Longitudinal study of high intensity zones on MR of lumbar intervertebral discs

AIM: To study the temporal evolution of high intensity zones (HIZ) on MRI in patients with degenerative disease of the lumbar spine, and to evaluate whether any correlation exist between such evolution and in patient's symptoms. MATERIALS AND METHODS: HIZs in the MRI of 56 patients were included in the study. Each Patient had an initial and a follow-up scan performed at various time intervals. Scans were assessed for any change in HIZs by two observers (D. M. and I. W. M.). Patients' symptoms were assessed for by visual analogue score (VAS), the Oswestry Questionnaire Score (OQS) and patients' subjective assessment of change in symptoms. Any MRI feature, apart from HIZs, which could independently explain a patient's change in symptoms, was considered to be a confounding factor. Data were analysed separately in the whole group as well as in the group without confounding factors. RESULTS: On follow-up MRI, HIZs were found to have resolved in 17 lumbar disc levels (26.6%), improved in 9 (14%), worsened in 12 (18.8%) and remained unchanged in 26 (40.6%) at lumbar disc levels. Chi-square testing did not demonstrate any correlation between HIZ changes and evolution of patients' subjective symptoms (p=0.26 for the whole group; p=0.07 for the group without confounding factors). Similar lack of meaningful relationship was noted between HIZ changes and the VAS and OQS scores. CONCLUSION: We conclude that HIZs either do not change or improve spontaneously in a large proportion of cases over a period of time. Furthermore, there is no statistical correlation between HIZ changes and change in a patient's symptoms