About the Author
Thomas H. Shawker, M.D.
, is chief of the ultrasound section in the Imaging Sciences Program at the National Institutes of Health, a professor of radiology at the United Services University, and a fellow of the American College of Radiology. He is chairman of the National Genealogical Society's Family Health and Heredity Committee and president of the Prince George's County Genealogical Society. He is the author or coauthor of over two hundred scientific publications and a speaker on both medical and genealogical topics. He and his wife live in Maryland.