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Axial Mid-Scan Diameter of the Aorta (CT)

Published: August 9, 2026Updated: August 16, 2026

This test measures the width of the aorta at its midpoint using a CT scan, which helps assess whether the aorta is enlarged or at risk for complications like aneurysms.

Quick summary

["A CT scan checks if your aorta is safely sized or if it may need monitoring or treatment."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
96916-2
Short code
CT Avg diam axial mid-scan
Synonyms
CT Avg diam axial mid-scan
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like chest pain, unexplained fatigue, or if you have a family history of aortic conditions. It’s also used to monitor known aortic issues, such as aortic aneurysms or dissections, to prevent serious complications like rupture.

How the Test Works

You’ll lie on a table that slides into a CT machine. A contrast dye may be injected to make blood vessels clearer. The machine takes cross-sectional images of your aorta, and the diameter at the midpoint is measured.

What to Expect Before the Test

No special preparation is needed unless instructed by your doctor. If contrast dye is used, you may be asked to drink plenty of fluids afterward to help your kidneys process it safely.

What the Results Mean

Results are compared to standard measurements for your body size and health. An enlarged aorta (diameter greater than expected) may signal an aneurysm or other vascular concerns that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Aorta Diameter (CT Scan)

Frequently asked questions

What causes an abnormal aorta diameter?
Several factors may contribute to an abnormal aorta diameter, including genetics (e.g., Marfan syndrome), high blood pressure, smoking, aging, or conditions like atherosclerosis. Lifestyle choices like diet, exercise, and avoiding smoking can also influence vascular health.
How often should this test be repeated?
Your doctor will determine how often you need follow-up tests based on your risk factors, symptoms, and test results. Some patients may need monitoring every few months or years, while others may require more frequent checks.
Does this test hurt?
Most people describe the CT scan as a brief, non-painful experience. The injection of contrast dye may cause a temporary, mild reaction like warmth or flushing, but serious reactions are rare. Always inform your doctor about any allergies before the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy