Andrew Kai-Chun Cheng1, Siu-Chun Wong2, Wendy Pui-Man Wong1, Yan-Lin Li3, Stephen Chi Wai Cheung1. 1. Department of Radiology, Queen Mary Hospital, Pok Fu Lam, Hong Kong. 2. Department of Radiology, Princess Margaret Hospital, Kowloon, Hong Kong. 3. Department of Radiology, Queen Mary Hospital, Pok Fu Lam, Hong Kong. jyl.li@mensa.org.hk.