Skip to content

CT Angiography of Lower-Extremity Vessels With or Without Intravenous Contrast

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

A CT scan that evaluates blood flow through the arteries of the legs, sometimes before and after intravenous contrast is given.

Quick summary

["This test uses CT imaging to help identify narrowing, blockage, or other problems in the arteries supplying the legs."]

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

Key facts at a glance

LOINC
46308-3
Short code
CTA LE ves-L WO+W contr IV
Synonyms
CTA LE ves-L WO+W contr IV
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct-angio
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

What is this test?

Lower-extremity CT angiography is an imaging test that uses X-rays and a computer to show the blood vessels that supply the legs. Intravenous contrast may be used to improve the visibility of the arteries.

Why might I need this test?

This test may be recommended for leg pain, cramping, numbness, cold feet, slow-healing sores, or swelling. It can help evaluate suspected peripheral artery disease and may also be used for surgical planning or when there is concern about a blood clot.

How is the test performed?

You lie on a CT scanner table while the scanner takes pictures around the legs. If contrast is used, it is given through a vein in your arm, and images may be obtained before and after the injection.

How do I prepare for the test?

Fasting is usually not required, but the imaging center may give specific instructions. Tell your care team about any contrast allergy, kidney disease, pregnancy, or medicines such as metformin so they can determine whether special precautions are needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lower-extremity CT angiography

Frequently asked questions

Does this test use contrast?
The protocol may include intravenous contrast, which contains iodine and helps outline the blood vessels. Whether contrast is required depends on the specific scan ordered.
Is CT angiography the same as a standard leg CT?
Not always. CT angiography is specifically designed to evaluate the arteries and blood flow, often using timing and contrast techniques that differ from a routine CT scan.
Will I need to have the scan repeated with and without contrast?
Some protocols obtain images before and after contrast. Your imaging center will provide the exact instructions for the scan being performed.
  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