Case series review illustrating the utility of SPECT/CT in enhancing reader confidence and avoiding pitfalls in interpreting 99mTc-labeled red blood cell scans

Abstract

Gastrointestinal bleeding is a common condition requiring urgent medical attention. 99mTc-labeled red blood cell scintigraphy is a conventional nuclear medicine imaging technique which is sensitive and noninvasive for diagnosing occult gastrointestinal bleeding. However, there are pitfalls in this technique due to 2D representation in planar images and altered biodistribution in certain physiological status of the patient. The anatomical localization of single-photon emission computerized tomographycomputed tomography (SPECT/CT) can avoid these pitfalls and reduce equivocal findings in Tc99m-labeled red blood cell scintigraphy. This case series review demonstrates equivocal findings in 99mTc-labeled red blood cell scintigraphy, with the help of SPECT/CT, were found to be possible blood pooling in vasculatures and hemolysis after blood transfusion.

Keywords

• Gastrointestinal bleed
• Tc99m-labeled red blood cell scintigraphy
• Single-photon emission computerized tomography-computed tomography (SPECT/CT)