Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc.
BACKGROUND
Magnetic resonance imaging (MRI) T2 mapping utilizes the T2 values for quantification of moisture content and collagen sequence breakdown. Recently, attempts at quantification of lumbar disc degeneration through MRI T2 mapping have been reported. We conducted an analysis of the relationship between T2 values of degenerated intervertebral discs (IVD) and chronic low back pain (CLBP).


METHODS
The subjects who had CLBP comprised 28 patients (15 male, 13 female; mean age 48.9 ± 9.6 years; range 22-60 years). All subjects underwent MRI and filled out the low back pain visual analog scale (VAS) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The disc was divided into the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF, and each T2 value was measured. This study involved 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 male, 12 female; mean age 43.8 ± 14.5 years; range 23-60 years). These subjects had no low back pain, and constituted the control group.


RESULTS
T2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different within the posterior AF. The correlation coefficients between the VAS scores and T2 values of anterior AF, NP and posterior AF were r = 0.30, -0.15 and -0.50. The correlation coefficient between the JOABPEQ scores (low back pain) and T2 values of anterior AF, NP and posterior AF were r = -0.0041, 0.11 and 0.42. Similarly, the JOABPEQ scores (lumbar function) were r = -0.22, -0.12 and 0.57.


CONCLUSIONS
The results indicated a correlation between posterior AF degeneration and CLBP. This study suggests that MRI T2 mapping could be used as a quantitative method for diagnosing discogenic pain.