Meckel’s Diveiculum is best diagnosed by:
**Core Concept**
Meckel's Diverticulum is a congenital anomaly of the small intestine, resulting from the incomplete closure of the vitelline duct. It is a true diverticulum, containing all layers of the intestinal wall. Meckel's Diverticulum is a common cause of gastrointestinal bleeding in children and adults.
**Why the Correct Answer is Right**
The correct answer is **Technetium-99m Pertechnetate scan**. This scan takes advantage of the fact that the gastric mucosa in Meckel's Diverticulum can produce pepsinogen, which is also produced by the gastric mucosa in the stomach. The Technetium-99m Pertechnetate ion is selectively taken up by the gastric mucosa, making it a useful imaging agent for detecting Meckel's Diverticulum. The scan is highly sensitive and specific for Meckel's Diverticulum, especially when the diverticulum contains ectopic gastric mucosa.
**Why Each Wrong Option is Incorrect**
**Option A:** Ultrasound is not the best diagnostic tool for Meckel's Diverticulum, as it may not detect small diverticula or diverticula without significant mural thickening.
**Option B:** CT scan with oral contrast may show the diverticulum, but it is not the most sensitive or specific imaging modality for Meckel's Diverticulum.
**Option C:** Colonoscopy is not useful for diagnosing Meckel's Diverticulum, as it is located in the small intestine.
**Clinical Pearl / High-Yield Fact**
Remember that Meckel's Diverticulum is a common cause of gastrointestinal bleeding, and a Technetium-99m Pertechnetate scan should be considered in the diagnostic workup of patients with unexplained bleeding.
**Correct Answer:** D. Technetium-99m Pertechnetate scan.