Radiology, Vol 138, 177-184, Copyright © 1981 by Radiological Society of North America
Complementary role of Tc-99m-diethyl-IDA and ultrasound in large and small duct biliary tract obstruction
WC Klingensmith 3d, ML Johnson, CC Kuni, MG Dunne and AR Fritzberg
Fifty-one patients underwent both radionuclide and ultrasound studies of
the hepatobiliary system. Eleven patients had large bile duct obstruction,
six had intrahepatic diffuse small duct obstruction, and 37 had no
obstruction. In all 11 patients with large duct obstruction, the
radionuclide images were abnormal, but in nine of these studies the level
of obstruction could not be determined. Ultrasound was abnormal in nine
studies (with correct identification of level), normal in one, and
technically inadequate in one, ultrasound scans were also abnormal in six
patients without obstruction. In small duct obstruction, the radionuclide
scan was abnormal in all six, but in five patients it could not
differentiate small from large duct obstruction. In all six patients,
ultrasound showed no large duct obstruction, thus allowing identification
of the level of obstruction in patients whose radionuclide scans were
equivocal. A cost analysis indicated that in suspected large duct
obstruction, the best strategy is ultrasound first, followed by
radionuclide imaging in all positive or technically inadequate ultrasound
studies. In suspected small duct obstruction, the best strategy is
radionuclide scanning first followed by ultrasound in all
Tc-99m-diethyl-IDA studies equivocal as to level of obstruction.
