Gd-DTPA Enhancement of Lumbar Discs on MRI: Frequency and Pattern

ABSTRACT

PURPOSE: To assess the frequency and pattern of disc enhancement of lumbar spine on enhanced MR images and to determine whether enhanced MR images are useful for locating internal disc lesions. MATERIALS AND METHODS: MR images of a total of 225 discs from 45 patients were reviewed. Fifteen discs from 15 patients who had previously undergone an operation were excluded and 210 discs were therefore studied. T1-, T2-, and gadolinium-enhanced T1-weighted images were obtained after intravenous injection of Gd-DTPA(0.2 ml/kg). Findings were analyzed retrospectively. RESULTS: Sixty-nine(32.6%) of 210 discs showed enhancement. The pattern of enhancement was intradiscal(linear or nodular) or extradiscal. Of 165 morphologically normal discs, 34(20.6%) discs were enhanced; 32 showed linear and two showed nodular enhancement. All of six ruptured discs were enhanced. Six patients were operated on after MRI study ; one case of intradiscal linear enhancement revealed a bulging disc, three of five patients were confirmed on surgery as having ruptured discs in view of the extradiscal enhancement and the other two patients were confirmed having protruded discs. CONCLUSION: The pattern of disc enhancement is classifiedinto intradiscal and extradiscal. The former is further classified into linear and nodular. Gd-DTPA enhanced MRimages may be helpful in diagnosing ruptured discs and in detecting pathologic conditions in those patients whose discs appear to be morphologically normal before enhancement.