Situs inversus, short form of the Latin “situs inversus viscerum”, is a term used to describe the inverted position of chest and abdominal organs. It is called situs inversus totalis when there is a total transposition of abdominal and thoracic viscera (mirror image of internal organs normal positioning).
Situs inversus is usually associated with dextrocardia (true mirror image) with only 3-5% incidence of congenital heart disease, most commonly transposition of the great vessels. Of these patients, 80% have a right-sided aortic arch. Situs inversus with levocardia (which is much rarer: 0.00005%) congenital heart disease is found in 95% of patients 4.
Imaging features on chest radiograph to be evaluated are:
- location of heart apex
- location of aortic arch
- location of stomach bubble / liver
- 1. Maldjian PD, Saric M. Approach to dextrocardia in adults: review. AJR Am J Roentgenol. 2007;188 (6): S39-49. doi:10.2214/AJR.06.1179 - Pubmed citation
- 2. Yokoyama T, Copeland NG, Jenkins NA et-al. Reversal of left-right asymmetry: a situs inversus mutation. Science. 1993;260 (5108): 679-82. Science (link) - Pubmed citation
- 3. Applegate KE, Goske MJ, Pierce G et-al. Situs revisited: imaging of the heterotaxy syndrome. Radiographics. 19 (4): 837-52. Radiographics (full text) - Pubmed citation
- 4. Oski's pediatrics. LWW. ISBN:0781738946. Read it at Google Books - Find it at Amazon