Imaging and Complications of Meckel Diverticulum

Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, yet it is frequently asymptomatic. Meckel diverticulum poses unique diagnostic challenges due to its variable manifestation and infrequent visualization at imaging. The authors review the embryology and anatomy of Meckel diverticulum, its normal radiologic appearances, and its complications and their management. Complications of Meckel diverticulum occur in up to 4%-9% of patients. Symptomatic Meckel diverticulum is more common in children but can also be seen in adults. A giant Meckel diverticulum, presence of ectopic gastric or pancreatic tissue, or adjacent adhesions and bands are associated with a higher likelihood of a symptomatic manifestation. The most common complications include small-bowel obstruction, gastrointestinal bleeding, and diverticulitis. Children more commonly present with gastrointestinal bleeding, while diverticulitis is more common in adults. Small-bowel obstruction can occur at any age and can be secondary to inversion of Meckel diverticulum, intussusception, volvulus, internal or external hernias, neoplasms, enteroliths, congenital bands, or postinflammatory changes. When a patient presents with acute abdomen or gastrointestinal bleeding, the choice of imaging modalities includes CT or US, with the latter preferred in the pediatric population. Technetium 99m-pertechnetate scintigraphy (Meckel scan) can be additionally performed to evaluate rectal bleeding in younger patients. MRI is reserved as a problem-solving tool. Meckel diverticulum should be differentiated from its common imaging mimics (eg, the appendix, ileal duplication cyst, and mesenteric small-bowel diverticulum). When Meckel diverticulum is not visualized at imaging, the radiologist still plays a key role by raising suspicion for an underlying Meckel diverticulum and identifying other critical imaging findings that can inform clinical management. An understanding of the common clinical manifestations associated with Meckel diverticulum and a systematic imaging approach can improve preoperative diagnosis and patient management.