Lipiodol computerized tomography: how sensitive and specific is the technique in the diagnosis of hepatocellular carcinoma? Computerized tomography (CT) following the intra-arterial injection of Lipiodol (Lipiodol-CT) was performed on 60 patients suspected of having a hepatocellular carcinoma (HCC). Four main patterns of uptake of the Lipiodol within the liver were seen on CT. Of the 14 well circumscribed lesions with dense homogeneous uptake of Lipiodol, 13 were confirmed to be HCCs. Of the 25 lesions with dense patchy uptake of Lipiodol at the periphery and/or in the centre, 19 were confirmed to be HCCs. In 18 patients, in whom only ill defined faint patchy uptake of Lipiodol was present in the liver, or in whom no hepatic uptake was present at all, only one patient was found later to have an HCC. Of the three hypodense lesions in the liver with no Lipiodol uptake, one was found to be necrotic HCC, one a cholangiocarcinoma and one a regenerative nodule. In the diagnosis of HCC, Lipiodol-CT had an overall sensitivity of 97.1%, an accuracy of 88.3% and a specificity of 76.9%. Of the 34 patients with HCC, only 23 were solitary at diagnosis. The size of the HCCs ranged from 0.8 cm to 11 cm in diameter with the median size at 2.2 cm. Eleven of 34 HCCs (32.3%) were resectable. We conclude that, as part of a screening programme for high risk patients. Lipiodol-CT is useful in the early detection of HCCs. The technique also plays an important role in determining whether the tumour should be resected or managed with chemotherapy. By detecting HCCs while still small, the resectability rate can also be improved. 