CT Scan S I Joint

Yes. CT provides excellent bone detail and can detect sacroiliac joint problems such as erosions, sclerosis, ankylosis, fractures and degenerative changes. It is superior to X‑ray for structural abnormalities but less sensitive than MRI for early inflammatory changes or bone marrow edema. Clinicians often use CT to assess chronic structural damage or when X‑rays are inconclusive; MRI is preferred for active sacroiliitis.

SI on a CT scan usually refers to the sacroiliac (SI) joint — the articulation between the sacrum and ilium. CT evaluates SI joints for arthritis, sacroiliitis, fractures, infection, or fusion; findings include joint-space narrowing, erosions, sclerosis, or ankylosis. SI joint assessment is common in pelvic or lower-spine imaging to explain low back or buttock pain.

Yes. CT scans show joint problems affecting bone: fractures, alignment, bone erosions, osteoarthritis and bony contributions to pain, and are excellent for complex or pre‑operative assessment. Standard CT is limited for soft tissues (cartilage, ligaments, tendons); MRI is preferred for those. CT arthrography can better visualize cartilage and labral tears. CT uses ionizing radiation, so benefits and risks are weighed.

MRI is the best imaging for sacroiliac joints to detect early sacroiliitis and active inflammation (using STIR or T2 fat‑sat sequences). CT is superior for detailed assessment of chronic bony changes, erosions and sclerosis. Plain X‑rays are less sensitive and often miss early disease. Choice depends on the clinical question: inflammation (MRI) vs structural damage (CT).

The definitive test to confirm sacroiliac (SI) joint dysfunction is a diagnostic intra‑articular SI joint injection of local anesthetic performed under fluoroscopic or CT guidance; significant pain relief confirms the SI joint as the pain generator. Provocative physical exam maneuvers (FABER, Gaenslen, thigh‑thrust, compression/distraction) and imaging (X‑ray, MRI) help support the diagnosis.

SI joint pain is often manageable and can improve long-term with targeted physical therapy, activity modification, medications, and injections. Many people achieve lasting relief, but a guaranteed permanent cure is uncommon. For select patients with persistent symptoms, surgical fusion can provide substantial long-term improvement, though success varies and recurrence or residual pain may occur. Ongoing self-care reduces relapse risk.