Figure 1. Spiral CT work-up. (a) Mid-sagittal reformatted image at the T9–T10 level showing intracanalar protrusion of two supernumerary bone outgrowths originating from the posterior elements. Observe cortical/spongy differentiation of the abnormal "bones", and pseudoarthritic changes at their interface, with focal cortical thickening and "degenerative" geode filled with air at the caudal aspect of the "pseudoarthrosis" (arrow). (b) Axial transverse reformatted image through the T9 level showing perfect cortical/spongy differentiation of abnormal ossicles together with calcifications of the ligamenta flava from which they are originating. (c) Axial transverse reformatted image through the T10 level showing pseudoarthritic thickening of the inferior border of the "pseudoarthosis", and the same air-filled geode as in Figure 1a (arrow). (d) Frontal reformatted image, well disclosing the pseudoarthritic interface between the two supernumerary ossicles. Their origin from posterior elements is obvious.