THE VALUE OF LUMBAR SPINE MAGNETIC-RESONANCE-IMAGING IN THE DEMONSTRATION OF ANULAR TEARS

Study Design. Retrospective review of magnetic resonance imaging and d iscography in patients investigated for low back pain before spinal fu sion. Objective. To determine the sensitivity of magnetic resonance im aging in the detection of painful anular tears manifested by the high- intensity zone. Summary of Background Data. Two studies have produced results showing that magnetic resonance imaging has a high specificity for the detection of painful anular tears manifested by a high-intens ity zone. However, in a recent study, results showed no significant co rrelation between the high-intensity zone and pain reproduction. The s ensitivity of magnetic resonance imaging in identifying anular tears i n a symptomatic population has not been determined. Methods. Anular te ars were identified in magnetic resonance images by the presence of a high-intensity zone in the posterior anulus. The results were com; par ed with the demonstration of painful anular tears on discogram, which has been considered the gold standard. Results. The study group compri sed 58 patients (31 men, 27 women; mean age 42, range 21-63 years). On e hundred and fifty-two discs were injected and examined by discograph y, and 108 were considered degenerate. Of these, 86 had anular tears ( 54 posterior, 6 anterior, 26 both). Seventy anular tears were associat ed with concordant pain provocation. Twenty-seven high-intensity zones were identified in magnetic resonance imaging, of which 24 were assoc iated with pain reproduction by discography. The sensitivity, specific ity, positive predictive value, and negative predictive value of magne tic resonance imaging in the diagnosis of concordantly painful posteri or anular tears are therefore 26.7%, 95.2%, 88.9%, and 47%, respective ly. Conclusion. These results confirm that the high-intensity zone is a marker of a painful posterior anular tear. However, the usefulness o f this sign is limited by low sensitivity.