. Hielscher, L. L. Hershman, “Diffuse optical tomography changes correlate with residual cancer burden after neoadjuvant chemotherapy in breast cancer patients,” Breast Cancer Research and Treatment 162, 533-540 (2017).
11. H. K. Kim, L. Montejo, J. Jia, A. H. Hielscher, “Frequency-domain optical tomographic image reconstruction algorithm with the simplified spherical harmonics (SP3) light propagation model”, International Journal of Thermal Science 116, 265–277 (2017).
12. H. K. Kim*, J. Jia*, A. H. Hielscher, “Fast linear solver for radiative transport equation with multiple right hand sides in diffuse optical tomography”, Journal of Quantitative Spectroscopy and Radiative Transfer 167, 10-22 (2015).(*Equal Contribution)
13. M. Khalil, H. K. Kim, J. W. Hoi, I. Kim, R. Dayal, G. Shrikhande, A. H. Hielscher, “Detection of Peripheral Arterial Disease Within the Foot Using Vascular Optical Tomographic Imaging,” European Journal of Vascular and Endovascular Surgery 49(1), 83-89 (2015).
14. J. H. Lee, H. K. Kim, C. Chandhanayingyong, F. Y. Lee, A. H. Hielscher, “Non-Contact Small Animal Fluorescence Imaging System for Simultaneous Multi-directional Angular-dependent Data Acquisition,” Biomedical Optical Express 5(7), 2301-16 (2014).
15. M. L. Flexman, H. K. Kim, J. E. Gunther, E. A. Lim, M. C. Alvarez, E. Desperito, A. H. Hielscher, “Optical biomarkers for breast cancer derived from dynamic diffuse optical tomography”, Journal of Biomedical Optics, 18(9) (2013).
16. L. D. Montejo, J. Jia, H. K. Kim, U. J. Netz, S. Blaschke, G. A. Muller, A. H. Hielscher,”Computer-aided diagnosis of rheumatoid arthritis with optical tomography”, Part 2: image classification. Journal of Biomedical Optics 18 076002 (2013)
17. L. D. Montejo, J. Jia, H. K. Kim, U. J. Netz, S. Blaschke, G. A. Muller, A. H. Hielscher, "Computer-aided diagnosis of rheumatoid arthritis with optical tomography, Part 1: feature extraction." Journal of Biomedical Optics 18, 076001 (2013)
18. S. R. Sirsi, M. L. Flexman, F. Vlachos, J. Huang, S. L. Hernandez, H. K. Kim, T. B. Johung, J. W. Gander, A. R. Reichstein, B. S. Lampl, A. Wang, A. H. Hielscher, J. J. Kandel, D. Y. Yamashiro, M. A. Borden, “Contrast Ultrasound Imaging for Identification of Early Responder Tumor Models to Anti-Angiogenic Therapy”, Ultrasound in Medicine and Biology 38(6), 1019-1029 (2012).
19. M. A. Khalil, H.K. Kim, I.-K. Kim, M. Flexman, R. Dayal, G. Shrikhande, A. H. Hielscher, “Dynamic diffuse optical tomography imaging of peripheral arterial disease”, Biomedical Optics Express 3, Issue 9, pp. 2288-2298 (2012).
20. H. K. Kim*, M. Flexman*, R. Stoll, M. Khalil, C. Fong, A. Hielscher, “A wireless handheld probe with spectrally-constrained evolution strategies for absolute chromophore measurements and dynamic imaging”, Journal of Biomedical Optics 17, 016014 (2012). (*Equal Contribution)
21. M. L. Flexman, F. Vlachos, H. K. Kim, J. Huang, S. L. Hernandez, T. J. Johung, J. Gander, A. Reichstein, B. S. Lampl, A. Wang, D. J. Yamashiro, J. J. Kandel, A. H. Hielscher, “Monitoring early tumor response to drug therapy with diffuse optical

tomography and magnetic resonance imaging”, Journal of Biomedical Optics 17,
016014 (2012).
22. M. L. Flexman, H. K. Kim, .E. Lim, E. Desperito, R. R. Barbour, D. Hershman, A. H.
Hielscher “Detecting Breast Cancer with Dynamic Diffuse Optical Tomographic Imaging”, Cancer Research 71(24), Supplement 3, doi: 10.1158/0008-5472.SABCS11- P2-10-09 (2011).
23. M. L. Flexman, M. A. Khalil, R. A. Abdi, H. K. Kim, C. J. Fong, R. R. Barbour, E. Desperito, D. Hershman, A. H. Hielscher, “Digital optical tomography system for dynamic breast imaging”, Journal of Biomedical Optics 16, 076014 (2011).
24. A. H. Hielscher, H. K. Kim, L. Montejo, S. Blaschke, U. Netz, P. Zwaka, G. Müller, J. Beuthan , “Frequency domain optical tomographic imaging of finger joints” , IEEE Transactions on Medical Imaging 99, pp. 1, (2011)
25. H. K. Kim, M. Flexman, D.J. Yamashiro, J. Kandel, and A.H. Hielscher, “PDE- constrained Multispectral Imaging of Tissue Chromophores Concentrations with the Equation of Radiative Transfer,” Biomedical Optics Express 1(3), 812-824 (2010).
26. H. K. Kim, A.H. Hielscher, “A diffusion-transport hybrid method for frequency domain optical tomography,” Journal of Innovative Optical Health Sciences 3, 1–13 (2010).
27. H. K. Kim, A.H. Hielscher, “A PDE-constrained SQP algorithm for optical tomography based on the frequency-domain equation of radiative transfer,” Inverse Problems 25, 015010 (2009).
28. H. K. Kim, U. Netz, J. Beuthan, A.H. Hielscher, “Optimal source-modulation frequencies for transport-theory-based optical tomography of small-tissue volumes,” Optics Express 16, 18082–18101(2008).
29. H. K. Kim, J. Lee, A.H. Hielscher, “PDE-constrained fluorescence tomography with the frequency-domain equation of radiative transfer,” IEEE Journal of Selected Topics in Quantum Electronics 16, 793-803 (2010).


  1. JH Lee, HK Kim, LIM Emerson, AH Hielscher, “Transrectal Diagnostic Device,” US Patent

    App. 16/303,706, published as US20200008737A1 on 2020-01-09.

  2. AH Hielscher, M Khalil, R Dayal, IK Parrack, HK Kim, “Dynamic Optical Tomographic

    Imaging Devices Methods and Systems,” US Patent App. 16/216,137, published as

    US20190282134A1 on 2019-09-19.

  3. AH Hielscher, ML Flexman, R Stoll, HK Kim, “Compact Optical Imaging Devices, Systems,

    and Methods,” US Patent App. 16/129,925, published as US20190239751A1 on 2019-

    08-08.

  4. AH Hielscher, CJ Fong, J Hoi, HK Kim, M Khalil,” Monitoring Treatment of Peripheral

    Artery Disease (PAD) Using Diffuse Optical Imaging,” US Patent App. 16/093,775,

    published as US20190125195A1 on 2019-05-02.

  5. HK Kim, AH Hielscher, “Tomographic Imaging Methods, Devices, and Systems,” US

    Patent App. 16/211,693, published as US20190110024A1 on 2019-04-11.

  6. A.H. Hielscher, H.K. Kim, L.D. Montejo, S. Blaschke, U.J. Netz, G.A. Mueller, J. Beuthan,,

    “Medical Imaging Devices, Methods, and Systems,” Korean Application No. 2013-

7018117, based off PCT/US2011/064723 filed December 12, 2011, allowed September

27, 2018. (patent number pending)

  1. H.K. Kim, A.H. Hielscher, “Tomographic Imaging Methods, Devices, and Systems,“ U.S.

    Application No. 14/356,924 filed May 8, 2014; based from PCT/US2012/064163 filed

    November 8, 2012, allowed September 19, 2018. (patent number pending)

  2. A.H. Hielscher, C.J. Fong, J. Hoi, H.K. Kim, M. Khalil, M. Khalil, “Monitoring treatment of peripheral artery disease (pad) using diffuse optical imaging,“ PCT/US2017/029027 filed

    2017-04-23, WO2017189376A1 filed 2017-11-02.

  3. J.H. Lee, H.K. Kim, E. Lim, A.H. Hielscher, “Transrectal Diagnostic Device,” (PTC/US2017/

    034800, WO2017205808A1), Application filed 2016-05-27, published 2017-05-26.

  4. A.H. Hielscher, H.K. Kim, L. D. Montejo, “Systems, methods, and devices for image

    reconstruction using combined PDE-constrained and simplified spherical harmonics algorithm,” (PCT/US2013/071269), US Patent No. 9,495,516 (issued November 15, 2016).

  5. A.H. Hielscher, M. Khalil, R. Dayal, I.-K. Kim, H.K. Kim, “Dynamic Optical Tomographic Imaging Devices, Methods, and Systems,” Atty. Docket No. T4356-19064WO01, T4356- 18602US01; PCT/US2011/060489, US 13/876,861) US Patent No. 9,429,089 (issued November 15, 2016); Announcement to intention to grant by European Patent Office on June 15, 2015.

  6. A.H. Hielscher, H.K. Kim, L. D. Montejo, “Medical Imaging Devices, Methods, and Systems,” Atty. Docket No. T4356-18601US01, PCT/US2011/064723, US 13/993,592), US Patent No. 9,486,142 (issued November 8, 2016)

13. H.K. Kim, A.H. Hielscher, “Tomographic Imaging Methods, Devices, and Systems,” (Columbia Invention Report # CU12119, PCT/US2012/064163, Application # US 14/356,924), filed November 8, 2012; National filings for US, Korea, Japan, and Europe submitted May 8, 2014; published October 23, 2014 (Publication No. 20,140,313,305)

  1. A.H. Hielscher, M.L. Flexman, R. Stoll, H.K. Kim, “Compact optical imaging devices, systems, and methods,” (CU12093, PCT/US2012/058065, US 14/348,081), filed September 28, 2012; published August 28, 2014. (Publication No. 20,140,243,681)

  2. A.H. Hielscher, H.K. Kim, L. D. Montejo, S. Blaschke, U. Netz, G.A. Mueller, J. Beuthan, “Medical Imaging Devices, Methods, and Systems,” (CU invention reports # M11-007 and M11-122, PCT/US2011/064747, US 13/993,578,) filed Dec 13, 2011; published on March 27, 2014 (Publication No. 20,140,088,415)