In a prospective study, an attempt was made to determine the specificity of various imaging methods for defining tumours of the liver rather than their ability to demonstrate them. It was based on 130 patients with histologically confirmed lesions (33 haemangiomas, 17 FNH, 4 hepatocellular adenomas, 28 HCC, 36 adenocarcinoma metastases). The methods were MRT (130 cases), sonography (119), CT (122), dynamic arterial angio-CT (15), 99TC-EHIDA or blood pool scintigraphy (4 FNH, haemangiomas, HCC, 44 cases). MRT showed somewhat better results (accuracy 80%) than CT (73%) and angio-CT (73%) in demonstrating the type of lesion. The results of scintigraphy (53%) and sonography (69%) were rather worse. The range of accuracy for MRT, CT and sonography varied from 94% (haemangiomas with MRT) to 47% (FNH with sonography).