Imaging diagnosis of hepatoma

Nuclear medicine (NM), ultrasonography (US), and computed tomography (CT) were evaluated as screening methods for hepatoma, and the characteristics of each modality were compared. Qualitative diagnosis of hepatoma by measuring the quantitative time-lapse changes in 67Ga-citrate accumulation was also investigated. A prospective analysis using the above modalities was conducted for 70 patients with hepatoma, with the following results: sensitivities of NM, US and CT were 91.1% ; 91.8% ; and 96.9% respectively. In comparing the characteristics of the three modalities, however, it was concluded that the combined use of NM and US was recommended for screening, and that CT should be used for more detailed examination of a tumor indicated by NM and/or US. In the diagnosis of hepatoma by 67Ga-citrate, a sensitivity rate of 73.7% and a specificity rate of 92.5% were obtained, indicating 67Ga-citrate's considerable significance for qualitative diagnosis of hepatoma. A decision tree was also made for those patients with chronic liver disease in whom positive hepatitis B virus (HBV) infection was detected or in whom serum alpha-fetoprotein (AFP) showed an increasing tendency. (author)