Imaging Analysis of the High-Intensity Zone on Lumbar Spine Magnetic Resonance Images: Classification, Features and Correlation with Low Back Pain

AIM: Early studies suggested that the high-intensity zone (HIZ) on lumbar MRI was a diagnostic sign of painful internal disc disruption (IDD). However, recent studies have questioned its diagnostic value. This study is conducted to explore imaging features of HIZ and to investigate the correlation between these characteristics and low back pain (LBP), further studying the predictive value of HIZ. METHODS: A retrospective study of 1188 cases was performed. MR images were read and analyzed by two experienced, blinded radiologists. RESULTS: A total of 575 (48.4%) individuals exhibited HIZ. The prevalence of posterior HIZ (32.3%) was significantly higher than that of anterior HIZ (23.6%; P < 0.01). Round type was the most common shape (61.0%) on sagittal view. Only 37 HIZs (4.6%) were identified on axial views. A total of 263 HIZ discs (32.5%) were found to have additional diagnostic signs of IDD, which is difficult to distinguish from the annulus fibrosus. In subjects with consecutive slides showing HIZ, the incidence of LBP was significantly higher than in single-slide HIZ individuals (58.0% vs 48.6%, P < 0.05). CONCLUSION: MRI-visualized HIZ is a highly valuable method of screening for lumbar IDD. It is demonstrated that consecutive-slide HIZ was a more reliable indicator for discogenic LBP than single-slide HIZ.