Comparison of Cobb angles measured manually, calculated from 3-D spinal reconstruction, and estimated from torso asymmetry.
While scoliotic spinal deformity is traditionally measured by the Cobb angle, we seek to estimate scoliosis severity from the torso surface without X-ray radiation. Here, we measured the Cobb angle in three ways: by protractor from postero-anterior X-ray, by computer from a 3-D digitized model of the vertebral body line, and by neural-network estimation from indices of torso surface asymmetry. The estimates of the Cobb angle by computer and by neural network were equally accurate in 153 records from 52 patients (standard deviation of 6 degrees from the Cobb angle, r=0.93), showing that torso asymmetry reliably predicted spinal deformity. Further improvements in predictive accuracy may require estimation of other 3-D indices of spinal deformity besides the Cobb angle with its wide measurement variability.
McCaig Center for Joint Injury and Arthritis Research, University of Calgary, Alberta, Canada.
Jacob L
JL
Jaremko
Philippe
P
Poncet
Janet
J
Ronsky
James
J
Harder
Jean
J
Dansereau
Hubert
H
Labelle
Ronald F
RF
Zernicke
D000293:Adolescent; D000465:Algorithms; D002648:Child; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D007834:Lasers; D008954:Models, Biological; D016571:Neural Networks, Computer; D015588:Observer Variation; D010363:Pattern Recognition, Automated; D011859:Radiography; D015203:Reproducibility of Results; D012600:Scoliosis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity