Tuesday, 9 June 2015

xrayoftheweek 23: what's the story behind this xray?

This week's #xrayoftheweek is the type that is loved in radiology exams - there are a number of findings which add up to a story, and it can be worked out all from careful analysis of the x-ray.

Can you work it out?

The three key signs here are:
1. Large well-defined opacity with smooth contours adjacent to left hilum, with no loss of silhouette with the left heart border. 
2. Sternotomy wires which look rather small for an adult sternotomy.
3. Right sided aortic arch.

This is a case of Tetralogy of Fallot with surgical repair in childhood, with massive pulmonary arterial dilatation. A right sided aortic arch is found in 25% of cases. The small sternotomy wires indicate that the surgery was done when the patient was a child. The pulmonary arterial dilatation is secondary to a combination of pulmonary stenosis and regurgitation which can occur following pulmonary valvular surgery (to correct the right ventricular outflow tract obstruction that is a key feature of Tetralogy of Fallot). 

This axial CT image shows the enlarged pulmonary arteries and the right sided aorta.

#FOAMed #FOAMRad #meded