Received July 6, 1 979; accepted after revision October 30, 1979. 1Department of Radiology, Division of Nuclear Medicine and Ultrasound, New England Medical Center Hospital, 1 71 Harrison Ave., Boston, MA 021 1 1. Address reprint requests to P. C. Kahn. 2Department of Obstetrics and Gynecology, New England Medical Center Hospital, 1 7i Harrison Ave., Boston, MA 02111. AJR 134:588-589, March 198...