Symptomatic Nerve Root Changes on Contrast-Enhanced MR Imaging after Surgery for Lumbar Disk Herniation

Abstract

BACKGROUND AND PURPOSE:The significance of postoperative nerve root changes (enhancement, thickening, and displacement) is still a topic of debate. The purpose of this study was to evaluate the association between nerve root changes and residual or recurrent symptoms after lumbar surgery with contrast-enhanced MR imaging.

Failed Back Surgery Syndrome

“…This correlation was stronger in the presence of both nerve root thickening and recurrent disc herniation [129]. When NRE was combined with nerve root thickening, the PPV increased to 87.7%, and when recurrent disc herniation was also identified, the PPV increased to 94.1% [129]. Other information that can be revealed by MRI includes stenosis in the lateral recess and neural foramens, diskitis, and pseudomeningocele [68,128].…”

“…Gadolinium‐enhanced MRI helps with the differentiation of scar tissue (postoperative epidural fibrosis) from recurrent or residual disc herniation [128]. Nerve root enhancement (NRE) on postoperative MRI correlates with recurrent or residual symptoms (positive predictive value [PPV] 83.7%) [129]. This correlation was stronger in the presence of both nerve root thickening and recurrent disc herniation [129].…”

“…Nerve root enhancement (NRE) on postoperative MRI correlates with recurrent or residual symptoms (positive predictive value [PPV] 83.7%) [129]. This correlation was stronger in the presence of both nerve root thickening and recurrent disc herniation [129]. When NRE was combined with nerve root thickening, the PPV increased to 87.7%, and when recurrent disc herniation was also identified, the PPV increased to 94.1% [129].…”

Repeated 3.0 Tesla Magnetic Resonance Imaging After Clinically Successful Lumbar Disc Surgery

“…20,21 Contrast enhancement of the nerve root due to inflammation may also occur in patients with persistent or worsened radicular symptoms after lumbar disc surgery, but should not be used for patient selection in the early postoperative phase. 22 Thickening of the nerve root did not occur in successfully operated patients in our study, but is a common nerve root change in patients with persistent pain and can therefore be used as an indicator for unsuccessful lumbar disc surgery. 22 The study strengths are the confirmed acceptable interrater reliability measures of the study parameters, the confirmed clinical treatment success in operated patients, and the use of longitudinal high magnetic field MRI examinations with probably superior imaging quality compared to earlier studies.…”

“…22 Thickening of the nerve root did not occur in successfully operated patients in our study, but is a common nerve root change in patients with persistent pain and can therefore be used as an indicator for unsuccessful lumbar disc surgery. 22 The study strengths are the confirmed acceptable interrater reliability measures of the study parameters, the confirmed clinical treatment success in operated patients, and the use of longitudinal high magnetic field MRI examinations with probably superior imaging quality compared to earlier studies. Although 30 patients are sufficient to assess common postoperative image findings, rare postoperative findings may not be encountered or detected.…”