Meckel's diverticulum other imaging findings: Difference between revisions
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==Overview== | ==Overview== | ||
A [[technetium-99m]] (99mTc) pertechnetate scan is the investigation of choice | A [[technetium-99m]] [[Technetium-99|(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 diverticulum|Meckel's diverticula]] have [[Ectopia|ectopic]] [[Stomach|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== | ==Other Imaging Findings== | ||
'''Technetium-99m pertechnetate radioisotope scanning''' | '''Technetium-99m pertechnetate radioisotope scanning''' | ||
* September 2014: Guidelines for the Scintigraphy for Meckel’s diverticulum were laid down by: | * September 2014: Guidelines for the [[Nuclear medicine|Scintigraphy]] for Meckel’s diverticulum were laid down by: | ||
** Society of Nuclear Medicine and Molecular Imaging (SNMMI) | ** Society of Nuclear Medicine and Molecular Imaging (SNMMI) | ||
** European Association for Nuclear Medicine (EANM) | ** European Association for Nuclear Medicine (EANM) | ||
* Technetium-99m pertechnetate scanning helps in the detection of a symptomatic bleeding Meckel’s diverticulum. | * [[Technetium-99m|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: | * It is preferred as the investigation of choice for the diagnosis of Meckel's diverticula in children due to the following features: | ||
** High accuracy | ** High accuracy | ||
** Noninvasive nature | ** [[Non-invasive (medical)|Noninvasive]] nature | ||
** 95% specificity | ** 95% [[Specificity (tests)|specificity]] | ||
** 85% sensitivity | ** 85% [[Sensitivity (tests)|sensitivity]] | ||
** Approximately 50% of symptomatic Meckel's diverticula have ectopic gastric or pancreatic cells contained within them | ** Approximately 50% of symptomatic Meckel's diverticula have [[Ectopia|ectopic]] [[Stomach|gastric]] or [[Pancreas|pancreatic cells]] contained within them | ||
* Technetium-99m pertechnetate scanning is not preferred in adults as false negative rates are high with specificity of 9% and sensitivity of 62%. | * [[Technetium-99m|Technetium-99m pertechnetate scanning]] is not preferred in adults as [[Type I and type II errors|false negative]] rates are high with [[Specificity (tests)|specificity]] of 9% and [[Sensitivity (tests)|sensitivity]] of 62%. | ||
* False-positives are seen in the following conditions: | * [[Type I and type II errors|False-positives]] are seen in the following conditions: | ||
** Intussusception | ** [[Intussusception]] | ||
** Volvulus | ** [[Volvulus]] | ||
** Obstruction of the small intestine | ** [[Obstruction]] of the [[small intestine]] | ||
** Acute appendicitis | ** [[Appendicitis|Acute appendicitis]] | ||
** Carcinoid of the appendix | ** [[Carcinoid Tumor|Carcinoid]] of the [[Vermiform appendix|appendix]] | ||
** Carcinoma of the | ** [[Carcinoma]] of the [[cecum]] | ||
* On intravenous administration, the Technetium-99m pertechnate radioisotope is taken up by the gastric mucosa. | * On [[Intravenous therapy|intravenous]] administration, the [[Technetium-99m|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 diverticulum is required. | * In order to obtain a positive result, atleast 1.8 cm2 of [[Ectopia|ectopic]] [[gastric mucosa]] in Meckel's diverticulum is required. | ||
* Technetium-99m pertechnetate scanning requires 30 images, taken at 1-minute intervals to demonstrate terminal | * A Meckel's diverticulum containing [[gastric mucosa]] manifests as a small rounded area of increased activity in the right lower quadrant. | ||
* The use of Pentagastrin in Technetium-99m pertechnetate scanning has a synergistic effect: | * Normal activity simultaneously appears in the [[stomach]]. | ||
* Role of Pentagastrin: | * [[Technetium-99m|Technetium-99m pertechnetate scanning]] requires 30 images, taken at 1-minute intervals to demonstrate [[terminal ileum]] activity. | ||
** Histamine-2 (H2) receptor blocker | * The use of [[Pentagastrin]] in [[Technetium-99m|Technetium-99m pertechnetate scanning]] has a synergistic effect: | ||
** Enhances radioisotope uptake by the cells: | * Role of [[Pentagastrin]]: | ||
*** Promotes isotope retention | ** [[Histamine receptor|Histamine-2 (H2) receptor blocker]] | ||
*** Blocks intraluminal release of isotope | ** Enhances radioisotope uptake by the [[Cell (biology)|cells]]: | ||
*** Minimizes false negative results | *** Promotes [[isotope]] retention | ||
* Meckel's diverticulum is identified as a saccular, blind-ending structure located on the antimesenteric border of the ileum. | *** Blocks intraluminal release of [[isotope]] | ||
* Meckel's diverticulum is usually found in the right lower quadrant and pelvic region. | *** Minimizes [[Type I and type II errors|false negative]] results | ||
* 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 | * 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 [[Pelvis|pelvic region]]. | |||
* The junction of the diverticulum with the [[ileum]] may show a mucosal triangular plateau or triradiate fold pattern (represents the site of [[Vitelline duct|omphalomesenteric duct]] attachment to the [[ileum]]). | |||
==== Angiography ==== | |||
* [[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]]). | |||
==References== | ==References== | ||
Revision as of 20:24, 28 December 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
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:
- 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:
- High accuracy
- Noninvasive nature
- 95% specificity
- 85% sensitivity
- Approximately 50% of symptomatic Meckel's diverticula have ectopic gastric or pancreatic cells contained within them
- 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).