(A) MR Neurography demonstrates flattening of the exiting nerve root (**) by a persistent fragment of disc material (fr) in the foramen. The contralateral nerve root (*) has a normal caliber.  

B) 36 year old man with right S1 dysesthetic pain after microdiscectomy. Post-operative imaging showed good decompression, but the Neurography demonstrated persistent hyperintensity of the dorsal root ganglion (DRG) consistent with intraoperative mechanical trauma.  No further surgical treatment was recommended.