We have used for several years “RACHIS 91” software, yet presented in Montreal last meeting, in 1993. This program is able to achieve a 3D reconstruction of the scoliotic deformity from lateral and frontal x-rays of the full spine. The sight from above (axial view) is often difficult to understand for the physician. A new program has been performed as a clinical support : each torsional segment of the scoliotic spine can be placed in a part of the surface of a cylinder, built either since the lateral or the frontal plan : in this case, it looks like a shield. The torsional segment walks along the concave side of the shield, the length,the surface,the radius and arch of which materialise the spacial displacement of the scoliotic spine from the initial sagittal and medial plan ; the shield’s shape varies as the scoliosis, and the relation between the frontal and the sagittal size of its different parameters is an approach of a 3d measurement.