Computed tomography of focal hepatic lesions: a blind clinical evaluation of the effect of contrast enhancement.

Hepatic CT scans in 61 consecutive patients with proved liver metastasis performed both before and after administration of contrast medium were subjected to blind analysis by two observers. In 10 patients (16%) hepatic lesions were better defined before CE and focal hepatic lesions were diagnostically visible only before CE in 8 patients (13%). Lesions were better defined following CE in 16 patients (26%) but in only 2 cases (3%) were lesions diagnostically visible only after CE. The majority of lesions [35 (58%)] were equally well visualized before and after CE.