From the Guidelines
The problem is in the vitelline duct, also known as the omphalomesenteric duct, which is associated with Meckel's diverticulum, a condition that can be diagnosed using a Technetium-99m pertechnetate scan. This scan is utilized to investigate for a Meckel diverticulum, as described in the study by 1, which involves the intravenous administration of 99mTc pertechnetate that accumulates in gastric mucosa often found ectopically in a Meckel diverticulum. The technique of the scan includes dynamic scintigraphy for 30–60 minutes to identify a fixed abdominal region of ectopic gastric mucosa.
The Meckel scan is particularly useful in cases of unexplained gastrointestinal bleeding, especially in children and young adults, as most symptomatic Meckel diverticula are found in this population, although it can occasionally be seen in older individuals, as noted in the study by 1. The scan works because Meckel's diverticulum often contains ectopic gastric mucosa that secretes acid, and the Tc-99m pertechnetate is taken up by the mucin-secreting cells in this gastric tissue.
Key points about the use of the Tc-99m pertechnetate scan for diagnosing Meckel's diverticulum include:
- It has a high sensitivity and specificity in children, making it a valuable diagnostic tool in pediatric cases of unexplained gastrointestinal bleeding, as indicated by the principles outlined in the context of 1.
- The scan's effectiveness can vary in adults, with lower sensitivity compared to pediatric cases.
- Meckel's diverticulum is a remnant of the vitelline duct that failed to completely obliterate during embryonic development, and its persistence can lead to various anomalies, including the most common congenital anomaly of the gastrointestinal tract.
From the Research
Meckel's Diverticulum and Technetium Scan
- Meckel's diverticulum is a congenital gastrointestinal anomaly that can contain ectopic gastric mucosa, leading to complications such as bleeding and perforation 2, 3.
- Technetium-99m pertechnetate scintigraphy is a diagnostic tool used to detect ectopic gastric mucosa in Meckel's diverticulum 2, 3, 4, 5, 6.
Location of the Problem
- The problem associated with Meckel's diverticulum is typically located in the vitelline or yolk sac area, which is a remnant of the embryonic yolk sac 2, 3.
- The exact location of the diverticulum can vary, but it is often found in the ileum, near the junction of the small and large intestines 4.
Diagnostic Accuracy of Technetium Scan
- The technetium-99m pertechnetate scintigraphy has a high diagnostic accuracy for detecting ectopic gastric mucosa in Meckel's diverticulum, with sensitivity and specificity rates ranging from 85% to 95% 2, 3, 5.
- The scan can help identify the location of the diverticulum and guide surgical intervention 2, 3, 4.