RECURRENT DISK VERSUS SCAR IN THE POSTOPERATIVE-PATIENT - THE ROLE OFCOMPUTED-TOMOGRAPHY (CT) DISKOGRAPHY AND CT MYELOGRAPHY

The purpose of this study was to compare computed tomography (CT)/myel ography and CT/diskography images, in a given patient, as a method of distinguishing postoperative fibrosis from recurrent herniated disk ma terial. The study population consisted of 20 patients who had undergon e lumbar diskectomy and subsequently developed recurrent radicular pai n. All patients underwent CT/myleography and CT/diskography, each proc edure performed within 72 h of the other. Comparison of transaxial ima ges from CT/myelography and CT/diskography at a given disk space level yielded the following results: in 12 patients the extradural mass see n via CT/myelography corresponded entirely to the contrast-filled disk fragment seen via CT/diskography (recurrent herniated disk); in three patients the extradural mass seen via CT/myelography was larger than the disk fragment seen via CT/diskography (recurrent herniated disk an d fibrosis); and in five patients CT/diskography images appeared norma l, but CT/myelography showed an extradural mass (fibrosis). Fifteen pa tients underwent surgical reexploration with the following results: in three of three patients, the suspicion of recurrent herniated disk an d fibrosis by radiologic evaluation was confirmed by surgical reexplor ation; in nine of 12 patients, solely recurrent herniated disk shown b y radiologic criteria was similarly confirmed. The remaining five pati ents presumed to have fibrosis by radiologic criteria were treated non operatively.