Pitfalls of a99mTc-RBC bleeding study due to gallbladder and ileal-loop visualization

Abstract

A series of 99mTc-labeled red blood cell (RBC) scintigrams in a patient with a past history of radiation proctitis demonstrated incidental findings of gallbladder activity, probably related to multiple blood transfusions and renal failure. Variable activity in an ileal-loop urinary diversion simulating bowel pooling was also noted. Thus, difficulties encountered in scan interpretation are presented.

Efficacy of liver graft washout as a function of the perfusate, pressure, and temperature

“…Despite the comparable 99m Tc‐pertechnetate kinetics in rats and humans, more rapid elimination in the rat biliary system was found. Radioactive biliary excretion in the gallbladder or ileal loop after RBC labeling in humans is a rare finding, but it has been observed 24 hours after the administration of 99m Tc‐pertechnetate . Although rats do not have a gallbladder, a pinhole collimator–equipped camera revealed radioactive bile being excreted into the duodenum after approximately 20 minutes in our experiments.…”

“…Radioactive biliary excretion in the gallbladder or ileal loop after RBC labeling in humans is a rare finding, but it has been observed 24 hours after the administration of 99m Tc-pertechnetate. [30][31][32][33][34] Although rats do not have a gallbladder, a pinhole collimator-equipped camera revealed radioactive bile being excreted into the duodenum after approximately 20 minutes in our experiments. With a mean bile flow of 0.6 lL/g of liver/minute in rats, 35 accumulation in the intrahepatic biliary tract occurred before visualization by the pinhole camera; as a result, higher residual radioactivity could be found in the liver after washout.…”

Gallbladder visualization on Tc-99m-labeled red cell scintigraphy: A rare finding with an emphasis on role of single-photon emission computed tomography/computed tomography

“…[5] Till now, only a few cases of gallbladder visualization during 99m Tc-labeled RBC scintigraphy for occult GI bleed have been reported in the literature. [6789] The common conditions among the previously reported and current study are chronic renal disease and multiple blood transfusions to treat the severe anemia. One of the reasons for the gallbladder visualization is attributed to the bile labeling, probably due to the breakdown of hemoglobin to bilirubin.…”

The Role of Nuclear Medicine in the Detection of Acute Gastrointestinal Bleeding

“…Gallbladder visualization during 99m Tc-labeled erythrocyte scintigraphy has been more widely reported in both adults and a neonate. [73][74][75][76][77][78] Hematobilia may account for this scan finding, or alternatively transfusion-related labeling of the porphyrin group of degraded hemoglobin, with subsequent liver and biliary excretion, particularly in patients with severe renal impairment. 73,79 Not only does 99m Tc-labeled erythrocyte scintigraphy have the potential to detect active bleeding from gastrointestinal tumors, but it also may help demonstrate other large vascular tumors.…”