Lumbar Spine and Sacroiliac Joint MRI

Combined MRI of the lumbar spine and sacroiliac joints. Essential for differentiating mechanical lower back pain from inflammatory sacroiliitis and axial spondyloarthropathy.

This combined examination extends the standard lumbar spine protocol to include dedicated imaging of both sacroiliac (SI) joints. The addition of coronal oblique STIR and T1 sequences through the SI joints allows the radiologist to detect bone marrow oedema, erosions, sclerosis, and ankylosis — the hallmarks of sacroiliitis that may indicate ankylosing spondylitis or other forms of axial spondyloarthropathy. The lumbar component follows the standard L1-S1 protocol, while the SI joint component uses sequences aligned to the long axis of the sacroiliac joints for optimal assessment of the joint surfaces and periarticular bone. This combined approach is more cost-effective than separate bookings and ensures that both potential pain generators are evaluated in a single session. The examination is commonly requested by rheumatologists investigating inflammatory back pain in younger patients, by orthopaedic surgeons evaluating SI joint dysfunction, and by patients with lower back and buttock pain where the clinical distinction between lumbar and sacroiliac origin is unclear.