1. From the Departments of Diagnostic Radiology (A.C.M., A.K.H., S.Y., S.R.P.) and Pathology (N.S.R.), The University of Texas MD Anderson Cancer Center, 1400 Pressler St, Unit 1473, Houston, TX 77030-4009; Department of Radiology, University of Texas at San Antonio, San Antonio, Tex (V.S.K.); and Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, Pa (A.K.D.).