The median arcuate ligament is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament usually passes superior to the origin of the celiac axis in MALS, compression of the celiac axis, compromising blood flow and causing symptoms
With inspiration, the celiac artery descends in the abdominal cavity, resulting in a more vertical orientation of the celiac artery, which often relieves the compression.
With the patient in the erect position, the celiac artery descends farther in the abdominal cavity, resulting in an even more vertical orientation of the celiac artery and relief of compression by the ligament.
- Evidence of narrowing of celiac artery juxtaostially with fish hook configuration
- Doppler in supine shows aliasing with increased flow velocity noted across the stenotic part of celiac artery
- Doppler study confirms phasic variation of narrowing of celiac artery
- On standing doppler study of celiac artery becomes normal
- acute angulation and indendation on the superior aspect of proximal celiac axis
- focal narrowing has a characteristic hooked appearance
- poststenotic dilatation
- Coronal MIP CT angiogram shows the prominent gastroduodenal artery that feeds the common hepatic artery off the superior mesenteric artery