Steven Tilley, PhD

Contact

steve@steventilley.com

Summary

I have been an imaging researcher since 2009, and have experience in tomographic reconstruction, the design, construction, and characterization of imaging systems, software-hardware interfacing, image processing, and developing pipelines for large scale image analysis.

Education

  1. 2019
    Ph.D. , Biomedical Engineering
    Thesis Title: High-quality computed tomography using advanced model-based iterative reconstruction
    Thesis Advisor: J. Webster Stayman
    Johns Hopkins University
    Baltimore, Maryland
  2. 2012
    B.S. , Biological Engineering
    Thesis Title: Construction and assessment of a high performance four channel multiphoton microscope for deep imaging
    Thesis Advisor: Chris B. Schaffer
    Cornell University
    Ithaca, New York

Professional Experience

  1. 2020-Present
    X-Ray Imaging System and Algorithm Developer
    KA Imaging
    Waterloo, Ontario
  2. 2019-2020
    Imaging Analyst
    Supervisor: Tomáš Paus
    Holland Bloorview Kids Rehabilitation Hospital
    Toronto, Ontario
  3. 2012-2019
    Graduate Researcher
    Advisor: J. Webster Stayman
    Rotation Advisors: Wojciech Zbijewski and Natalia Trayanova
    Johns Hopkins University
    Baltimore, Maryland
  4. 2012-2012
    Temporary Service Technician
    Supervisor: Chris B. Schaffer
    Cornell University
    Ithaca, New York
  5. 2009-2012
    Undergraduate Researcher
    Advisor: Chris B. Schaffer
    Cornell University
    Ithaca, New York

Publications

Theses

  1. Tilley II, S. (2019) "High-quality computed tomography using advanced model-based iterative reconstruction" Ph.D. Dissertation, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland link
  2. Tilley II, S. (2011) "Construction and assessment of a high performance four channel multiphoton microscope for deep imaging" Undergraduate Honors Thesis, Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York

Journal Articles

  1. Bares, A. J., Mejooli, M. A., Pender, M. A., Leddon, S. A., Tilley, S., Lin, K., Dong, J., Kim, M., Fowell, D. J., Nishimura, N., and Schaffer, C. B. (2020) "Hyperspectral multiphoton microscopy for in vivo visualization of multiple, spectrally overlapped fluorescent labels" Optica Vol: 7, DOI: 10.1364/OPTICA.389982
  2. Liu, S. Z., Cao, Q., Tivnan, M., Tilley II, S. W., Siewerdsen, J. H., Stayman, J. W., and Zbijewski, W. (2020) "Model-based dual-energy tomographic image reconstruction of objects containing known metal components" Physics in Medicine & Biology DOI: 10.1088/1361-6560/abc5a9
  3. Hehn, L., Tilley II, S., Pfeiffer, F., and Stayman, J. W. (2019) "Blind deconvolution in model-based iterative reconstruction for CT using a normalized sparsity measure" Physics in Medicine and Biology Vol: 64, DOI: 10.1088/1361-6560/ab489e PMCID: PMC6936101
  4. Tilley II, S., Zbijewski, W., and Stayman, J. W. (2019) "Model-based material decomposition with a penalized nonlinear least-squares CT reconstruction algorithm" Physics in Medicine and Biology DOI: 10.1088/1361-6560/aaf973 link
  5. Tilley II, S., Jacobson, M., Cao, Q., Brehler, M., Sisniega, A., Zbijewski, W., and Stayman, J. W. (2017) "Penalized-likelihood reconstruction with high-fidelity measurement models for high-resolution cone-beam imaging" IEEE Transactions on Medical Imaging Vol: 37, pp: 988-999 DOI: 10.1109/TMI.2017.2779406 arXiv: 1712.05297
  6. Tilley II, S., Siewerdsen, J. H., and Stayman, J. W. (2016) "Model-based iterative reconstruction for flat-panel cone-beam CT with focal spot blur, detector blur, and correlated noise" Physics in Medicine and Biology Vol: 61, pp: 296 DOI: 10.1088/0031-9155/61/1/296 PMCID: PMC5011041 arXiv: 1706.05418

Conference proceedings

Oral Presentations

  1. Tilley II, S., Zbijewski, W., and Stayman, J. W. (2018) "A general CT reconstruction algorithm for model-based material decomposition" SPIE Medical Imaging Vol: 10573, DOI: 10.1117/12.2293776
  2. Tilley II, S., Siewerdsen, J. H., Zbijewski, W., and Stayman, J. W. (2016) "Nonlinear statistical reconstruction for flat-panel cone-beam CT with blur and correlated noise models" SPIE Medical Imaging Vol: 9783, DOI: 10.1117/12.2216126 PMCID: PMC4837455
  3. Tilley II, S., Siewerdsen, J. H., and Stayman, J. W. (2015) "Generalized penalized weighted least-squares reconstruction for deblurred flat-panel CBCT" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. pp: 236-239 link

Poster Presentations

  1. Tilley II, S., Sisniega, A., Siewerdsen, J. H., and Stayman, J. W. (2018) "High-fidelity modeling of detector lag and gantry motion in CT reconstruction" Proc. 5th Intl. Mtg. on Image Formation in X-ray CT pp: 318-322 arXiv: 1805.11631
  2. Tilley II, S., Zbijewski, W., and Stayman, J. W. (2017) "High-fidelity modeling of shift-variant focal-spot blur for high-resolution CT" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. pp: 752-759 arXiv: 1706.08946
  3. Tilley II, S., Zbijewski, W., Siewerdsen, J. H., and Stayman, J. W. (2016) "Modeling shift-variant X-ray focal spot blur for high-resolution flat-panel cone-beam CT" Proc. 4th Intl. Mtg. on Image Formation in X-ray CT PMCID: PMC5370169 arXiv: 1610.05288
  4. Tilley II, S., Siewerdsen, J. H., and Stayman, J. W. (2014) "Iterative CT reconstruction using models of source and detector blur and correlated noise" Proc. 3rd Intl. Mtg. on Image Formation in X-ray CT pp: 363-367 PMCID: PMC4207223

Coauthor

  1. Tivnan, M., Tilley II, S., and Stayman, J. W. (2019) "Physical modeling and performance of spatial-spectral filters for CT material decomposition" SPIE Medical Imaging Vol: 10948, pp: 312 - 317 DOI: 10.1117/12.2513481
  2. Tivnan, M., Wang, W., Tilley II, S., Siewerdsen, J. H., and Stayman, J. W. (2019) "Optimized spatial-spectral CT for multi-material decomposition" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. Vol: 11072, pp: 172 - 176 DOI: 10.1117/12.2534333 PMCID: PMC7654953
  3. Liu, S. Z., Tilley II, S., Cao, Q., Siewerdsen, J. H., Stayman, J. W., and Zbijewski, W. (2019) "Known-component model-based material decomposition for dual energy imaging of bone compositions in the presence of metal implant" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. Vol: 11072, pp: 182 - 186 DOI: 10.1117/12.2534725
  4. Wang, W., Tilley II, S., Tivnan, M., and Stayman, J. W. (2019) "Local response prediction in model-based CT material decomposition" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. Vol: 11072, pp: 162 - 166 DOI: 10.1117/12.2534437
  5. Stayman, J. W. and Tilley II, S. (2018) "Model-based multi-material decomposition using spatial-spectral filters" Proc. 5th Intl. Mtg. on Image Formation in X-ray CT pp: 102-105 link
  6. Cao, Q., Brehler, M., Sisniega, A., Tilley II, S., Bhruwani, M. M. S., Stayman, J. W., Yorkston, J., Siewerdsen, J. H., and Zbijewski, W. (2018) "High-resolution extremity cone-beam CT with a CMOS detector: evaluation of a clinical prototype in quantitative assessment of bone microarchitecture" SPIE Medical Imaging Vol: 10573, DOI: 10.1117/12.2293810
  7. Zhang, X., Tilley II, S., Xu, S., Mathews, A., McVeigh, E. R., and Stayman, J. W. (2017) "Deformable known component model-based reconstruction for coronary CT angiography" SPIE Medical Imaging Vol: 10132, DOI: 10.1117/12.2255303
  8. Bares, A., Pender, M. A., Mejooli, M. A., Tilley II, S., Chen, K. E., Dong, J., Doerschuk, P. C., and Schaffer, C. B. (2016) "Hyperspectral imaging in live mouse cortex using a 48-channel multiphoton microscope" Frontiers in Optics pp: FTh5D.5 DOI: 10.1364/FIO.2016.FTh5D.5
  9. Mathews, A. J., Tilley II, S., Gang, G., Kawamoto, S., Zbijewski, W., Siewerdsen, J. H., Levinson, R., and Stayman, J. W. (2016) "Design of dual multiple aperture devices for dynamical fluence field modulated CT" Proc. 4th Intl. Mtg. on Image Formation in X-ray CT PMCID: PMC5370167
  10. Bares, A., Tilley II, S., Doerschuk, P. S., and Schaffer, C. B. (2015) "Hyperspectral multiphoton microscopy: demonstration of 48-channel imaging in vivo" Frontiers in Optics pp: FTu2D.5 DOI: 10.1364/FIO.2015.FTu2D.5
  11. Zbijewski, W., Cao, Q., Tilley II, S., Sisniega, A., Stayman, J. W., Yorkston, J., and Siewerdsen, J. H. (2015) "Quantitative assessment of bone and joint health on a dedicated extremities cone-beam CT system" International Journal of Computer Assisted Radiology and Surgery Vol: 10, pp: S29-S31 PMCID: PMC4451217
  12. Stayman, J. W., Zbijewski, W., Tilley II, S., and Siewerdsen, J. (2014) "Generalized least-squares CT reconstruction with detector blur and correlated noise models" SPIE Medical Imaging Vol: 9033, DOI: 10.1117/12.2043067 PMCID: PMC4201055
  13. Stayman, J. W., Tilley II, S., and Siewerdsen, J. H. (2014) "Integration of component knowledge in penalized-likelihood reconstruction with morphological and spectral uncertainties" Proc. 3rd Intl. Mtg. on Image Formation in X-ray CT pp: 111-115 PMCID: PMC4211110
  14. Zbijewski, W., Xu, J., Tilley II, S., Stayman, J. W., Taguchi, K., Fredenberg, E., and Siewerdsen, J. H. (2013) "Volumetric imaging with sparse arrays of photon counting silicon strip detectors" Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med. pp: 276-279 link

Conference Abstracts

Oral Presentations

  1. Tilley II, S. and Stayman, J. W. (2018) "Model-based material decomposition for acquisitions with relaxed spectral and spatial sampling" The American Association of Physicists in Medicine Annual Meeting link

Coauthor

  1. Mahmood, F., Borders, D., Chen, R., Sweer, J., Tilley II, S., Nishioka, N. S., Stayman, J. W., and Durr, N. J. (2019) "Robust photometric stereo endoscopy via deep learning trained on synthetic data" Multimodal biomedical imaging XIV Vol: 10871, DOI: 10.1117/12.2509878
  2. Wang, W., Tivnan, M., Gang, G. J., Tilley II, S., and Stayman, J. W. (2019) "Generalized local impulse response prediction in model-based material decomposition of spectral CT" The American Association of Physicists in Medicine Annual Meeting link
  3. Tivnan, M., Wang, W., Tilley II, S., and Stayman, J. W. (2019) "Designing Spatial-Spectral Fitlers for Spectral CT" The American Association of Physicists in Medicine Annual Meeting (submitted) link
  4. Zbijewski, W., Cao, Q., Brehler, M., Tilley II, S., Sisniega, A., Stayman, J. W., and Siewerdsen, J. H. (2018) "High-resolution imaging of bone health" Bulletin of the American Physical Society link
  5. Bares, A. J., Tilley II, S., Mejooli, M. A., Pender, M. A., Doerschuk, P. C., and Schaffer, C. B. (2016) "In vivo imaging of multiple cell types in murine cortex using 48-channel hyperspectral multiphoton microscopy" SPIE Photonics Europe link

Invited Talks and Seminars

Oral Presentations

  1. Tilley II, S. (2018) "Improving image quality and accuracy in flat-panel cone-beam CT using model-based iterative reconstruction with high-fidelity system and noise models" Center for Imaging Science Seminar Series, Johns Hopkins University
  2. Tilley II, S. (2018) "A general CT reconstruction algorithm for model-based material decomposition" BME Student Seminar Series, Johns Hopkins University

Coauthor

  1. Zbijewski, W., Cao, Q., Tilley II, S., Brehler, M., Sisniega, A., Stayman, J. W., and Siewerdsen, J. H. (2018) "Quantitative cone-beam CT: new technologies, algorithms, and applications in orthopedic imaging" SIAM Conference on Imaging Science link

Other

Oral Presentations

  1. Tilley II, S. and Paus, T. (2019) "Comparing two tissue classification algorithms for MRI image analysis" Canada-Norway Summer School
  2. Tilley II, S., Siewerdsen, J. H., and Stayman, J. W. (2015) "High resolution CBCT with blur and correlated noise models in a non-linear reconstruction algorithm" The 5th Annual Hopkins Imaging Conference, Johns Hopkins University

Poster Presentations

  1. Liao, Z., Tilley II, S., Khairullah, A., and Paus, T. (2020) "An Interplay Between Pubertal and Adult Testosterone and Brain Response to Faces in Young Men" Organization for Human Brain Mapping (accepted)
  2. Tilley II, S. and Schaffer, C. B. (2011) "Construction of a high efficiency four channel 2 photon excited fluorescence microscope" 26th Annual Undergraduate Spring Research Forum, Cornell University

Patents

  1. Bares, A. J., Schaffer, C. B., and Tilley, S. (2019) "Hyperspectral multiphoton microscope for biomedical applications" US Patent 10394008 link

Funding and Awards

  1. 2017-2019
    F31 EB023783
    "Model-based reconstruction for high-spatial resolution cone-beam computed tomography"
    ~$87,000
    National Institute of Biomedical Imaging and Bioengineering
  2. 2017
    Travel Award
    Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med.
  3. 2015
    Travel Award
    Intl. Mtg. Fully 3D Image Recon. in Radiology and Nuc. Med.
  4. 2012-2014
    T32 EB010021
    "Training program in translational research in imaging"
    ~$44,000
    National Institute of Biomedical Imaging and Bioengineering
  5. 2010
    Undergradute Research Award
    "Design and construction of a four-channel two-photon excited fluorescence microscope"
    Engineering Learning Initiatives

Professional Activities

Peer Review

  1. Computers in Biology and Medicine (1 review)
  2. Human Brain Mapping (2 reviews)
  3. IEEE Transactions on Biomedical Engineering (1 review)

Other

  1. 2013
    Director
    3rd Annual Hopkins Imaging Conference
    Baltimore, Maryland

Teaching Experience

  1. 2016
    Teaching Assistant
    Imaging Instrumentation
    Johns Hopkins University
    Baltimore, Maryland
  2. 2015
    Teaching Assistant
    Models and Simulations
    Johns Hopkins University
    Baltimore, Maryland

Volunteering and Outreach

  1. 2013
    Classroom Volunteer
    Friendship Academy of Science and Technology
    Baltimore, Maryland