Radioisotope scan used for diagnosing ectopic gastric mucosa in Meckel’s diveiculum: March 2012
**Core Concept**
Meckel's diverticulum is a congenital anomaly of the small intestine, resulting from the incomplete closure of the vitelline duct. Ectopic gastric mucosa within the diverticulum can cause symptoms due to acid production, and diagnosis often relies on imaging studies.
**Why the Correct Answer is Right**
Technetium-99m (99mTc) pertechnetate is a radiopharmaceutical that selectively binds to sialic acid residues on the surface of gastric mucosal cells, allowing for the visualization of ectopic gastric mucosa in Meckel's diverticulum. This binding is specific to gastric mucosa, making 99mTc pertechnetate an ideal agent for diagnosing ectopic gastric mucosa in Meckel's diverticulum.
**Why Each Wrong Option is Incorrect**
**Option A:** Other radioisotopes like 99mTc sulfur colloid are used for liver and spleen imaging, but not specifically for ectopic gastric mucosa.
**Option B:** 99mTc hexamethylpropylene amine oxime (HMPAO) is a radiopharmaceutical used for brain, lung, and bone marrow imaging, but it is not specific for gastric mucosa.
**Option C:** 99mTc pyrophosphate is used for myocardial infarction imaging and bone scintigraphy, but it is not used for Meckel's diverticulum.
**Option D:** 99mTc albumin colloid is used for liver, spleen, and lymph node imaging, but it is not specific for gastric mucosa.
**Clinical Pearl / High-Yield Fact**
Remember that Technetium-99m pertechnetate selectively binds to sialic acid residues on gastric mucosal cells, making it a valuable diagnostic tool for ectopic gastric mucosa in Meckel's diverticulum.
**Correct Answer:** D. 99mTc pertechnetate