Postoperative lumbar intradiskal and epidural contrast enhancement on Gd-DTPA MR images

This paper reports the postoperative lumbar spine and disks evaluated with Gd-DTPA MR imaging (T1-weighted spin echo [SE] 800/20 [ repetition time msec/echo time msec], 1.5 T) in 23 patients (aged 27-86 years; mean, 49 years) who were imaged 2 months to 18 years (21 patients; mean age, 41 years) and at 50 and 54 years after lumbar diskectomy (25 disk levels). Abnormal enhancement was seen in epidural fibrosis (21 of 25 disk levels), within disk margins (intradiskal, 18 of 25), and at margins of recurrent HNP (three of 25). Epidural enhancement was seen from 2 months to 18 years postoperatively and was clearly distinguished from nonenhancing recurrent HNP. Intradiskal enhancement occurred in three patterns: posterior disk and along end plates (PDEP, 10 of 18 cases); posterior disk only (PD, six of 18 cases); and in thin, collapsed disk remnants (CD, two of 18)