HELICAL CT VERSUS CT ARTERIAL PORTOGRAPHY IN THE DETECTION OF HEPATICMETASTASIS OF COLORECTAL-CARCINOMA

OBJECTIVE. The study is a prospective comparison of helical CT with no nhelical CT arterial portography (CTAP) in the detection of liver meta stases from colorectal carcinoma, using surgical and histologic findin gs as the gold standard.SUBJECTS AND METHODS. Thirty-five patients wit h colorectal carcinoma and suspected liver metastases were prospective ly examined with helical CT and CTAP before surgery. In nine cases, su rgery was not performed. In the remaining 26 patients, imaging results were correlated with surgical and pathologic findings. Three radiolog ists prospectively assessed metastatic involvement with both technique s. The results were compared with pathologic and surgical findings on a lesion-by-lesion basis. In a second phase, three radiologists not di rectly concerned in the design of the study independently assessed met astatic involvement of the liver as revealed on helical CT and CTAP on a segment-by-segment basis with a five-level scale of confidence. Res ults were analyzed by receiver operating characteristic methods. RESUL TS. The results of the histologic study disclosed 50 metastatic lesion s. Helical CT had a sensitivity of 76% (38/50) and a positive predicti ve value of 90%. CTAP had a sensitivity of 74% (37/50) and positive pr edictive value of 69%. Receiver operating characteristic analysis reve aled a greater area under the curve (Az index), 0.96, for helical CT t han for CTAP (0.86). Differences were statistically significant (p < . 001), CONCLUSION. Helical CT is superior to nonhelical CTAP in the det ection of hepatic metastases from colorectal carcinoma.