What imaging is required for sacroiliac (SI) joint fusion?

From the Guidelines

Imaging for sacroiliac (SI) joint fusion should include radiography of the sacroiliac joints as the initial imaging, followed by MRI of the sacroiliac joints if necessary, as recommended by the American College of Radiology 1. When evaluating a patient for SI joint fusion, it is essential to prioritize imaging modalities that provide the most accurate diagnosis and treatment planning.

• The initial imaging should include radiography of the sacroiliac joints, which is usually appropriate as the initial imaging of suspected axial spondyloarthritis (axSpA) 1.
• If radiography is inconclusive, MRI of the sacroiliac joints without and with IV contrast may be considered as the next imaging study, as it provides detailed evaluation of the SI joint anatomy and helps identify bone marrow edema, inflammation, and soft tissue pathology around the SI joint 1.
• Other imaging modalities, such as computed tomography (CT) scans, may also be useful in certain cases, but are not typically recommended as the initial imaging for SI joint fusion.
• The choice of imaging modality should be based on the individual patient's needs and medical history, as well as the surgeon's preference and experience.
• It is crucial to note that the American College of Radiology recommends radiography and MRI as the primary imaging modalities for evaluating SI joint fusion, and other imaging modalities should be used judiciously and only when necessary 1.

From the Research

Imaging Requirements for Sacroiliac Joint Fusion

The following imaging modalities are used for sacroiliac (SI) joint fusion:

• X-ray fluoroscopy, including biplanar x-ray fluoroscopy for intraoperative guidance 2
• Computed Tomography (CT) scans, including abdominal CT and SI joint CT, for diagnosis and assessment of sacroiliitis 3, 4
• Magnetic Resonance (MR) imaging, which can be fused with ultrasound images to guide intra-articular injections 5
• Radiography, including pelvic plain radiography, for diagnosis of structural sacroiliitis 4

Key Findings

• Biplanar x-ray fluoroscopy allows for simultaneous anteroposterior and lateral projections, reducing procedure time and improving accuracy 2
• CT scans, particularly SI joint CT, are considered the reference technique for diagnosing structural sacroiliitis 4
• MR imaging can be used to guide intra-articular injections and has been shown to be effective in reducing pain 5
• Radiographic imaging evaluation, including implant placement accuracy and fusion, is an important aspect of SI joint fusion procedures 6

Imaging Modalities for Specific Procedures

• Minimally invasive SI joint fusion procedures, including transiliac and posterior interpositional procedures, often utilize x-ray fluoroscopy and CT scans for guidance and assessment 6
• SI joint injections, including diagnostic and therapeutic blocks, may use ultrasound-MR image fusion guidance 5