Below are thin section CT images in the mid abdomen:

A blind ending structure in the mid abdomen just to the right of midline is identified, originating from the distal small bowel and demonstrating thickened hyperenhancing mucosa. There is also an endoscopic capsule in the transverse colon.

The patient was administered Tc99m pertechnetate and dynamic anterior imaging was performed:

This patient has a symptomatic Meckel’s diverticulum. This diverticulum has ectopic gastric mucosa, which both causes symptoms due to inflammation/intermittent bleeding and results in the positive imaging findings seen in this case.

This is a challenging diagnosis to make on CT. Among imaging exams with a known Meckel’s diverticulum, CT has been found to identify the diverticulum in 57% of symptomatic patients and 42% of asymptomatic patients. Inflammatory changes such as wall thickening (Meckel’s diverticulitis) are frequently the identifiable abnormality, but cases may also present with small bowel obstruction or intraluminal contrast extravasation.

Tc99m pertechnetate has normal uptake in the gastric mucosa, and so identification of Meckel’s diverticulum with this examination is dependent on gastric mucosa being present (10-30% of diverticuli). Gastric mucosa is present in 60% of symptomatic patients and 98% of those with bleeding. A large retrospective study of more than 900 patients showed sensitivity of 85% and specificity of 95% for detecting gastric mucosa. However false negative (e.g. small or infarcted diverticulum) and false positive (e.g. duplication cysts, inflammatory bowel disease) tests do occur.

Kawamoto S, et al. CT detection of symptomatic and asymptomatic Meckel’s diverticulum. AJR 2015;205:281-91.
Sfakianakis GN, et al. Detection of ectopic gastric mucosa in Meckel’s diverticulum and in other aberrations by scintigraphy. J Nucl Med 1981;22:647-54.
Ziessman HA, O’Malley JP, Thrall JH, eds. Nuclear Medicine, the Requisites, 4th ed. Philadelphia: Elsevier, 2014.