1 Department of Radiology, Boston University Medical Center, 820 Harrison Avenue, FGH-4, Boston, MA 02118 and Boston University School of Medicine, Boston, MA. Electronic address: priscilla.slanetz@bmc.org.
2 Department of Radiology, Johns Hopkins Medicine, 600 N Caroline Street, Baltimore, MD 21297.
4 Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21(st) Avenue South, CCC-1118 Medical Center North, Nashville, TN 37232-2675.