title: 3-D reconstruction of the spine from biplanar radiographs based on contour matching using the Hough transform.
abstract: The purpose of this study was to develop and evaluate a method for three-dimensional (3-D) reconstruction of the spine from biplanar radiographs. The approach was based on vertebral contour matching for estimating vertebral orientations and locations. Vertebral primitives were initially positioned under constraint of the 3-D spine midline, which was estimated from manually identified control points. Vertebral orientations and locations were automatically adjusted by matching projections of 3-D primitives with vertebral edges on biplanar radiographs based on the generalized Hough transform technique with a deformation tolerant matching strategy. We used graphics processing unit to accelerate reconstruction. Accuracy and precision were evaluated using radiographs from 15 scoliotic patients and a spine model in 24 poses. On in vivo radiographs, accuracy was within 2.8° for orientation and 2.4 mm for location; precision was within 2.3° for orientation and 2.1 mm for location. results were slightly better on model radiographs than on in vivo radiographs but without significance (p>0.05). The duration for user intervention was less than 2 min, and the computation time was within 3 min. Results indicated the method's reliability. It is a promising tool to determine 3-D spinal geometry with acceptable user interaction.
authors: Department of Electronic Engineering, Yunnan University, Kunming, Yunnan 650091, China. jhzhang_2006@yahoo.com.cn
authors: Junhua
authors: J
authors: Zhang
authors: Liang
authors: L
authors: Lv
authors: Xinling
authors: X
authors: Shi
authors: Yuanyuan
authors: Y
authors: Wang
authors: Fei
authors: F
authors: Guo
authors: Yufeng
authors: Y
authors: Zhang
authors: Hongjian
authors: H
authors: Li
mesh_terms: D000293:Adolescent; D000465:Algorithms; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D010363:Pattern Recognition, Automated / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012600:Scoliosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging