1. From the Departments of Clinical Radiology (N.F., A.N., K. Ishigami, Y.U., D.K., K.M., K. Ishimatsu, H.H.), Advanced Imaging and Interventional Radiology (Y.A.), and Molecular Imaging and Diagnosis (T.N.), Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.