1. From the Department of Diagnostic Radiology (S.W., C.N.T., P.-L.K.), The University of Hong Kong; the Laboratory of Biomedical Imaging and Signal Processing, Department of Electrical and Electronic Engineering (E.X.W., H.-F.L.), The University of Hong Kong; and the Department of Pediatric and Adolescent Medicine (P.-T.C.), The University of Hong Kong, Hong Kong.