MedStar Franklin Square Medical Center: 443-777-7406 MedStar Union Memorial Hospital: 877-74-HEART (43278) Bel Air, MD MedStar Radiology Network at Bel Air: 443-625-5430. Clinton, MD MedStar Southern Maryland Hospital Center: 301-877-4766. Leonardtown, MD MedStar St. Mary's Hospital: 301-475-6399. Washington, D.C. MedStar Georgetown ....