The clinical utility of nuclear medicine imaging for the detection of occult gastrointestinal haemorrhage

Abstract

Acute gastrointestinal bleeding is often intermittent and the bleeding source may be difficult to locate, resulting in delay of potentially life-saving treatment. The aim of this study was to determine the clinical utility of 99mTc labelled red blood cell imaging and [99mTc]pertechnetate (Meckel's scan) imaging in a series of 137 patients admitted over a 5 year period to hospital for management of acute gastrointestinal bleeding. Of the 137 patients, 70 had positive 99mTc red blood cell studies. Eleven of 24 patients who had imaging performed beyond 3 h had positive scans that would otherwise have been missed. Only 47 patients had a definite final diagnosis at the time of hospital discharge, of which six were negative on 99mTc red blood cell imaging. The correct site of bleeding was localized in seven of 21 patients with foregut bleeding, and 15 of 20 patients with colonic bleeding. Endoscopy yielded a diagnosis in 13 of the 47 patients (28%). Eleven patients had Meckel's scans but all were negative. Angiography was diagnostic in one of 17 patients studied. 99mTc red blood cell imaging is a useful test in the management of acute gastrointestinal bleeding. Imaging beyond 3 h may further improve the bleeding detection rate. This test, however, may be an unreliable means of localization of bleeding, particularly in the foregut.

Nonvariceal upper gastrointestinal bleeding

“…Gunderman et al had an overall positive scintigraphic screening in 46% of the 249 patients undergoing 99mTc-RBC scans over a 10-year study period [30]. Similar positive scintigraphic screening rates ranging from 46-73% have been confirmed [31,[66][67][68]. Jacobson and Cerqueira showed that upper sources of bleeding in the stomach or small bowel were more common when the nuclear screening studies became positive on delayed imaging [31].…”

Gastroenterologic and Radiologic Approach to Obscure Gastrointestinal Bleeding: How, Why, and When?

“…First, the ability to localize the source of bleeding with radionuclide scanning, especially in the foregut, has been repeatedly demonstrated to be poor; even a positive scan does not allow determination of the cause of the bleeding. In addition, because nuclear scanning is not therapeutic, a follow-up study, such as catheter-directed angiography or endoscopic examination, must be subsequently performed (24).…”

Wireless capsule endoscopy: a comparison with push enteroscopy in patients with gastroscopy and colonoscopy negative gastrointestinal bleeding

“…2 5 Angiography is rarely helpful unless the patient is actively bleeding at a rate of more than 3-5 ml/min 2 5 12 and scintigraphy with technetium labelled red cells is of limited value, particularly in the foregut. 13 Meckel scans are helpful when positive, but if negative do not exclude a Meckel's diverticulum as a bleeding source.…”