Abstract / Summary
This study aimed to investigate the potential of synthetic Magnetic Resonance Imaging (MAGiC) in quantitatively assessing age- and sex-related changes in lumbar paraspinal muscles and their correlation with muscle strength. A total of 198 adult volunteers (92 males, 106 females; mean age 47.6 ± 16.01 years) were enrolled. All participants underwent MAGiC sequence scanning at the L3 vertebral level on a 3.0T MRI scanner. Quantitative T1, T2, and proton density (PD) values of the Erector Spinae (ES) and Multifidus (MF) muscles were obtained. Handgrip strength (HGS) was measured using a hydraulic dynamometer. Statistical analyses were performed to assess sex differences, correlations with age, and relationships with HGS. Significant sex differences were found in quantitative T2 values for all measured muscles (MF, ES, ES + MF), being lower in males than females ( p < 0.001). T1 of the MF was significantly higher in males ( p = 0.027). In the total population, T1 values of the paraspinal muscles showed a moderate negative correlation with age (r range: -0.302 to -0.362, p < 0.001), while T2 values showed a strong positive correlation with age (r range: 0.610 to 0.635, p < 0.001). PD values showed no significant correlation with age. Linear regression analysis also showed that age was correlated to T1 (β = -1.10, 95% confidence interval (CI): -2.00 to − 0.20; β = -1.46, 95% CI: -2.19 to − 0.73; β = -1.42, 95% CI: -2.16 to − 0.68) and T2 (β = 0.38, 95% CI: 0.30 to 0.46; β = 0.34, 95% CI: 0.28 to 0.39; β = 0.35, 95% CI: 0.29 to 0.41) values of MF, ES, and ES + MF after controlling sex and body mass index (BMI). After stratifying by sex, T2 remained strongly positively correlated with age in both genders. T1 was negatively correlated with age in females but not in males. Linear regression analysis showed similar trends. HGS showed a significant positive correlation with T1 values and a stronger negative correlation with T2 values across all muscle groups in the total population and within each gender. PD was not correlated with HGS. Quantitative T1 and T2 values derived from the MAGiC sequence effectively detect age- and sex-related changes in lumbar paraspinal muscles and are significantly correlated with muscle strength. These quantitative MR parameters show promise as objective imaging biomarkers for the assessment of age-related changes in muscle quality. Not applicable.