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MRI of the Sacrum and Sacroiliac Joints with Intravenous Contrast

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

An MRI uses magnetic fields and intravenous contrast to create detailed images of the lower spine, sacrum, and sacroiliac joints.

Quick summary

["This imaging test can help identify causes of low back or pelvic pain affecting the sacrum or sacroiliac joints."]

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

Key facts at a glance

LOINC
91594-2
Short code
MR Sacrum and SIJ W contr IV
Synonyms
MR Sacrum and SIJ 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
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?

This is a magnetic resonance imaging (MRI) examination of the sacrum, the triangular bone at the base of the spine, and the sacroiliac joints, which connect the spine to the pelvis. Intravenous contrast may be used to make certain tissues and abnormalities easier to see.

Why might I need this test?

The test may be ordered to evaluate persistent lower back, pelvic, buttock, or leg pain. It can help assess problems involving the sacrum or sacroiliac joints, including inflammation, injury, infection, arthritis, or certain bone abnormalities.

How is the test performed?

You will lie on a table inside the MRI scanner while images are taken. If contrast is required, it is usually injected into a vein in your arm before or during the examination. The scan may take 30 to 60 minutes, although timing varies.

How do I prepare for the test?

Follow the instructions provided by the imaging center, especially if contrast will be used. Tell the care team about any prior contrast reaction, kidney disease, implanted medical devices, metal fragments, pregnancy, or anxiety about enclosed spaces. Remove jewelry and other metal objects before the scan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

MRI of Sacrum and SI Joints with Contrast

Frequently asked questions

Does this MRI use radiation?
No. MRI uses magnetic fields and radiofrequency waves rather than ionizing radiation.
Why is contrast given through a vein?
Intravenous contrast can highlight inflammation, blood vessels, infection, or other tissue abnormalities and may improve the detail of the images.
Will I feel anything during the scan?
The scanner may make loud knocking sounds, and you may feel pressure from the contrast injection. You should be able to communicate with the imaging technologist during the examination.
  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