The place of hepatobiliary isotope scanning in the diagnosis of gallbladder disease.

The present trend towards a more aggressive operative policy in acute cholecystitis has led to a search for more accurate methods of diagnosis. A possible contender in this field is hepatobiliary isotope scanning. Ninety-nine patients with right-sided upper abdominal pain were studied after the intravenous injection of 99Tcm-pyridoxylideneglutamate. In addition, contrast radiology was performed in 87 of these. Subsequently 23 were shown to have acute cholecystitis, 45 to have other gallbladder disease and 31 to have no evidence of cholecystic pathology. Isotope scanning was found to be reliable when negative at excluding acute cholecystitis (predictive value 100 per cent) and when positive at confirming gallbladder disease (predictive value 100 per cent). In these respects it compared favourably with contrast radiology (corresponding predictive values 80 per cent and 94 per cent) but was greatly inferior for the exclusion of cholelithiasis. A practical method of scanning for routine clinical use is outlined and it is suggested that the method may be clinically useful as a first investigation in those patients presenting with acute right-sided upper abdominal pain. It may also be helpful in confirming pathology in a nonfunctioning gallbladder on oral cholecystography. When the isotope scan is negative (normal) contrast radiology is still required to exclude cholelithiasis. By a combination of the two techniques the correct diagnosis was arrived at in each of the 99 patients studied, suggesting that the methods may have complementary roles.