Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Address for correspondence: Kyung Soo Lee, MD. Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine 50, Ilwon-Dong, Kangnam-Ku Seoul 135-710, Korea. Phone: 822-3410-2518, Fax: 822-3410-2559, melon2@samsung.co.kr