Imaging evaluation of the heterotaxy syndrome

Abstract

Situs ambiguus, or heterotaxy, is a rare syndrome characterized by an abnormal arrangement of the internal organs in the chest and abdomen and is usually associated with congenital heart diseases. Despite its variable presentation, heterotaxy syndrome can be classified into heterotaxy with polysplenia or left isomerism, and heterotaxy with asplenia or right isomerism. The different imaging techniques reveal the characteristic imaging findings that allow an accurate description of each patient's specific anatomy. Evaluation of the position of the following structures relative to midline is crucial: atria, cardiac apex, venous drainage, aorta, stomach, liver and gallbladder, as well as the presence or absence of intestinal malrotation, number of spleens, and presence of tri- or bilobed lungs.