title: Prediction of scoliosis progression with serial three-dimensional spinal curves and the artificial progression surface technique.
abstract: Adolescent idiopathic scoliosis (AIS) progression is clinically monitored by a series of full spinal X-rays. To decrease radiation exposure, an artificial progression surface (APS) is proposed to predict progression. Fifty-six acquisitions (posteroanterior radiographs, 0° and 20°) were obtained from 11 AIS patients (29.8 ± 9.6° Cobb angle). Three-dimensional curves were constructed through vertebral pedicle centers. Three previous serial spinal curves (6-month intervals) were used to construct an APS with a Non-uniform Rational B-Spline surfacing technique. Future progression was achieved by aligning the curves on the APS using the generalized cross-validation extrapolation technique. With three and four previous serial spinal curves, the prediction accuracies of future progression at the next 6-month interval were 4.1 ± 3.3° for Cobb angles and 3.6 ± 3.5 mm for apex lateral deviations. Apex locations and Cobb regions varied within one vertebral level. The proposed technique shows potential as an accurate three-dimensional prediction method for AIS progression and could help pediatricians make decisions about treatment. However, it could only be applied once before more radiographic data would be needed.
authors.affiliation: Department of Mechanical and Manufacturing Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada. howu@ucalgary.ca
authors.forename: Hongfa
authors.initials: H
authors.lastname: Wu
authors.forename: Janet L
authors.initials: JL
authors.lastname: Ronsky
authors.forename: Farida
authors.initials: F
authors.lastname: Cheriet
authors.forename: Jessica
authors.initials: J
authors.lastname: Küpper
authors.forename: James
authors.initials: J
authors.lastname: Harder
authors.forename: Deyi
authors.initials: D
authors.lastname: Xue
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Zernicke
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D011237:Predictive Value of Tests; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000473:pathology; D013997:Time Factors