1 University of Florida, Department of Radiology, College of Medicine, University of Florida, Post Office Box 100374, Gainesville, Florida 32610-0374. Electronic address: vermnu@radiology.ufl.edu.
2 University of Massachusetts Medical School-Baystate, Springfield, Massachusetts.
3 University of Florida, Department of Radiology, College of Medicine, University of Florida, Gainesville, Florida.
4 Boston University School of Medicine, Boston, Massachusetts.