Role of magnetic resonance diffusion tensor imaging in assessment of back muscles in young adults with chronic low back pain

Abstract

Background Low back pain (LBP) is one of the most common musculoskeletal complaints and considered as the most disabling condition among general population. Magnetic resonance imaging (MRI) is the preferred modality in imaging of LBP. Diffusion tensor imaging (DTI) is a version of MRI that can detect tissue microstructure changes occurring in different pathologies. The commonly used parameters are fractional anisotropy (FA) and mean diffusivity (MD). We aimed in this study to evaluate the role of DTI in the assessment of back muscles in young adults with chronic LBP with no major neurological or orthopedic disorders. Results There was a statistically significant difference in MD values of back muscles between patients and control groups. At the ROC curve, for psoas muscle, the AUC was 0.906 with a cutoff point of 0.951. Sensitivity and specificity were 89.2% and 90.9% with accuracy 89.8%. For multifidus muscle, the AUC was 0.919 with a cutoff point of 1.29. Sensitivity and specificity were 91.9% and 90.9% with accuracy 91.4%. For erector spinae muscle, the AUC was 0.834 with a cutoff point of 1.224. Sensitivity and specificity were 81.1% and 72.7% with accuracy 77.9%. There was a statistically significant difference in FA values of back muscles between the patients and control groups. At the ROC curve, for psoas muscle, the AUC was 0.840 with a cutoff point of 0.546. Sensitivity and specificity were 81.1% and 72.7% with accuracy 77.97%. For multifidus muscle, the AUC was 0.875 with a cutoff point of 0.415. Sensitivity and specificity were 81.1% and 90.9% with accuracy 84.7%. For erector spinae muscle, the AUC was 0.805 with a cutoff point of 0.437. Sensitivity and specificity were 81.1% and 77.3% with accuracy 79.7%. Conclusions DTI is a valuable promising noninvasive tool in the assessment of back muscles quality in patient with chronic low back pain, with no detected neurological or orthopedic pathologies. This is due to its sensitivity to microscopic intracellular changes that could not be detected on conventional imaging, allowing better tissue characterization.