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Comparison of a rapid MR lumbar spine protocol versus a standard protocol for evaluation of degenerative disc disease and neural compromise. 2012

General Spine

Anousheh, Sayah, MD
Frank, Berkowitz, MD, Non ASSR Member

Paper/Non-Mentor

Purpose

Low back pain affects about 50% of U.S. adults annually with medical costs of approximately $20 billion a year. Lumbar MRI costs on average $2000 and takes 30-45 minutes. Reducing MRI scan time while retaining diagnostic accuracy can benefit patients and reduce healthcare costs. Our purpose is to compare the effectiveness of a rapid lumbar MRI protocol consisting of only sagittal T1 and sagittal 3-D T2 SPACE (Sampling Perfection with Application-optimized Contrasts using difference flip angle Evolutions) versus a standard MR protocol for evaluation of lumbar spondylosis.

Methods & Materials

This is an IRB-approved, HIPAA-compliant retrospective review of 100 consecutive non-contrast lumbar MRI studies performed at 1.5T (Magnetom Avanto; Siemens; Germany) Each study was converted into two separate exams; a 'full' exam consisting of sagittal T1, turbo spin echo (TSE) T2, and STIR, and axial T1 and TSE T2 (imaging time: 18:47 min), and a 'rapid' exam consisting of sagittal T1 and T2 SPACE, with axial SPACE reformations (imaging time: 8:40 min). Two fellowship-trained neuroradiologists each independently reviewed 50 separate studies. 'Rapid' exams were reviewed first, followed by 'full' exams several days later. At each disc space between L1 and S1, disc herniations were reported as present or absent. Neural compromise was evaluated in the central regions (central canal and lateral recesses) and lateral regions (foraminal and extraforaminal) and reported as present or absent. Sensitivity and specificity of the 'rapid' exam was calculated using the 'full' study as the standard-of-care.

Results

Of 500 total disc levels evaluated for herniations and neural compromise, the combined discrepancy rate was 2.7%. The sensitivity and specificity of the rapid study was 78.1% and 95.8% for disc herniation; 84.0% and 98.2% for central compromise; and 91.8% and 98.3% for lateral compromise.

Conclusion

The rapid lumbar MRI protocol had high specificity in diagnosing disc herniations and neural compromise, with slightly lower sensitivity. As this protocol can be completed in a 15 minute time slot it can potentially reduce cost for a large subgroup of patients.

References/Financial Disclosures

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