Characterization of Age‐Related and Sex‐Related Differences of Relaxation Parameters in the Intervertebral Disc Using MR‐Fingerprinting.

Background: Multiparameter characterization using MR fingerprinting (MRF) can quantify multiple relaxation parameters of intervertebral disc (IVD) simultaneously. These parameters may vary by age and sex. Purpose: To investigate age‐ and sex‐related differences in the relaxation parameters of the IVD of the lumbar spine using a multiparameter MRF technique. Study Type: Prospective. Subjects: 17 healthy subjects (8 male; mean age = 34 ± 10 years, range 20–60 years). Field Strength/Sequence: 3D‐MRF sequence for simultaneous acquisition of proton density, T1, T2, and T1ρ maps at 3.0T. Assessment: Global mean T1, T2, and T1ρ of all lumbar IVDs and mean T1, T2, and T1ρ of each individual IVD (L1–L5) were measured. Gray level co‐occurrence matrix was used to quantify textural features (median, contrast, correlation, energy, and homogeneity) from T1, T2, and T1ρ maps. Statistical Tests: Spearman rank correlations (R) evaluated the association between age and T1, T2, and T1ρ of IVD. Mann–Whitney U‐tests evaluated differences between males and females in T1, T2, and T1ρ of IVD. Statistical significance was defined as P‐value <0.05. Results: There was a significant negative correlation between age and global mean values of all IVDs for T1 (R = −0.637), T2 (R = −0.509), and T1ρ (R = −0.726). For individual IVDs, there was a significant negative correlation between age and mean T1 at all IVD segments (R range = −0.530 to −0.708), between age and mean T2 at L2‐L3, L3‐L4, and L4‐L5 (R range = −0.493 to 0.640), and between age and mean T1ρ at all segments except L1‐L2 (R range = −0.632 to −0.763). There were no significant differences between sexes in global mean T1, T2, and T1ρ (P‐value = 0.23–0.76) The texture features with the highest significant correlations with age for all IVDs were global T1ρ mean (R = −0.726), T1 energy (R = −0.681), and T1 contrast (R = 0.709). Conclusion: This study showed that the 3D‐MRF technique has potential to characterize age‐related differences in T1, T2, or T1ρ of IVD in healthy subjects. Level of Evidence: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]