Meckel Scan

Meckel's diverticulum is a common congenital gastrointestinal malformation on the ileum resulting from incomplete atrophy of the vitelline duct in the embryo. The omphalomesenteric duct incompletely regresses to form a blind pouch at the antimesenteric border of the gut. In most cases, it follows the rule of 2, which signifies that it is present in 2% of the population, most cases present before 2-years-old, it's twice as common in males compared to females, it's a 2 inches blind tube that lies about 2 feet from the ileocecal junction, and it contains heterotropic mucosas. Although this is not the case in all the presentations.  The presence of ectopic tissue is associated with symptomatic Meckel's, in which the intestinal mucosa normally found on the ileum also is located in the walls of the Meckel's diverticulum along with gastric tissue or other cases by pancreatic tissue. Infrequently ectopic duodenal and colonic tissue can be present. The most common etiologies of symptomatic Meckel's are intestinal obstruction, gastrointestinal (GI) hemorrhage, and inflammation of the Meckel's with or without perforation. Rarer forms of the disease include umbilical abnormalities involving the vitelline duct and Meckelian cancers.  The diagnosis of Meckel's diverticulum-related diseases is often challenging, with imaging playing an important role in their prompt recognition and differentiation from other common conditions that can have a similar clinical presentation. 99mTc-pertechnetate is taken up by the mucin-producing cells of gastric mucosa and is secreted into the lumen of the gut. The accumulation of these materials in the gastric mucosa makes the scintigraphy the study of choice for identifying ectopic mucosa. The Meckel diverticulum scintigraphy, when used correctly, is an effective method for the detection of Meckel diverticulum with an approximately 100% sensitivity and specificity.  Meckel scintigraphy is indicated to localize ectopic gastric mucosa as the unexplained GI bleeding. This procedure should be used in patients that are not actively bleeding. For active bleeding, a 99mTc-RBC scan is the preferred modality.