Predictive value of technetium Tc 99m-labeled red blood cell scintigraphy for positive angiogram in massive lower gastrointestinal hemorrhage

Abstract

Patients with immediate blush on 99mTc-labeled red blood cell scintigraphy required urgent angiography. Patients with delayed blush have low angiographic yields. These data suggest that patients with delayed blush or negative scans may be observed and evaluated with colonoscopy.

Lower gastrointestinal bleeding: therapeutic strategies, surgical techniques and results

“…Although a specificity of up to 94%, with a sensitivity of 95%, has been reported [37], other authors cite a significant rate of incorrect localization [38,33,39]. We suggest caution in recommending limited colonic resection on the basis of a positive red blood cell scan only.…”

The SNMMI Procedure Standard/EANM Practice Guideline for Gastrointestinal Bleeding Scintigraphy 2.0

“…Some excreted radioactivity may be seen in the urinary tract because of small amounts of free 99m Tc-pertechnetate and other 99m Tc moieties even when in vitro labeling is used (65). The initial angiographic-phase images rarely reveal the site of rapid gastrointestinal bleeding, which may be difficult to localize on the subsequent dynamic images, or a vascular blush in neoplasms, arteriovenous malformations, or angiodysplasia (52,66,67).…”

Does Hemodynamic Instability Predict Positive Technetium-Labeled Red Blood Cell Scintigraphy in Patients With Acute Lower Gastrointestinal Bleeding? A Review of 50 Patients

“…Last, the literature is plagued with questions of immediate vs. delayed positivity as it relates to interpreting the scans. 9,10 Nonetheless, there is a body of literature strongly supporting the use of tagged RBC scintigraphy in the setting of acute lower gastrointestinal bleeding. 3,9 This dichotomy can be explained, in part, by the fact that these nuclear studies are operator-dependent and the surgeon's ability to act on the basis of a tagged RBC scan depends on the confidence in the study obtained.…”