Tc-99m Mebrofenin Hepatobiliary Scan in Obstructive Hepatobiliary Disease: Determining Causes with Early and Late Delayed Imaging

Hepatobiliary radionuclide imaging is typically performed to detect cholecystitis. Infrequently, imaging reveals an obstructive pattern. Although delayed hepatobiliary imaging is commonly used to differentiate between intrahepatic (IH) and extrahepatic (EH) obstruction in the newborn; there is room to clarify the use of delayed imaging in the adult population. A retrospective review was performed of adult patients demonstrating a complete obstructive pattern on initial Tc-99m mebrofenin hepatobiliary imaging. Delayed imaging was divided into early delayed (ED) (<10 h) and late delayed (LD) (≥10 h) imaging. Two physicians qualified the presence of intestinal radiotracer (negative, low to high) on delayed images. Determination of EH or IH pathology was obtained from chart review. A total of 24 patients demonstrated an obstructive pattern using delayed Tc-99m mebrofenin hepatobiliary imaging, with delayed imaging ranging from 4 to 30 h. EH pathologies (choledocholithiasis, stricture, other) represented 63% of cases (n = 15), IH pathologies (cirrhosis, hepatitis, other) represented 33% cases (n = 8) and 1 case was indeterminate. 67% of EH cases showed intestinal activity on delayed imaging (67% on ED and 67% on LD imaging), whereas 63% of IH cases showed intestinal activity on delayed imaging (67% on ED imaging and 60% on LD imaging). The presence of intestinal activity on the both the early and delayed images did not differentiate between the IH and EH pathology groups. Subdividing the groups into ED imaging and LD imaging was also not predictive of determining location of obstructive pattern on the initial 1 h of imaging. This data suggests that delayed hepatobiliary scintigraphy has little or no role in determining the cause of obstructive pathology.