Comparison of 99mTc Scintigraphy with Ultrasonic Scanning in the Detection of Liver Disease

Both radioisotope scintigraphy and ultrasonic scanning of the liver are accepted as valuable techniques in the diagnosis of liver disease. The use of 99Tc-S colloid for liver scintigraphy has certain advantages that have been exploited recently. The relative contribution of these two methods to an accurate diagnosis has been compared in normal patients and in patients with cirrhosis of the liver, liver metastases, hepatoma, liver abscess, cysts of the liver, etc. Over five hundred patients were examined by either the ultrasonic technique or the scintigraphic technique, and one hundred patients were examined by both techniques. Certain characteristic appearances were recognized readily and each method separately detected liver abnormality in approximately 85% of instances. When both techniques were applied to the same patient the diagnostic accuracy increased appreciably. Certain advantages of each technique emerged. Radioisotope scintigraphy often gave a more definite picture of liver metastases when the ultrasonic scan was only suggestive of them. Liver abscess and cysts appeared on the scintigraph as filling defects which were indistinguishable from metastases; but on the ultrasonic scan these lesions were clearly fluid filled. Cirrhosis was diagnosed equally well by both techniques. Ultrasonic scanning was more accurate in detecting some diffuse abnormalities, and scintigraphy gave information not otherwise available about the size and shape of the liver and spleen. The value and limitations of the two methods are described. (author)