Meckel's diverticulum other imaging findings: Difference between revisions
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* [[Angiogram|Angiography]] may assist in determining the location and severity of [[bleeding]] in case of a bleeding Meckel's diverticulum. | * [[Angiogram|Angiography]] may assist in determining the location and severity of [[bleeding]] in case of a bleeding Meckel's diverticulum. | ||
* In patients presenting with acute [[Gastrointestinal bleeding|GI bleeding]], [[Superior mesenteric artery|superior mesenteric]] [[Angiogram|angiography]] is effective if [[blood]] loss exceeds 0.5 mL/min(brisk [[bleeding]]).<ref name="urlFundamentals of Pediatric Surgery - Google Books">{{cite web |url=https://books.google.com/books?id=-AAD9WiIZLAC&pg=PA773&lpg=PA773&dq=Mattei,+P.+(2011).+Fundamentals+of+Pediatric+Surgery.+New+York,+NY:+Springer+Science%2BBusiness+Media,+LLC.&source=bl&ots=VWeSV7HsOo&sig=p2LET6NVySpB-ANSdF3G1YmAzw8&hl=en&sa=X&ved=0ahUKEwip4uPoya3YAhUG_IMKHUn8ABIQ6AEIQTAD#v=onepage&q=Mattei%2C%20P.%20(2011).%20Fundamentals%20of%20Pediatric%20Surgery.%20New%20York%2C%20NY%3A%20Springer%20Science%2BBusiness%20Media%2C%20LLC.&f=false |title=Fundamentals of Pediatric Surgery - Google Books |format= |work= |accessdate=}}</ref> | * In patients presenting with acute [[Gastrointestinal bleeding|GI bleeding]], [[Superior mesenteric artery|superior mesenteric]] [[Angiogram|angiography]] is effective if [[blood]] loss exceeds 0.5 mL/min(brisk [[bleeding]]).<ref name="urlFundamentals of Pediatric Surgery - Google Books">{{cite web |url=https://books.google.com/books?id=-AAD9WiIZLAC&pg=PA773&lpg=PA773&dq=Mattei,+P.+(2011).+Fundamentals+of+Pediatric+Surgery.+New+York,+NY:+Springer+Science%2BBusiness+Media,+LLC.&source=bl&ots=VWeSV7HsOo&sig=p2LET6NVySpB-ANSdF3G1YmAzw8&hl=en&sa=X&ved=0ahUKEwip4uPoya3YAhUG_IMKHUn8ABIQ6AEIQTAD#v=onepage&q=Mattei%2C%20P.%20(2011).%20Fundamentals%20of%20Pediatric%20Surgery.%20New%20York%2C%20NY%3A%20Springer%20Science%2BBusiness%20Media%2C%20LLC.&f=false |title=Fundamentals of Pediatric Surgery - Google Books |format= |work= |accessdate=}}</ref> | ||
Conventional contrast mesenteric arteriography has the following indications: | |||
If a source of gastrointestinal bleeding is brisk enough to require transfusion | |||
If the source has not been identified using other imaging modalities | |||
In patients with ongoing haemorrhage, active contrast extravasation may be visible | |||
Detection of an anomalous SMA branch that feeds the diverticulum: | |||
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: | |||
The patient is subjected to ionizing radiation | |||
invasive | |||
The role of Single-photon emission computed tomography (SPECT)/CT fusion imaging as a diagnostic modality is currently under exploration. | |||
==References== | ==References== | ||
Revision as of 22:20, 28 December 2017
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Meckel's diverticulum Microchapters |
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Meckel's diverticulum other imaging findings On the Web |
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American Roentgen Ray Society Images of Meckel's diverticulum other imaging findings |
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Risk calculators and risk factors for Meckel's diverticulum other imaging findings |
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%.
- 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.
- 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
- Meckel's diverticulum is identified as a saccular, blind-ending structure located on the antimesenteric border of the ileum.
- Meckel's diverticulum is usually found in the right lower quadrant and pelvic region.
- The junction of the diverticulum with the ileum may show a mucosal triangular plateau or triradiate fold pattern (represents the site of omphalomesenteric duct attachment to the ileum).
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: If a source of gastrointestinal bleeding is brisk enough to require transfusion If the source has not been identified using other imaging modalities In patients with ongoing haemorrhage, active contrast extravasation may be visible Detection of an anomalous SMA branch that feeds the diverticulum: 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: The patient is subjected to ionizing radiation invasive The role of Single-photon emission computed tomography (SPECT)/CT fusion imaging as a diagnostic modality is currently under exploration.
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.