Abstract. Eighty-three patients, submitted for investigation of the liver due to persistently elevated activities of serum aminotransferases were included in a study in order to compare the relative merits of liver biopsy, ultrasound and radionucleide imaging.

From the liver biopsy it was found that 45 patients had fatty liver, 14 had cirrhosis and 11 had chronic inflammation, 3 had haemochromatosis and 10 had unspecific changes or normal findings.

An investigation with ultrasound yielded pathological findings in 65% of the patients. The sensitivity was highest in patients with fatty liver (82%) and more than 10% fat in the liver always resulted in increased echogeneicity. Alterations in the liver due to cirrhosis and chronic inflammation were detected with ultrasound in only 50% and 57% of the cases, respectively.

Radionucleide imaging was positive in 44% of the patients with fatty liver, 64% of those with cirrhosis and 21% of the patients with chronic inflammation. It was only possible to distinguish fatty liver from cirrhosis in those patients who had an increase in the size of the spleen (four patients).

The study demonstrates that in patients with a persistent elevation of serum aminotransferases ultrasound has a high sensitivity for detecting more than 10% fat in the liver. However, both the ultrasound and a liver scintigram had a rather low sensitivity and a very low specificity for making a diagnosis for this group of patients. With the aid of a liver biopsy it was possible to establish a diagnosis in 90% of the patients.