Dr. Shepherd received his PhD from the Engineering Physics Program (Physics/Electrical Eng/Mechanical Eng) at the University of Virginia. He did a postdoctoral fellowship in Biophysics at Princeton University designing cameras and experimental setups for time-resolved macromolecular protein crystallography. After a short industry position as Principal Scientist at a large medical imaging company, he joined the faculty of the Radiology Department at the University of California San Francisco. Since 2018, he has been leading a research group at the University of Hawaii Cancer Center studying novel imaging biomarkers including dual-energy X-ray Absorptiometry (DXA) scan for bone density and body composition, mammography for breast density and tissue textural measures as risk factors for breast cancer, and 3-D optical whole body scanning for quantifying body shape as a risk factor for metabolic diseases. Using these modalities, he uses advanced statistical methods to extract more information from images. The methods include principal component analysis and deep convolution neural networks. His major cancer center projects and products are listed here (https://shepherdresearchlab.org) and include:

- Hawaii Pacific Mammography Registry (HIPIMR) - He is the director of the registry that curates imaging and clinical risk factors for breast cancer. The registry contains the cancer outcomes of over 100k women in Hawaii since 2009. 

- Makawalu Study - He is the Principal Investigator of this study to develop low-cost and accessible breast cancer screening programs in the US API. This project involves the development of a real-time AI-informed portable breast ultrasound system where the AI models are integrated into the hardware. This is a potential capstone project. 

- Artificial Intelligence Precision Health Institute (AI PHI) - He directs this institute to further the use of artificial intelligence in medical research. 

- Shape Up Cohort - He is the Principal Investigator of the Shape Up Cohort which studies how body shape is associated with health. 

He also holds five patents in quantitative imaging. His group has been expert consultants for the NHANES study DXA component for 20 years. He has published over 300 peer-reviewed papers, is a Fulbright Scholar, and is a past president of the International Society for Clinical Densitometry.