1. From the Center for Health Science Innovation (D.U.) and Department of Diagnostic and Interventional Radiology, Graduate School of Medicine (Y. Mitsuyama, H. Takita, D.H., S.L.W., H. Tatekawa, Y. Miki), Osaka Metropolitan University, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.