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Magnetic Resonance Venography (MRV), With or Without Contrast

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

An MRI scan of the veins used to evaluate blood clots and other venous problems. Your scan may include intravenous contrast.

Quick summary

["MRI venography creates detailed images of the veins and may use IV contrast to help identify clots or other abnormalities."]

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

Key facts at a glance

LOINC
36545-2
Short code
MR IVC WO contr
Synonyms
MR IVC WO contr
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
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?

Magnetic resonance venography, or MRV, is an MRI-based imaging test that produces detailed pictures of the veins. It is often used to examine the veins in the head and neck but may be performed elsewhere in the body.

Why might I need this test?

Your clinician may order this test to evaluate a suspected blood clot, swelling related to impaired venous drainage, persistent headaches, or other symptoms that may involve the veins. It may also be used to monitor the location or extent of a known clot.

How is the test performed?

You will lie on a table inside an MRI scanner while the machine creates images of the veins. If contrast is included, it is usually given through a vein in your arm, and images may be taken before and after the injection.

How do I prepare for the test?

Fasting is generally not required, but follow the instructions provided by the imaging center. Tell the care team about metal implants, pregnancy, claustrophobia, kidney disease, or any previous reaction to MRI contrast, and remove jewelry and other metal objects before the scan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An abnormal result may show a blockage, clot, narrowing, or unusual blood flow within a vein. These findings can help explain symptoms such as swelling, pain, headache, or changes in vision, but they must be interpreted with your symptoms, medical history, and other imaging tests.

Short name

MRI venography

Frequently asked questions

Does MRI venography always use contrast?
No. Although it may be ordered as a with-or-without-contrast study, the imaging center will use the protocol appropriate for the area being examined and your clinical situation. Ask the ordering clinician whether contrast is expected.
Is the MRI scan painful?
Most people do not feel pain during the scan, although the narrow scanner, loud noises, and need to remain still may be uncomfortable. An IV injection for contrast may cause a brief sensation and rarely causes mild bruising.
Can I have this test if I am pregnant or have metal in my body?
Tell the care team before the test if you are pregnant, could be pregnant, or have a pacemaker, implant, or other metal device. These circumstances require safety review and may affect whether the test or contrast can be 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