MR Findings of Degenerative Changes of Nucleus Pulposus in Lumbar Spine'Sequential Changes after Disc Herniation

ABSTRACT

PURPOSE: To evaluate the relationship between MR changes of the nucleus pulposus and the time interval after traumatic disc herniation. MATERIALS AND METHODS: T2-weighted MR images of 132 patients with back pain and/or sciatica were reviewed. The changes of signal intensity, central cleft and height of the nucleus pulposus were used as criteria of disc degeneration and they were graded as normal, mild, moderate and severe degrees of degeneration. Putting these criteria together we provided integrated grade of degeneration of the nucleus pulposus(grade 0-3). To get the preliminary data for normal and age-related disc degeneration, we measured the disc height by age groups and disc levels and analyzed the realtionship between the age of the patients and the signal intensity, cleft and height in normal disc levels of the 132 patients. In 68 patients of 88 levels disc herniation, we analyzed the relationship between symptom duration and the degree of degeneration. Among these 68 patients we selected 14 patients(16 levels) who were under 30 years of age and had history of recent trauma to minimize data distortion from age related degeneration and ambiguity of initiation point of degeneration. In this group we analyzed the relationship between the time period after traumatic disc herniation and the degree of degeneration. RESULTS: The age of the patient had close relationship with the grade of signal intensity, central cleft, and disc height and grade of degeneration of the nucleus pulposus in normal discs. in 88 levels of herniated discs, the duration of symptom and degree of degeneration showed moderate correlation. In 14 patients of disc herniation who were under 30 years old and had trauma history in recent 2 years, grade 1 disc degeneration occured in average 3.7 months after trauma. CONCLUSION: Although it was difficult to proceed statistical analysis in the last group because of small patients number, the degree of degeneration of nucleus pulposus had close relationship with the duration after traumas or duration of symtoms.