Lumbar high-intensity zones on magnetic resonance imaging: imaging biomarkers significantly associated with severe, prolonged low back pain, and sciatica in a population-based cohort

Abstract

INTRODUCTION: High-intensity zones (HIZs) of the lumbar spine on magnetic resonance imaging (MRI) have been noted to occur. However, their clinical relevance has been scrutinised and regarded as purely incidental findings on imaging. However, previous studies largely consisted of small sample sizes, patient-based cohorts, and insufficient assessment of HIZs as well as other MRI findings (e.g. disc degeneration / herniation, Modic changes). As such, the following large-scale study addressed if lumbar HIZs are significantly associated with low back pain (LBP), as well as sciatica and disability, in a population-based cohort. METHODS: This cross-sectional study consisted of 1214 subjects of Southern Chinese origin. T2-weighted 3-Tesla MRI of L1- S1 was performed. Presence and types of HIZs as well as other MRI findings were assessed at each level. Prolonged, severe LBP, sciatica, and Oswestry Disability Index (ODI) were assessed. RESULTS: There were 496 individuals with HIZs and 718 without HIZs. Subject demographics were similar between both groups. Disc degeneration / herniations and not Modic changes were more prevalent in individuals with HIZ (p<0.001). Based on adjusted multivariate regression analyses, individuals with multilevel disc involvement of homogeneous or heterogeneous HIZ types were significantly associated with LBP (range of odds ratio [OR]: 1.53-1.57; p<0.05). Individuals with multilevel homogenous HIZs had a higher risk of sciatica (OR: 1.51, 95% confidence interval: 1.01-2.27), whereas other HIZ types were not. With respect to disability, HIZs were not found to be significantly related (p>0.05). CONCLUSIONS: This is the first large-scale study to note that HIZ types are independent and clinically relevant imaging biomarkers associated with prolonged, severe LBP, and sciatica.