Comparison of unenhanced, hepatic arterial-dominant, and portal venous-dominant phase helical CT for the detection of liver metastases in women with breast carcinoma

OBJECTIVE. The purpose of this study was to evaluate triple-phase helical C T for detection of hepatic metastases from breast carcinoma. SUBJECTS AND METHODS. Breast cancer patients were studied prospectively wit h triple-phase helical CT in 300 consecutive examinations. Hepatic arterial -dominant and portal venous-dominant phase scans were initiated at 20 and 6 5 sec, respectively, after IV injection of 175 ml of iopamidol (30 mg/ml) a t 5 ml/sec. Three independent observers each reviewed 200 cases of the port al venous-dominant phase for lesion number, conspicuity, and attenuation. S ubsequently, portal venous-dominant phase images were reevaluated in conjun ction with hepatic arterial-dominant phase or unenhanced images. RESULTS. Hepatic metastases were identified in 79 (26%) of 300 cases. Lesio ns detected on portal venous-dominant, hepatic arterial-dominant, and unenh anced images were as follows: observer 1, n = 198, 164, and 171; observer 2 , n = 254, 233, and 233; and observer 3, n = 291, 270, and 276 (p > .05). T he mean total lesion count was 387, with more lesions detected on portal ve nous-dominant phase than on either hepatic arterial-dominant phase or unenh anced images (p < .001 and p < .0001, respectively). For individual observe rs, 10-26% of lesions were hypervascular on hepatic arterial-dominant phase images. Two to 4% of lesions were identified only on hepatic arterial-domi nant phase or unenhanced images. However, in these few cases, the lesions e ither were false-positives or were seen in conjunction with additional meta stases on portal venous-dominant images. CONCLUSION. Routine use of triple-phase CT in patients with breast carcinom a may not be warranted: Addition of the hepatic arterial-dominant phase or unenhanced images revealed few additional lesions in our group of 300 patie nts.