대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Left Isomerism (Interruption of the IVC with Azygos Continuation)

Radiologic Findings

Posteroanterior chest radiograph shows an enlarged azygos vein and a bilateral left-sided configuration of the airway. Lateral chest radiograph shows absent inferior vena cava stripe.

On coronal reformatted image using CT volume data, the main bronchus passes inferior to the ipsilateral main pulmonary artery on each side. Coronal MPR image also shows enlarged azygos vein due to interruption of IVC.

Volume rendering image shows a bilateral left-sided configuration of the airway.

Brief Review

Situs anomalies are rare, complex, and confusing. Situs ambiguous, or heterotaxy, implies a disordered organ arrangement in the chest or abdomen. Classic left isomerism or bilateral left-sidedness implies that patients have bilateral bilobed lungs, bilateral pulmonary atria, a centrally located liver, a stomach in indeterminate position, and multiple spleens. Interruption of the inferior vena cava with azygous or hemiazygous continuation may be suggested from the chest radiograph and is the most consistent finding seen in heterotaxy with polysplenia. In fact, the short intrahepatic segment of the inferior vena cava is present in these cases.

References

1. Applegate KE, Goske MJ, Pierce G, Murphy D. Situs revisited: imaging of the heterotaxy syndrome. Radiographics. 1999;19:837-852

Keywords

Mediastinum, Vascular, Congenital,