High-intensity zone (HIZ) of lumbar intervertebral disc on T2-weighted magnetic resonance images: spatial distribution, and correlation of distribution with low back pain (LBP)

To analyze the three-dimensional distribution of high-intensity zone (HIZ) in lumbar disks and to assess the correlation between low back pain (LBP) and spatial distribution of HIZs.

Clinical records and lumbar MRIs of 623 patients (337 males and 286 females, age 50.10 ± 15.38 years) were selected and reviewed. Baseline characteristics and 3D localization were performed and recorded by two radiologists in a blind fashion.

Among the 623 patients, 200 exhibited an HIZ in at least one disk. HIZs were more frequently seen in the inferior part of annulus fibrosus (superior–middle–inferior ratio 39:59:140, P < 0.001). One hundred and eighty-one HIZs (76.1%) occurred at L4/5 and/or L5/S1. The prevalence of multi-segmental HIZ was 16.5%. Among the 33 patients with multi-segmental HIZs, 24 exhibited HIZs in adjacent disks. The LBP rate of HIZ patients was significantly higher than that of patients who exhibited no HIZ (57.5 vs. 47.8%, P < 0.05). There was no evidence for a correlation between LBP and spatial distribution of HIZ in disk (P > 0.05). The incidence of LBP was slightly higher when the HIZ disk level was lower or when there were HIZs exhibited in more disks; however, the difference was statistically insignificant (P > 0.05).

High-intensity zones occurred frequently at lower segments, inferior part of annulus fibrosus, and single disk.