DOUBLE-PHASE CT ARTERIOGRAPHY OF THE WHOLE LIVER IN THE EVALUATION OFHEPATIC-TUMORS

Purpose: Our goal was to evaluate the contribution of double phase CT arteriography (CTA) of the whole liver to differentiate hepatic tumors from false-positive areas on CT during arterial portography (CTAP). M ethods: In 38 candidates for surgical resection of hepatic tumors, bot h CTAP and double phase CTA were performed. A total of 68 perfusion de fects were identified at CTAP. Of 68 perfusion defects, 47 were found to represent hepatic tumors [hepatocellular carcinoma (HCC), n = 31: h epatic metastasis, n = 13; cholangiocarcinoma, n = 2; focal nodular hy perplasia, n = 1]. The other 21 perfusion defects were defined as perf usion abnormalities in which focal hepatic masses had not been identif ied at surgery or pathologic analysis. The phase one CTA scanning star ted 12 s after the beginning of the injection of contrast material, an d the phase two CTA scanning started 20 s after the end of the phase o ne CTA, with 60 ml of contrast agent (150 mg I/ml) injected at a rate of 2 ml/s. Results: On phase one CTA, only 1 lesion in 31 HCCs showed rim enhancement and 26 HCCs (84%) had rim enhancement on phase two CTA . Twelve lesions (80%) of the hepatic metastases and cholangiocarcinom as had rim enhancement on phase one CTA and 11 lesions (73%) showed ri m enhancement on phase two CTA. Twenty-one perfusion abnormalities on CTAP did not show rim enhancement on either phase one or phase two CTA . Conclusion: Double phase CT arteriography of the whole liver was use ful to differentiate hepatic tumors from perfusion abnormalities on CT AP.