The critical role of 3-D CT reconstructions for defining spinal disease.

Three dimensional processing of routine CT images has previously been applied to osseous related maxillo-facial and spinal disorders. Two groups of patients, 25 with substantial spinal trauma and 25 with 'failed back' syndrome had 2-D and 3-D like displays processed by the Cemax 1000 system. The goal was to objectify whether the adjunct of 3-D imaging was truly valuable diagnostically. All images were recorded on 35 mm slides and projected both randomly and as an organized case; intra- and interpersonal evaluations were made. 3-D imaging in 19 of the 25 (76%) trauma patients disclosed additional diagnostic information which was considerably important to both the neuroradiologist and the referring surgeon. In the 'failed back' group, the 3-D images showed supplementary information in 15 of 25 (60%) cases. 3-D displays were usually in color showing complete regional information obtained from high resolution, medium thickness (4 mm) CT slices with minor overlapping (1 mm). The displays were optimized to the plane best defining the pertinent osseous and joint morphology; this included variably rotated and sometimes hemisected views. The images presented here are static, however, when viewed rapidly or by dynamic rotation, the regional morphology results in a highly graphic 3-D presentation.