title: [A new approach for evaluation of the rotational deformity in scoliosis. Part I: The development of an apparatus measuring truncal cross-sections and quantitative rotational indices of scoliosis].
abstract: It is indispensable in the diagnosis and treatment of idiopathic scoliosis to estimate the axial rotation deformity as well as the lateral flexion deformity. Because of lack of methodology till now, appropriate quantitative estimation of the former deformity has not been available for the routine clinical use. The purpose of this investigation was to propose a new approach which makes it possible to evaluate the rotational deformity of scoliosis more precisely than ever. To realize an idea that a two-dimentional morphologic measurement through horizontal planes is reasonable for the recognition of the rotational deformity, a new experimental apparatus named Laser Torsograph was constructed for the purpose of measuring horizontal cross-sections of the human body surface. The fundamentals of the measuring system is an optical triangulation using a laser spot which is detected by a line sensor camera. While the laser spot is turned around the trunk horizontally for 360 degrees, input data of the positions of the laser spot on the trunk surface are compiled into a minicomputer and processed to be visualized as cross-sectional figures on a display and X-Y plotter. Each cross-sections thus measured are computerized for the quantitative assessment of the deformity and three parameters (theta, phi, psi) are obtained full-automatically. Theta represents the degree of the spatial rotation of the cross-section (the position change). Phi represents the degree of the distorsion of the cross-section itself (the shape change). Psi represents the difference of thickness between the right and left half of the cross-section. By measuring cross-sections at multi-levels of each spinous processes for a scoliotic patient, the rotational indices of scoliosis are determined as the maximum values of each parameters. As a result of application of Laser Torsography to 109 cases of idiopathic scoliosis, the usefulness of this method has been established. The rotational deformity was obvious on inspection of cross-sections and convincing informations about structural changes were offered which were helpful, for example, to define the curve patterns objectively. Our innovative approach will provide the routine clinical situations with the precise visualization and appropriate quantitative data on the axial rotational deformity in scoliosis.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008433:Mathematics; D008722:Methods; D008905:Minicomputers; D008953:Models, Anatomic; D011859:Radiography; D012399:Rotation; D012600:Scoliosis / Q000175:diagnosis* / Q000000981:diagnostic imaging