Thein vivoandex vivomicroanatomic appearance of early disc degeneration were identified by magnetic resonance imaging and correlated with their respective histoipathologic findings. Five cadaver spines (18 discs) and 25 patient studies (122 discs) all imaged at 1.5 Tesla were studied. Two signs of early degenerative disc disease were found: infolding and the central dot. Infolding of the central fibers of the outer annulus coalesced into a central dot of low signal intensity that was seen on both theex vivoandin vivoimages. Infolding was seen 29 of 122 times, and the central dot was observed 15 of 122 times on thein vivoimages. A later form of degenerative disc disease was identified as a separation of the nucleus pulposus from the hyaline cartilage end-plate. This separation was seen as a linear area of either low or high signal intensity on theex vivoimages but only as a band of high signal intensity on thein vivospin-echo 2,500-msec/80-msec images. Only 7 of 122in vivodiscs showed this separation. Internal herniation of nucleus pulposus into the outer annulus was seen only on theex vivoimages. Early degenerative disc disease may exist before there is loss of disc height or signal intensity on the long time-to-repetition (TR)/time-to-echo (TE) magnetic resonance images.