Volumetric measurement of herniated disc material as a predictor of outcome in periradicular therapy

The aim of this study was to analyze the correlation between volume change in disc herniations and pain improvement after CT guided periradicular therapy.

Between 5/2017 and 9/2023 46 volumetric MRI examinations of 18 patients suffering from lower back pain were compared to a control group, prior to and following periradicular infiltration therapy. The performed procedure included an image guided application of a glucocorticoid, a local anesthetic and a contrast agent close to the affected nerve root. An additional 3D MRI-dataset was acquired to perform the volumetric analysis. The measurement was conducted using a manual 3D tool independently by two experienced physicians twice. For measurement and calculation of correlation, the average value of the four measurements per examination was used. We assessed the volume-change of the herniated discs in follow-up examinations in both groups as well as change of pain score under and without therapy.

Under interventional pain therapy, the herniated disc volume was significantly reduced compared to the control group. In the intervention group, the disc volume was reduced by an average of 20,4% whereas the disc volume in the control group increased by an average of 33,6%. There was an improvement of pain score of 4.4 points in the intervention group whereas the control group showed a worsening of 1.2 points.

Periradicular CT-guided infiltration leads to significant volume reduction of herniated discs compared to non-treated patients. Furthermore, a correlation between change of volume of the herniated disc and an improvement of pain score over time could be observed.