Intramural bowel gas
Updates to Article Attributes
Intramural bowel gas, also known as pneumatosis intestinalis, refers to the clinical or radiological finding of gas within the wall of the bowel.
Terminology
There are different terminologies in the medical literature, such as pneumatosis intestinalis, pneumatosis coli, and pneumatosis cystoides intestinalis. Pneumatosis coli is used when only the colic wall is involved and is generally an incidental finding in asymptomatic patients. Pneumatosis cystoides intestinalis is descriptive for multiple gaseous cysts along the bowel wall.
Pathology
Intramural gas can be seen in intestinal ischaemia and eventually bowel infarction. This is the most concerning aetiology for intramural gas.
Gas in the bowel wall in the neonatal period, whatever its shape, is diagnostic of necrotising enterocolitis.
Asymptomatic pneumatosis intestinalis may result from a variety of interrelated contributing factors including:
- mucosal integrity
- intraluminal pressure
- bacterial flora
- intraluminal gas
Benign pneumatosis can be caused by a variety of reasons such as pulmonary disease, systemic disease (scleroderma, lupus, AIDS), intestinal inflammation, iatrogenic/procedures, medications, and organ transplation4.
Life-threatening pneumatosis can be caused by intestinal ischemia, obstruction, enteritis/colitis, toxic caustic ingestion, toxic megacolon, organ transplantation, and collagen vascular disease4.
Radiographic features
Gas tracks along the bowel wall, appearing as either linear, which are usually submucosal, or rounded cystic "bubbly" collections, which are usually subserosal 1. Where they join, they may outline the circumferenial margin of the bowel, creating rings.
Gas in the bowel wall is most easily identified with CT and plain radiography, but ultrasound and MRI can be usefully in paediatric patients where there is a desire to avoid radiation.
OtherA common diagnostic dilemma is differentiate benign pneumatosis from clinically worrisome causes 4,5. The following are imaging findings help differentiate sinister causes from benign causes, such as 4
dilated bowel- soft tissue bowel wall thickening
- free intraperitoneal fluid
- lesser extent of pneumatosis (more extensive pneumatosis is more commonly benign)
- periintestinal soft-tissue stranding
- abnormal bowel wall enhancement
portal venous gas-
pneumoperitoneumandpneumoretroperitoneum-
can be seen with both idiopathic and ischemic pneumatosis3
-
- atherosclerosis and vascular occlusion
ascites
The presence of pneumomediastinum favours a benign cause 1.Pneumoperitoneum and pneumoretroperitoneum can be seen with both idiopathic and ischemic pneumatosis 3
Differential diagnosis
- bowel ischaemia and infarction
- infection
- inflammatory bowel disease
- medication-induced
- chemotherapy
- steroid use
- autoimmune disease and immunosuppression
- connective tissue disorders
- primary pneumatosis
- pulmonary disease
- idiopathic
- iatrogenic
- post endoscopy / colonoscopy
- post operative
- post enteric tube
- CT colonography
- pseudopneumatosis (mimics) include:
- gas trapped between bowel wall and luminal contents
- gas trapped by opposing mucosal folds
- gas bubbles adherent to bowel wall
Practical points
From a clinical perspective, it is essential not to confuse the incidental imaging finding of asymptomatic pneumatosis with symptomatic colonic perforation because the treatment is significantly different 2.
See also
-</ul><h4>Radiographic features</h4><p>Gas tracks along the bowel wall, appearing as either linear, which are usually submucosal, or rounded cystic "bubbly" collections, which are usually subserosal <sup>1</sup>. Where they join, they may outline the circumferenial margin of the bowel, creating rings.</p><p>Gas in the bowel wall is most easily identified with CT and plain radiography, but ultrasound and MRI can be usefully in paediatric patients where there is a desire to avoid radiation.</p><p>Other imaging findings help differentiate sinister causes from benign causes, such as <sup>4</sup>:</p><ul>-<li>dilated bowel</li>-<li>bowel wall thickening</li>- +</ul><p><strong>Benign pneumatosis </strong>can be caused by a variety of reasons such as pulmonary disease, systemic disease (scleroderma, lupus, AIDS), intestinal inflammation, iatrogenic/procedures, medications, and organ transplation<sup>4</sup>.</p><p><strong>Life-threatening pneumatosis</strong> can be caused by intestinal ischemia, obstruction, enteritis/colitis, toxic caustic ingestion, toxic megacolon, organ transplantation, and collagen vascular disease<sup>4</sup>.</p><h4>Radiographic features</h4><p>Gas tracks along the bowel wall, appearing as either linear, which are usually submucosal, or rounded cystic "bubbly" collections, which are usually subserosal <sup>1</sup>. Where they join, they may outline the circumferenial margin of the bowel, creating rings.</p><p>Gas in the bowel wall is most easily identified with CT and plain radiography, but ultrasound and MRI can be usefully in paediatric patients where there is a desire to avoid radiation.</p><p>A common diagnostic dilemma is differentiate benign pneumatosis from clinically worrisome causes <sup>4,5</sup>. <em>The following are imaging features of clinically worrisome pneumatosis:</em></p><ul>
- +<li>soft tissue bowel wall thickening</li>
- +<li>free intraperitoneal fluid</li>
- +<li>lesser extent of pneumatosis (more extensive pneumatosis is more commonly benign)</li>
- +<li>periintestinal soft-tissue stranding</li>
-<li><a href="/articles/portal-venous-gas">portal venous gas</a></li>-<li>-<a href="/articles/pneumoperitoneum">pneumoperitoneum</a> and <a href="/articles/pneumoretroperitoneum">pneumoretroperitoneum</a><ul><li>can be seen with both idiopathic and ischemic pneumatosis <sup>3</sup>-</li></ul>-</li>-<li><a href="/articles/ascites">ascites</a></li>-</ul><p>The presence of <a href="/articles/pneumomediastinum">pneumomediastinum</a> favours a benign cause <sup>1</sup>.</p><h4>Differential diagnosis</h4><ul>- +</ul><p>The presence of <a href="/articles/pneumomediastinum">pneumomediastinum</a> favours a benign cause <sup>1</sup>. <a href="/articles/pneumoperitoneum">Pneumoperitoneum</a> and <a href="/articles/pneumoretroperitoneum">pneumoretroperitoneum</a> can be seen with both idiopathic and ischemic pneumatosis <sup>3</sup></p><h4>Differential diagnosis</h4><ul>
References changed:
- 5. Olson DE, Kim YW, Ying J, Donnelly LF. CT predictors for differentiating benign and clinically worrisome pneumatosis intestinalis in children beyond the neonatal period. (2009) Radiology. 253 (2): 513-9. <a href="https://doi.org/10.1148/radiol.2532090168">doi:10.1148/radiol.2532090168</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19710000">Pubmed</a> <span class="ref_v4"></span>
Image 8 CT (lung window) ( create )
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