Meckel's diverticulum other imaging findings
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sudarshana Datta, MD [2]
Overview
A technetium-99m (99mTc) pertechnetate scan is the investigation of choice for the diagnosis of Meckel's diverticulum. This scan detects gastric mucosa; since approximately 50% of symptomatic Meckel's diverticula have ectopic gastric (stomach) cells contained within them. A Meckel's diverticulum containing gastric mucosa manifests as a small rounded area of increased activity in the right lower quadrant, while normal activity simultaneously appears in the stomach.
Other Imaging Findings
Technetium-99m pertechnetate radioisotope scanning
- September 2014: Guidelines for the Scintigraphy for Meckel’s diverticulum were laid down by:[1]
- Society of Nuclear Medicine and Molecular Imaging (SNMMI)
- European Association for Nuclear Medicine (EANM)
- Technetium-99m pertechnetate scanning helps in the detection of a symptomatic bleeding Meckel’s diverticulum.
- It is preferred as the investigation of choice for the diagnosis of Meckel's diverticula in children due to the following features:[2]
- High accuracy
- Noninvasive nature
- 95% specificity
- 85% sensitivity
- Approximately 50% of symptomatic Meckel's diverticula have ectopic gastric or pancreatic cells contained within them[3]
- Technetium-99m pertechnetate scanning is not preferred in adults as false negative rates are high with specificity of 9% and sensitivity of 62%.
- Indications of Meckel's scan:[4][5]
- False-positives are seen in the following conditions:
- Intussusception
- Volvulus
- Obstruction of the small intestine
- Acute appendicitis
- Carcinoid of the appendix
- Carcinoma of the cecum
- On intravenous administration, the Technetium-99m pertechnate radioisotope is taken up by the gastric mucosa.[6]
- In order to obtain a positive result, atleast 1.8 cm2 of ectopic gastric mucosa in Meckel's diverticulum is required.
- A Meckel's diverticulum containing gastric mucosa manifests as a small rounded area of increased activity in the right lower quadrant.
- Normal activity simultaneously appears in the stomach.
- Technetium-99m pertechnetate scanning requires 30 images, taken at 1-minute intervals to demonstrate terminal ileum activity.
- The use of Pentagastrin in Technetium-99m pertechnetate scanning has a synergistic effect:
- Role of Pentagastrin:
- Histamine-2 (H2) receptor blocker
- Enhances radioisotope uptake by the cells:
- Promotes isotope retention
- Blocks intraluminal release of isotope
- Minimizes false negative results
- Agents promoting retention of 99m technetium pertechnetate:[7]
- Aluminum hydroxide
- Ranitidine, Cimetidine
Angiography
- Angiography may assist in determining the location and severity of bleeding in case of a bleeding Meckel's diverticulum.
- In patients presenting with acute GI bleeding, superior mesenteric angiography is effective if blood loss exceeds 0.5 mL/min(brisk bleeding).[2]
- Conventional contrast mesenteric arteriography has the following indications:[8][9]
- If a source of gastrointestinal bleeding is brisk and may require transfusion
- If the source has not been identified using other imaging modalities
- In patients with ongoing hemorrhage, active contrast extravasation may be visible
- Detection of an anomalous branch of the superior mesenteric artery that feeds the diverticulum. This anomalous branch usually has the following features:
- Non branching
- Long
- Terminates in irregular, small branches after traversing the mesentery
- High-resolution CT angiography is preferred in patients when bleeding is less brisk (as little as 0.3 mL/minute).
- CT angiography may help detect active signs of bleeding diverticulum, that may be undetectable with other modalities such as
- Tagged red blood cell scan
- Colonoscopy
- Conventional arteriography
- Disadvantage:
- Patient is subject to ionizing radiation
- Invasive
Single-photon emission computed tomography (SPECT)/CT fusion imaging
- The role of Single-photon emission computed tomography (SPECT)/CT fusion imaging as a diagnostic modality is currently under exploration.[10]
References
- ↑ Spottswood SE, Pfluger T, Bartold SP, Brandon D, Burchell N, Delbeke D, Fink-Bennett DM, Hodges PK, Jolles PR, Lassmann M, Maurer AH, Seabold JE, Stabin MG, Treves ST, Vlajkovic M (2014). "SNMMI and EANM practice guideline for meckel diverticulum scintigraphy 2.0". J Nucl Med Technol. 42 (3): 163–9. doi:10.2967/jnmt.113.136242. PMID 24948825.
- ↑ 2.0 2.1 "Fundamentals of Pediatric Surgery - Google Books".
- ↑ Martin JP, Connor PD, Charles K (2000). "Meckel's diverticulum". Am Fam Physician. 61 (4): 1037–42, 1044. PMID 10706156.
- ↑ Lin S, Suhocki PV, Ludwig KA, Shetzline MA (2002). "Gastrointestinal bleeding in adult patients with Meckel's diverticulum: the role of technetium 99m pertechnetate scan". South. Med. J. 95 (11): 1338–41. PMID 12540005.
- ↑ Sinha CK, Pallewatte A, Easty M, De Coppi P, Pierro A, Misra D, Biassoni L (2013). "Meckel's scan in children: a review of 183 cases referred to two paediatric surgery specialist centres over 18 years". Pediatr. Surg. Int. 29 (5): 511–7. doi:10.1007/s00383-013-3270-3. PMID 23417523.
- ↑ Rerksuppaphol S, Hutson JM, Oliver MR (2004). "Ranitidine-enhanced 99mtechnetium pertechnetate imaging in children improves the sensitivity of identifying heterotopic gastric mucosa in Meckel's diverticulum". Pediatr. Surg. Int. 20 (5): 323–5. doi:10.1007/s00383-004-1189-4. PMID 15241619.
- ↑ Petrokubi RJ, Baum S, Rohrer GV (1978). "Cimetidine administration resulting in improved pertechnetate imaging of Meckel's diverticulum". Clin Nucl Med. 3 (10): 385–8. PMID 729309.
- ↑ Routh WD, Lawdahl RB, Lund E, Garcia JH, Keller FS (1990). "Meckel's diverticula: angiographic diagnosis in patients with non-acute hemorrhage and negative scintigraphy". Pediatr Radiol. 20 (3): 152–6. PMID 2352792.
- ↑ García-Blázquez V, Vicente-Bártulos A, Olavarria-Delgado A, Plana MN, van der Winden D, Zamora J (2013). "Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis". Eur Radiol. 23 (5): 1181–90. doi:10.1007/s00330-012-2721-x. PMID 23192375.
- ↑ Dillman JR, Wong KK, Brown RK, Frey KA, Strouse PJ (2009). "Utility of SPECT/CT with Meckel's scintigraphy". Ann Nucl Med. 23 (9): 813–5. doi:10.1007/s12149-009-0301-1. PMID 19784878.