SI Joint MRI in St. Louis — $399 Flat Rate
SI joint MRI uses an angled protocol aimed directly at the sacroiliac joints. It can detect early sacroiliitis, inflammation that often shows on MRI before it shows on X-ray.
A doctor's order is required — your provider can fax it to (314) 804-7226.
A Doctor's Order Is Required
We require a doctor's order before we can perform an MRI, and so do Medicare and most insurance plans. No order yet? We can help you get one — most patients arrange it in a day or two.
What the Radiologist Looks For
- Active sacroiliitis with bone marrow edema
- Structural changes: erosions, sclerosis, ankylosis
- Axial spondyloarthritis findings
- Degenerative SI joint disease
- Sacral stress fractures
Who Orders This
Ordered by rheumatologists for inflammatory back pain — morning stiffness over 30 minutes, pain improving with activity, onset before age 45, or in HLA-B27-positive patients.
How to Prepare
- No fasting or special preparation.
- Empty your bladder before the scan.
- Gown required — no metal below the waist.
- Bring prior SI or pelvic imaging if you have it, since comparison matters here.
Common Questions
X-ray only shows structural damage after it has built up, often several years into the disease. MRI can show active inflammation sooner, which is what changes treatment decisions.
Yes, and it matters. A standard lumbar study does not angle through the SI joints properly and routinely under-reads sacroiliitis. Book the SI protocol if that is the question.
New to MRIs? Read our complete guide to what to expect · More questions? See all FAQs · Read patient reviews
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Request Your SI joints MRI
Flat rate $399. No insurance required. Same-day appointments by phone.