1. From the Department of Radiology, St George’s Hospitals NHS Trust, Blackshaw Rd, London SW17 0QT, England (S.S., J.M., K.S., I.V.); Department of Radiology, Brighton and Sussex University Hospitals NHS Trust, Brighton, England (C.S.); and Department of Radiology, Royal Brompton and Harefield NHS Trust, London, England (A.D.).