1 Department of Diagnostic Radiology (D.Y.O., Y.-W.W., G.C., U.P.), Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
2 Department of Diagnostic Radiology (D.Y.O., Y.-W.W., G.C., U.P.), Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433. Electronic address: druei@yahoo.com.