Delayed 99mTC-Labeled Erythrocyte Scintigraphy in Patients with Lower Gastrointestinal Tract Hemorrhage

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

“…A retrospective study of 67 emergency room patients who had 99m Tc-labeled erythrocyte scintigraphy studies performed with additional delayed imaging, using endpoints of clinical outcome and patient management, compared patients with positive scans to those with negative scans. 123 No statistical significance was found between the 2 groups, and it was concluded that delayed imaging had no significant influence on outcome for those patients whose initial scan (over the course of 1 to 2 hours) was negative or equivocal. These authors report mortality values of 8% for positive scans versus 0% for negative scans, with P Ͻ 0.32 calculated by 2 or Student t-test.…”

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

“…The benefits of delayed imaging, including its effect on patient management such as transfusion requirements, referrals to angiography or surgery, and clinical outcomes, are controversial (68,69). Many investigators have shown that delayed images are not as accurate as early images in localizing the site of gastrointestinal bleeding (30,34,56,68,(70)(71)(72).…”

“…Many investigators have shown that delayed images are not as accurate as early images in localizing the site of gastrointestinal bleeding (30,34,56,68,(70)(71)(72). Some authors advocate imaging patients for as long as possible during the initial phase rather than performing routine delayed imaging at arbitrary intervals hours after injection (10,56).…”

Radionuclide Evaluation of the Lower Gastrointestinal Tract

“…In many cases, the bleeding site can be identified with sufficient confidence to direct surgical intervention or to guide subsequent diagnostic testing (36)(37)(38). Scintigraphy may also provide prognostic information because those patients who require urgent care (surgery or transfusion) often have their bleeding site identified in the first hour (39).…”

“…Images can be reviewed as a cinematic display (47) or by summing the images to make multiple sets of 10-15 min each (or shorter, if needed). If no bleeding site is identified within the first 90 min, delayed images are usually acquired, typically at 2-6 h or 18-24 h after injection (38,48,49).…”