Comparison of lumbar degenerative disc disease using conventional fast spin echo T2W MRI and TT2 fast spin echo dixon sequences.

OBJECTIVES To compare the grading of lumbar degenerative disc disease (DDD), Modic end-plate changes (MEPC) and identification of high intensity zones (HIZ) on a combination of sagittal T2 weighted turbo spin echo (T1W TSE), T2 weighted fast spin echo (T2W FSE) and short tau inversion recovery (STIR) sequences (routine protocol) with a single sagittal T2W FSE Dixon MRI sequence which provides in-phase, opposed-phase, water only and fat only images in a single acquisition (Dixon protocol). METHODS 50 patients underwent lumbar spine MRI using the routine protocol with the addition of a T2W FSE Dixon sequence. DDD grade, MEPC and HIZ for each disc level were assessed on the routine and Dixon protocols. Each protocol was reviewed independently by three readers (consultant musculoskeletal radiologists with 26-, 8- and 4 years' experience), allowing assessment of inter-reader agreement and inter protocol agreement for each assessed variable. RESULTS The study included 17 males and 33 females (mean age 51 years; range 8-82 years). Inter-reader agreement for DDD grade on the routine protocol was 0.57 and for the Dixon protocol was 0.63 (p = 0.08). Inter-reader agreement for MEPC on the routine protocol was 0.45 and for the Dixon protocol was 0.53 (p = 0.02), and inter-reader agreement for identification of the HIZ on the routine protocol was 0.52 and for the Dixon protocol was 0.46 (p = 0.27). Intersequence agreement for DDD grade ranged from 0.61 to 0.97, for MEPC 0.46-0.62 and for HIZ 0.39-0.5. CONCLUSION A single sagittal T2W FSE Dixon MRI sequence could potentially replace the routine three sagittal sequence protocol for assessment of lumbar DDD, MEPC and HIZ resulting in ~60% time saving. ADVANCES IN KNOWLEDGE Grading of lumbar DDD, presence of Modic changes and high intensity zones were compared on sagittal T1W TSE, T2W FSE and STIR sequences with a T2W FSE Dixon sequence, with fair-to-good correlation suggesting that three conventional sequences could be replaced by a single Dixon sequence.