How MALS is diagnosed: tests, what they show and their limits

There is no single test that confirms median arcuate ligament syndrome (MALS), and there are no diagnostic criteria that all experts agree on [1][9]. Doctors combine typical symptoms, imaging that shows the celiac artery being compressed, and the exclusion of more common causes of the pain [1][2].

Step 1: ruling out more common causes

Because pain after eating, nausea and weight loss have many possible causes, MALS is usually considered only after other conditions have been checked [2]. This usually means a series of tests chosen by your doctors to check the more common causes first. Young patients and parents describe this stage as one of many tests and of feeling misunderstood [7]. Our page on conditions doctors rule out goes through the most common ones.

Duplex ultrasound

A duplex (Doppler) ultrasound is a painless scan that measures the speed of blood in the celiac artery. Where the artery is squeezed, the blood flows faster. In a study comparing people with and without MALS, the peak speed in the celiac artery was higher in people with MALS both when they held their breath after breathing in and after breathing out, and highest after breathing out [4].

The same study notes that published cut-off values are inconsistent, so a single number should not be read in isolation; the authors suggest combining the speeds measured in both breathing positions [4].

CT angiography and MR angiography

CT angiography (CTA) and MR angiography (MRA) are scans with contrast that show the blood vessels in 3D. They can show where the celiac artery is narrowed and how much [2]. Angiography that compares breathing in and breathing out has been suggested as a useful way to show compression that changes with breathing [8].

There is an important limit. In a study of CT scans from 321 healthy kidney donors, 3.4% had a narrowing of more than 50% at the start of the celiac artery, and the authors showed that the celiac artery normally leaves the aorta downward and then turns upward. This "hook" shape alone should therefore not be read as compression [3].

Tests used to predict who may benefit

Because a narrowed artery is common and the symptoms are not specific, some centers add tests that try to show whether the narrowing actually causes the symptoms:

• Gastric exercise tonometry. This test measures signs of reduced blood supply in the stomach during exercise. In one prospective study of 43 people with significant compression, 30 had abnormal results; of those treated, 83% were free of symptoms after a median of 39 months [5].
• Celiac plexus (ganglion) block. An injection that temporarily numbs the nerves around the celiac artery. Short-term relief after the block, together with exercise tonometry, has been described as useful in predicting a better result after treatment [6].

Putting the results together

Most reviews describe the diagnosis as a combination of three things [1][2][10]:

1. typical symptoms, such as pain after eating or exercise and weight loss;
2. imaging that shows significant compression of the celiac artery, ideally changing with breathing;
3. no better explanation for the symptoms after a careful workup.

Treatment options are covered on our pages about MALS surgery and treatment without surgery.

Questions to ask your doctor

• Was my celiac artery measured when breathing in and when breathing out? What were the speeds?
• Did the CT or MR scan show compression, or only the normal "hook" shape?
• Which other causes of my symptoms have been ruled out, and which have not?
• Would a celiac plexus block or another test help predict whether treatment will help me?
• How many people with suspected MALS does your team evaluate each year?

Sources

1. Goodall R, Langridge B, Onida S, et al. Median arcuate ligament syndrome. J Vasc Surg. 2020;71(6):2170-2176. PubMed 31882314
2. Kim EN, Lamb K, Relles D, et al. Median Arcuate Ligament Syndrome-Review of This Rare Disease. JAMA Surg. 2016;151(5):471-7. PubMed 26934394
3. Petnys A, Puech-Leao P, Zerati AE, et al. Prevalence of signs of celiac axis compression by the median arcuate ligament on computed tomography angiography in asymptomatic patients. J Vasc Surg. 2018;68(6):1782-1787. PubMed 29914831
4. Romer C, Fischer T, Haase O, et al. Assessment of celiac artery compression using color-coded duplex sonography. Clin Hemorheol Microcirc. 2020;76(3):413-423. PubMed 32675404
5. Mensink PB, van Petersen AS, Kolkman JJ, et al. Gastric exercise tonometry: the key investigation in patients with suspected celiac artery compression syndrome. J Vasc Surg. 2006;44(2):277-81. PubMed 16890853
6. Gloviczki P, Duncan AA. Treatment of celiac artery compression syndrome: does it really exist? Perspect Vasc Surg Endovasc Ther. 2007;19(3):259-63. PubMed 17911551
7. Stiles-Shields C, Osos S, Sunnquist ML, et al. Patient-Reported Experiences With Median Arcuate Ligament Syndrome: Resilience and Resources Required. Clin Pract Pediatr Psychol. 2022;10(1):44-53. PubMed 37577147
8. Giakoustidis A, Moschonas S, Christodoulidis G, et al. Median arcuate ligament syndrome often poses a diagnostic challenge: A literature review with a scope of our own experience. World J Gastrointest Surg. 2023;15(6):1048-1055. PubMed 37405099
9. Lal V, Guazzo L. Median arcuate ligament syndrome: When to consider the diagnosis and management options. Aust J Gen Pract. 2024;53(12 Suppl):S28-S32. PubMed 39693747
10. Gotti KE, Velikoudi MD, Kourgiali CG, et al. Current Evidence on the Treatment of Median Arcuate Ligament Syndrome: A Comprehensive Review. Cureus. 2026;18(7):e113409. PubMed 42643959

MALS Compass is an independent educational website, not a medical provider, and is not affiliated with any hospital, clinic or university. This page is educational information and does not replace advice from your own doctor. For any question about your health, please contact your doctor or an official healthcare institution.