Influence of Age, BMI, Gender and Lumbar Level on T1. Magnetic Resonance Imaging of Lumbar Discs in Healthy Asymptomatic Adults

Purpose To assess the T1. range of lumbar intervertebral discs in healthy asymptomatic individuals at 1.5 T and to investigate the influence of age, body mass index (BMI), gender, and lumbar level on T1. relaxation. Materials and Methods In a prospective study, a total of 81 volunteers aged 20 - 80 years were included in this study and divided into three age groups (A: 20 - 39y; B: 40- 59y; C: 60 80y). All of the volunteers underwent magnetic resonance imaging (MRI) at 1.5 Twith acquisition of sagittal T1. images. The calculated T1. relaxation times were correlated with age, BMI, gender, and lumbar level relative to the total disc, the annulus fibrosus, and the nucleus pulposus. Results Age had a significant influence on T1. relaxation times at all lumbar levels, with increasing age being associated with reduced relaxation times. There was also a significant difference between age groups A vs. C and B vs. C (P = 0.0008 and P = 0.0149, respectively). No significant differences in T1. relaxation time were observed between men and women (P > 0.05). BMI showed a significant negative correlation with T1. relaxation times (P < 0.0001). Analysis of the lumbar level revealed a significant decrease in relaxation times from L1/2 to L5 /S1 (P = 0.0013). Conclusion Increasing age correlated significantly with advanced lumbar disc degeneration in asymptomatic individuals, particularly in those aged 60 or older. Increasing BMI correlated significantly with increasing degeneration. The lower discs showed more degeneration than the upper ones.