Diagnostic and Interventional MRI of the Sacroiliac Joints Using a 1.5-T Open-bore Magnet: a One-stop-shopping Approach

Objective: The objective of our study was to prospectively test the hypothesis that combined diagnostic and interventional MRI of the sacroiliac joints can be performed efficiently and effectively.

Subjects And Methods: Over a 12-month period, 60 patients (32 women and 28 men; median age, 28 years; age range, 18-49 years) with chronic lower back pain suspected to originate from the sacroiliac joints were enrolled in the study. Based on diagnostic MRI findings, MR fluoroscopy-guided sacroiliac joint injections were performed in 57 (95%) patients. Diagnostic injections (35, 58.3%) were performed if nonspecific or degenerative MRI findings were present. Therapeutic injections (22, 36.7%) were performed in patients with inflammatory arthropathy. In three (5%) patients, no injections were performed. Technical effectiveness was assessed by analyzing, first, the rate of intraarticular injection; second, the time required for the procedure; third, image quality; and, fourth, occurrence of complications and clinical outcome by analyzing pain intensity changes and volume and signal intensity of sacroiliac inflammatory changes.

Results: The rate of intraarticular injection was 90.4% (103/114). The mean length of time for the procedure was 50 minutes (range, 34-103 minutes), with exponential shortening over time (p < or = 0.001). The contrast-to-noise ratios of the needle and tissues were sufficiently different for excellent delineation of the needle. No complications occurred. Diagnostic injections identified the sacroiliac joints as generating significant pain in 46.9% (15/32) of the patients. Three months after therapeutic injections, pain intensity had decreased by 62.5% (p < or = 0.001) and the volume and relative signal intensity of inflammatory changes had decreased by 37.5% (p = 0.003) and 47.6% (p < or = 0.001), respectively.

Conclusion: We accept the hypothesis that combined diagnostic and interventional MRI of the sacroiliac joints can be performed efficiently and effectively for comprehensive diagnosis and therapy of lower back pain originating from the sacroiliac joints.