Chemonucleation and changes observed on lumbar MR scan: preliminary report.

This study examines the relation between the postchemonucleation clinical outcome and changes observed on the lumbar MR scan. Eight of 12 chemonucleated disks showed clinical improvement at the last follow-up, while the other four showed no improvement. In the cases that showed improvement there was a decrease in one or both dimensions of the defect in the thecal sac. Seven of eight showed an increase in the peridisk signal. Where there was no clinical improvement there were fewer decreases in the size of the defect, and three of four showed no increase in the peridisk signal.