Sonographic findings in mid-aortic syndrome

Abstract

Mid-aortic syndrome (MAS) is an uncommon condition characterised by narrowing of the distal descending thoracic or abdominal aorta. While CT, MR and conventional angiography findings in MAS are well described, there have been very few cases which clearly document the sonographic features of this condition. This case report demonstrates the utility of ultrasound in the investigation of MAS and summarises the current literature surrounding the condition.

Figure 1.

B-mode ultrasound image of the suprarenal abdominal aorta in longitudinal orientation demonstrates irregular narrowing of the aorta with a diameter of 11 mm (where a normal diameter is 21–25 mm).

Figure 2.

Colour and pulse wave Doppler ultrasound demonstrates turbulent flow and an elevated peak systolic velocity within the narrowed suprarenal abdominal aorta.

Figure 3.

Pulse wave Doppler ultrasound demonstrates an elevated peak systolic velocity within the narrowed suprarenal abdominal aorta of 360 cm/s (where a normal velocity is up to 150 cm/s).

Figure 4.

Pulse wave Doppler ultrasound demonstrates a relative reduction in abdominal aorta peak systolic velocity with a tardus parvus waveform at the level of the left renal artery ostium.

Figure 5.

Coronal CT angiogram of the distal descending thoracic aorta and abdominal aorta demonstrates progressive narrowing (indicated in red) and an increase in diameter distally (indicated in green).

Figure 6.

Sagittal CT angiogram demonstrates progressive narrowing of the distal descending thoracic and abdominal aorta to the level of the renal arteries (10.8 mm) distal to which it increases in calibre (14.5 mm). There is atresia of the proximal coeliac axis (indicated by the red arrow) and superior mesenteric artery (the origin not visible in this image), and an enlarged inferior mesenteric artery (indicated by the green arrow). Coeliac axis and SMA branches originate from a 22 mm aneurysmal dilatation of the proximal SMA (indicated by the yellow arrow) where there is an anastomosis with the IMA via a dilated marginal artery of Drummond.