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, T 1 , T 2 , and T 1ρ maps at 3.0T. Assessment Global mean T 1 , T 2 , and T 1ρ of all lumbar IVDs and mean T 1 , T 2 , and T 1ρ 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 T 1 , T 2 , and T 1ρ maps. Statistical Tests Spearman rank correlations ( R ) evaluated the association between age and T 1 , T 2 , and T 1ρ of IVD. Mann–Whitney U‐tests evaluated differences between males and females in T 1 , T 2 , and T 1ρ 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 T 1 ( R = −0.637), T 2 ( R = −0.509), and T 1ρ ( R = −0.726). For individual IVDs, there was a significant negative correlation between age and mean T 1 at all IVD segments ( R range = −0.530 to −0.708), between age and mean T 2 at L2‐L3, L3‐L4, and L4‐L5 ( R range = −0.493 to 0.640), and between age and mean T 1ρ at all segments except L1‐L2 ( R range = −0.632 to −0.763). There were no significant differences between sexes in global mean T 1 , T 2, and T 1ρ ( P ‐value = 0.23–0.76) The texture features with the highest significant correlations with age for all IVDs were global T 1ρ mean ( R = −0.726), T 1 energy ( R = −0.681), and T 1 contrast ( R = 0.709). Conclusion This study showed that the 3D‐MRF technique has potential to characterize age‐related differences in T 1 , T 2, or T 1ρ of IVD in healthy subjects. Level of Evidence 2 Technical Efficacy Stage 1