To compare the effectiveness of Magnetic Resonance Imaging and discography in the diagnosis of internal disc derangement (IDD).

This study was confined to 90 discs of 30 patients diagnosed as IDD by MRI & disco-CT. We compared the pain nature of discogram, degree of annular tear in the disco-CT and degree of disc degeneration in MRI. The presence of HIZ (High Intensity Zone) in MRI was also compared with the pain of discogram.

Those discs with more severe annular tears in the disco-CT showed more definite pain pattern in the discogram. More degeneration in the MRI was also correlated with more anatomical deterioration in disco-CT. Of the 27 discs with normal MRI, 6 (22%) showed severe pain provocation in discography. Of the 63 discs with degeneration in MRI, 14 (22%) showed no pain provocation in discography. Of all discs, HIZ was present in 16% (15/90) . When HIZ was present in a disc of a symptomatic patient, the possibility of it being a painful disc was 93%.

In the diagnosis of IDD, MRI was helpful is seeing the degree of disc degeneration to rule out disc herniation or spinal stenosis. But the discogram is considered the only way for definite diagnosis of painful discs.