Scimitar Syndrome

Case #002
Date: 12/6/2009

History

18 year old female with a history of a cardiac murmur at birth.

Images


Scimitar_001.jpg
Scimitar_002.jpg
Scimitar_CT_Snapshot.jpg
The PA radiograph demonstrates dextrocardia with an anomalous pulmonary vessel coursing toward the diaphragm, which is also seen on the lateral projection. The single coronal CT image nicely demonstrates this anomalous vessel.

Please click on the image below to view the entire coronal series.

scimitar_dextrocardia.jpg

The coronal reconstruction demonstrates that the patient's dextrocardia is related to mediastinal shift secondary to the hypoplastic right lung. The small right pulmonary artery is also highlighted in these images.


Diagnosis

Scimitar Syndrome.

Explanation

Scimitar Syndrome (Hypogenetic Lung Syndrome, Pulmonary Venolobar Syndrome) is a type of pulmonary hypoplasia that is characterized by anomalous venous drainage of most or all of the abnormal lung to the IVC above or just below the level in the diaphragm. The syndrome was given its name because a single anomalous vein can be seen as a vertically oriented curvilinear density in the right middle lung, resembling a Turkish scimitar. This classic appearance only occurs in about one third of cases; the majority of cases have multiple smaller draining veins that are not clearly visualized on a single radiograph.

Scimitar syndrome almost always affects the right lung, and has the following characteristics:
- Hypoplasia of the the lung with abnormal segmental or lobar anatomy.
- Hypoplasia of the ipsilateral pulmonary artery.
- Anomalous pulmonary venous return.
- Anomalous systemic arterial supply to the lower lobe.
- Mediastinal shift towards the affected lung.
- Congenital heart disease in 25% of patients (ASD is most common)

Although these features typically coexist, there is considerable variation in the degree of expression.

Most patients are symtomatic, and typically present before 30 years of age with recurrent infection, symptoms related to the left to right shunt, or the associated cardiac abnormalities. Surgical treatment involves implanting the anomalous pulmonary vein into the left atrium.


Resources

Webb, WR et al. Fundamentals of Body CT. Elsevier Health Sciences, 2006
Webb, WR and Higgans, CB. Thoracic Imaging: Pulmonary and Cardiovascular Radiology. Lippincott Williams & Wilkins, 2005.
Brant, WE and Helms, CA. Fundamentals of Diagnostic Radiology. Third Edition, 2007.