Multimodal quantitative magnetic resonance imaging for lumbar intervertebral disc degeneration

The present study investigated the application of the T1ρ and T2 relaxation mapping magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in the evaluation of intervertebral disc degeneration (IDD). A total of 93 asymptomatic subjects were imaged with T1ρ and T2 mapping, as well as DWI. Pfirrmann grading was performed and correlation analysis was conducted for T1ρ, T2 and DWI results with the grading results and age. Pfirrmann grading indicated 69 cases of grade I, 240 cases of grade II, 101 cases of grade III, 43 cases of grade IV and 12 cases of grade V. MRI showed that the T1ρ values of the nucleus pulposi at L4/5 and L5/S1 were significantly reduced (P<0.05) and no significant differences were observed in the T2 values compared with the values of the nucleus pulposus at L1/2, L2/3 and L3/4. The apparent diffusion coefficient (ADC) values of L1/2 were significantly decreased from L2/3 and L3/4 (P<0.05). Correlation analysis revealed that the T1ρ, T, and ADC values were positively correlated with each other. Moreover, the T1ρvalues were significantly decreased with the increase of Pfirrmann grades (P<0.05), with the exception of grades IV and V. However, T2 and ADC values were not significantly different between grades I and II or IV and V. In addition, the T1ρ, T2 and ADC values were significantly decreased with the increase of age in patients with IDD (P<0.05). T1ρ and T2 mapping and DWI are promising techniques for the in vivo diagnosis of IDD, which may be useful in determining the appropriate prevention and treatment options for the disease.