[67Ga]citrate scintiscanning in active inflammatory bowel disease.

Twenty-five hospitalized patients were studied prospectively with [67Ga]citrate (GA) abdominal scintillation scanning in an attempt to define its role in the evaluation of patients with active inflammatory bowel disease (IBD). There were nine patients with ulcerative colitis (UC), seven with Crohn's disease (CD), and nine controls. In four patients, two with UC and two with CD, a tissue/plasma radioactivity ratio was obtained and compared to normals. All the UC patients had positive GA scans and only one of seven of the CD patients had a positive scan. There were no false positive scans. Scans performed after a 3- or 5-day delay were more accurate than 6-hr scans alone. Well-delineated colinic radioactivity 6 hr after injection which persists for 3 to 5 days indicates the presence of UC in patients with IBD, while a negative scan is more consistent with active CD. Colonic uptake at 6 hr which clears by 48 or 72 hr is not indicative of UC. This procedure aided in following the course of UC, delineating the extent of disease, and in differentiating active CD from an intraabdominal abscess. Tissues from UC patients had increased tissue/plasma ratioactivity ratios while tissues from CD patients had normal or decreased ratios which were consistent with the imaging data.