Lumbar degenerative disk disease: prospective comparison of conventional T2-weighted spin-echo imaging and T2-weighted rapid acquisition relaxation-enhanced imaging.

Purpose: To compare conventional T2-weighted spin-echo imaging with a rapid acquisition relaxation enhanced (RARE) technique in the routine evaluation of lumbar degenerative disk disease.
Methods: Thirty consecutive patients referred for evaluation of the lumbar spine for suspected degenerative disk disease were evaluated with sagittal and axial T1-weighted spin-echo, conventional T2-weighted spin-echo, and T2-weighted RARE "turbo spin-echo" sequences (4000/93/2 (repetition time/echo time/excitations), 192 x 256, echo train length of 8). Conventional T2-weighted and RARE images were evaluated independently by two neuroradiologists for image quality, presence of artifacts, cerebrospinal fluid signal intensity, extradural interface conspicuity, intradural nerve root conspicuity, soft-tissue detail, and signal intensity of normal and degenerated intervertebral disks.
Results: Both readers rated the cerebrospinal fluid signal higher, the extradural interface conspicuity higher, and the nerve root detail greater on the turbo spin-echo than on conventional spin-echo images. Neither reader had a significant difference in ranking "normal" or "degenerated" disk signal on the two sequences. Both readers rated soft-tissue detail higher for conventional than for turbo spin-echo.
Conclusion: RARE sequences can replace conventional T2-weighted spin-echo sagittal studies for degenerative lumbar disk disease.