Diaphragmatic eventration refers to an abnormal contour of the diaphragmatic dome. It typically affects only a segment of the hemidiaphragm, compared to paralysis/weakness where the entire hemidiaphragm is typically affected.
Diaphragmatic eventration is congenital in nature and due to incomplete muscularisation of the diaphragm with a thin membranous sheet replacing normal diaphragmatic muscle. Over time this region stretches and on inspiration does not contract normally.
Frequently eventration is seen in the anteromedial portion of the right hemidiaphragm.
Elevation of the affected portion of the diaphragm is usually seen as a smooth hump, while the remainder of the hemidiaphragm contour is normal. The frontal X-ray may show a 'double' diaphragmatic contour, which is easily confirmed on the lateral projection.
- may be a sharp border between eventrated portion and the remainder of the hemidiaphragm 4
Possible considerations on plain film include:
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- 2. Oh A, Gulati G, Sherman ML et-al. Bilateral eventration of the diaphragm with perforated gastric volvulus in an adolescent. J. Pediatr. Surg. 2000;35 (12): 1824-6. doi:10.1053/jpsu.2000.19271 - Pubmed citation
- 3. Mantoo SK, Mak K. Congenital diaphragmatic eventration in an adult: a diagnostic dilemma. Singapore Med J. 2007;48 (5): e136-7. Singapore Med J (link) - Pubmed citation
- 4. Nason LK, Walker CM, McNeeley MF et-al. Imaging of the diaphragm: anatomy and function. Radiographics. 2012;32 (2): E51-70. doi:10.1148/rg.322115127 - Pubmed citation