Surface Image of Normal Intervertebral Disc on 3 Dimensional CT

ABSTRACT

PURPOSE: To evaluate surface configuration of intervertebral disc on three dimensional CT. MATERIALS AND METHODS: Three dimensional surface images reconstructed from CTscans(1 mm thick) of 20discs in 14 healthy adults were reviewed. Disc surface was classified into peripheral and central zones in contact with consecutive peripheral ring and central endplate. Local irregularity incidence, pattern in radial, concentric, or mixed form, size, location, and extension were observed. Incidence and severity ranges in 4 grades of general irregularity, and peripheral width relative to central radius were evaluated. RESULTS: Normal disc mostly showed smooth surface with few display of small local irregularity(6/20) which was mainly radial in pattern(4/5), posterolaterally located(4/6), and confined within peripheral zone(5/6). General irregularity displayed(5/20) was all grade I and peripheral width was 0.82 of central radius. CONCLUSION: Normal disc shows smooth surface but few may display small local irregularity maybe due to very early degenerative change.