Published in:
Open Access 01-06-2021 | Magnetic Resonance Imaging | Musculoskeletal
Clinical implementation of accelerated T2 mapping: Quantitative magnetic resonance imaging as a biomarker for annular tear and lumbar disc herniation
Published in: European Radiology | Issue 6/2021
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Objectives
This study evaluates GRAPPATINI, an accelerated T2 mapping sequence combining undersampling and model-based reconstruction to facilitate the clinical implementation of T2 mapping of the lumbar intervertebral disc.
Methods
Fifty-eight individuals (26 females, 32 males, age 23.3 ± 8.0 years) were prospectively examined at 3 T. This cohort study consisted of 19 patients, 20 rowers, and 19 volunteers. GRAPPATINI was conducted with the same parameters as a conventional 2D multi-echo spin-echo (MESE) sequence in 02:27 min instead of 13:18 min. Additional T2 maps were calculated after discarding the first echo (T2-WO1ST) and only using even echoes (T2-EVEN). Segmentation was done on the four most central slices. The resulting T2 values were compared for all four measurements.
Results
T2-GRAPPATINI, T2-MESE, T2-EVEN, and T2-WO1ST of the nucleus pulposus of normal discs differed significantly from those of bulging discs or herniated discs (all p < 0.001). For the posterior annular region, only T2-GRAPPATINI showed a significant difference (p = 0.011) between normal and herniated discs. There was a significant difference between T2-GRAPPATINI, T2-MESE, T2-EVEN, and T2-WO1ST of discs with and without an annular tear for the nucleus pulposus (all p < 0.001). The nucleus pulposus’ T2 at different degeneration states showed significant differences between all group comparisons of Pfirrmann grades for T2-GRAPPATINI (p = 0.000–0.018), T2-MESE (p = 0.000–0.015), T2-EVEN (p = 0.000–0.019), and T2-WO1ST (p = 0.000–0.015).
Conclusions
GRAPPATINI facilitates the use of T2 values as quantitative imaging biomarkers to detect disc pathologies such as degeneration, lumbar disc herniation, and annular tears while simultaneously shortening the acquisition time from 13:18 to 2:27 min.
Key Points
• T
2-GRAPPATINI
, T
2-MESE
, T
2-EVEN
, and T
2-WO1ST
of the nucleus pulposus of normal discs differed significantly from those of discs with bulging or herniation (all p < 0.001).
• The investigated T
2
mapping techniques differed significantly in discs with and without annular tearing (all p < 0.001).
• The nucleus pulposus’ T
2
showed significant differences between different stages of degeneration in all group comparisons for T
2-GRAPPATINI
(p = 0.000–0.018), T
2-MESE
(p = 0.000–0.015), T
2-EVEN
(p = 0.000–0.019), and T
2-WO1ST
(p = 0.000–0.015).