Diagnosis of sclerosing cholangitis with technetium 99m-labeled iminodiacetic acid planar and single photon emission computed tomographic scintigraphy

The purpose of this study was to determine whether ^99mTc-iminodiacetic acid planar biliary scintigraphy combined with single photon emission computed tomography could detect sclerosing cholangitis and provide additional information regarding the extent and severity of disease. Thirteen patients with sclerosing cholangitis and 13 normal control subjects were studied. Scintigraphic results were also compared with previously reported studies of patients with isolated common bile duct obstruction and with primary biliary cirrhosis. The planar scintigraphy in patients with sclerosing cholangitis showed beading or bandlike constrictions of the biliary tract corresponding to lesions seen on cholangiography, and the image pattern was distinctly different from images obtained from patients with isolated common bile duct obstruction or primary biliary cirrhosis. The single photon emission computed tomography images of the liver in patients with sclerosing cholangitis demonstrated multiple focal areas of ^99mTc-iminodiacetic acid retention, representing bile stasis in intrahepatic bile ducts. Compared to controls, the mean hepatic clearance half-time of ^99mTc-iminodiacetic acid was markedly delayed in patients with sclerosing cholangitis (6-10 times normal). Individual patients with sclerosing cholangitis had wider variation in isotope clearance half-time from three regions of the liver than patients with isolated common bile duct obstruction, consistent with regionaJ differences in disease severity and variable impairment of bile flow. In 4 patients with sclerosing cholangitis with incomplete filling of the right and left hepatic ducts at cholangiography, planar and single photon emission computed tomographic scintigraphy provided evidence of significant intrahepatic sclerosing cholangitis. In conclusion, combined ^99mTc-iminodiacetic acid planar and single photon emission computed tomographic scintigraphy is a sensitive noninvasive test for the diagnosis of sclerosing cholangitis and reliably differentiates sclerosing cholangitis from isolated common bile duct obstruction or primary biliary cirrhosis. Measurement of isotope clearance half-time provides quantitative physiologic data that may be useful in the longitudinal follow-up of patients with sclerosing cholangitis.