Scimitar Syndrome

Author: Santip Srisuwan, M.D.

Fig. 1: Chest radiograph of an asymptomatic young woman shows small right lung volume with cardiomediastinal shift toward the right side, small right hilum and a characteristic scimitar-shaped structure in the right lower lobe (arrow).

Figs 2&3: Contrast-enhanced CT images (maximal intensity projection, and 3D volumetric images) show an anomalous right lower lobe pulmonary vein (arrows) descending vertically, draining the right lower lobe and entering the IVC.

Facts: Scimitar Syndrome

• Also known as venolobar syndrome, hypogenetic lung syndrome
• Associations: congenital heart disease 25% (usually atrial septal defect)
• Symptoms: usually asymptomatic. Patients may have dyspnea if there is a large left to right shunt

Imaging Findings

• Small right lung
• Diminutive right hilum
• Dextroposition of the heart
• Characteristic scimitar vein draining below the diaphragm

Reference:

Hansell DM, et al. Imaging of diseases of the chest. Elsevier Mosby, 4th edition, 2005.

About Guest Author: Dr. Santip Srisuwan is a radiologist at Samitivej Hospital, Bangkok, Thailand.