After the arterial switch the pulmonary arteries drape over the aorta (Lecompte); follow-up looks for branch pulmonary artery stenosis, neo-aortic root dilatation and regurgitation, and coronary ostial stenosis.
Orient first
- D-TGA: aorta from the RV, pulmonary artery from the LV; corrected by arterial switch with coronary transfer.
- Older patients may have had an atrial switch (Mustard/Senning): systemic RV and baffle problems.
- Congenitally corrected TGA (L-TGA) has a systemic RV without surgery.
Acquire the study
- Cine short-axis and long axes, 3D contrast-enhanced MRA, phase-contrast flow, LGE.
The manoeuvre
- 3D MRA: branch pulmonary artery calibre in mm; stenosis as they drape over the aorta.
- Phase-contrast: differential flow to right and left lungs in %.
- Neo-aortic root diameter in mm at the sinuses; neo-aortic regurgitant fraction.
- LV function and LGE (perfusion defects from coronary problems).
What confirms it
- Anatomy and function documented against the operative history.
What licenses you to exclude it
- Normal branch PAs, neo-aorta and coronaries exclude the main late complications.
The classic misread
- Missing an atrial-switch baffle leak because the operation history was not known.