Doris Lin, MD

The Metropolitan Vascular Institute is a state-of-the-art outpatient facility located in Waldorf, MD that specializes in vascular conditions such as End Stage Renal Disease, Peripheral Artery Disease, Varicose Veins, and Men's & Women's Health. We have a team of multi-specialty medical providers who will help you assess and treat your vascular health.

Karen M. Horton, M.D., is a Professor of Radiology and the Chair of Radiology for the Russell H. Morgan Department of Radiology and Radiological Science. Dr. Horton’s clinical and research focus is on abdominal CT imaging, 3D imaging of the gastrointestinal tract and the mesenteric vessels, and virtual colonoscopy. She has published over 170 scientific papers, numerous book chapters and was the Johns Hopkins principle investigator in the National CT Colonography Trial. Dr. Horton graduated summa cum laude from the University of Notre Dame in 1988. She attended the Johns Hopkins University School of Medicine, graduating in the top 10 percent of her class and was inducted into the AOA honor society. After completing a radiology residency and a fellowship in cross-sectional imaging at Johns Hopkins, Dr. Horton joined the radiology faculty as an assistant professor in 1998. Dr. Horton was promoted to Associate Professor in 2002, and in 2008 became the 144th female to be promoted to Professor at Johns Hopkins. In 2009, Dr. Horton assumed the role of Johns Hopkins Radiology Residency Program Director. During her more than four years as program director, the residency program was ranked #1 by Aunt Minnie twice and #4 by Doximity. During her tenure, in addition to making significant improvements to the residency curriculum, she increased diversity by recruiting more women and underrepresented minorities. From 2013 to 2014, Dr. Horton served as Acting Chair of the Department of Radiology at the Johns Hopkins Bayview Medical Center. Dr. Horton established subspecialty divisions and more fully integrated the Johns Hopkins Bayview Medical Center and The Johns Hopkins Hospital radiology divisions. She is a member of the Johns Hopkins Kimmel Cancer Center. Dr. Horton has held numerous leadership positions within the Department of Radiology and Radiological Science, including Vice Chair of Operations in 2014, Executive Vice Chair in 2015, Interim Chair in 2016-2017.

Dr. David Valle is a professor of pediatrics and ophthalmology at the Johns Hopkins School of Medicine and former director of the Johns Hopkins Department of Genetic Medicine. He also serves as a geneticist for the Johns Hopkins Children’s Center.Dr. Valle holds a bachelor’s degree and medical degree from Duke University. He completed a pediatric residency at Johns Hopkins University before joining the Johns Hopkins faculty. He is interested in the genetic contributions to health and disease. He is the founding director of the Johns Hopkins Center for Inherited Disease Research. Over the years, his laboratory has discovered the genetic causation for more than 20 diseases, including those responsible for inborn errors of metabolism, inherited retinal degeneration, disorders of cellular organelle biogenesis and genetic variations that contribute risk for common disorders such as schizophrenia.Dr. Valle also serves as director of the Predoctoral Training Program in Human Genetics, as well as co-director of the Genes to Society program. He was a 2014 recipient of the annual Victor A. McKusick Leadership Award from the American Society of Human Genetics, which recognizes individuals whose professional achievements have fostered and enriched the development of human genetics as well as its assimilation into the broader context of science, medicine and health.