Evaluation of delayed contrast enhanced CT scan in diagnosing hilar cholangiocarcinoma / 中华放射学杂志

ABSTRACT

Objective To assess the diagnostic value of delayed CT contrast enhancement patterns in hilar cholangiocarcinoma based on two phased dynamic incremental CT scanning. Methods Fifty two patients with suspected hilar tumor and bile duct obstruction underwent spiral CT scan. The scan time for one revolution of the X ray tube was 1 second. To elucidate the delay time for optimal imaging, all proved cholangiocarcinoma with delayed (6、8、10、15、20、30 minutes) post equilibrium phase contrast enhanced CT scans were acquired with unenhanced, dynamic contrast enhanced, and delayed images. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Results (1) 8～15 minutes after IV injection of contrast material was the delay time for optimal imaging. (2) Of 29 cholangiocarcinomas, the early CT showed hypoattenuating (lower than that of liver parenchyma) in 23 tumors, isoattenuating (equal to that of the liver) in 4 tumors, and hyperattenuating (higher than that of liver) in 2 tumors. The delayed CT scan showed isoattenuating in 8 tumors, hyperattenuating in 21 tumors, and no hypoattenuating. Most of delay imaging of hilar cholangiocarcinoma may appear hyperattenuating ( U=-4.307 3, P