Figures & data
Figure 1. The spine fastened in a plastic tube (top left); the final phantom with fiducial markers attached to the outside of the tube (bottom left); CT image (top center); MR image (top right); and AP (bottom center) and lateral (bottom right) X-ray images of the phantom.
![Figure 1. The spine fastened in a plastic tube (top left); the final phantom with fiducial markers attached to the outside of the tube (bottom left); CT image (top center); MR image (top right); and AP (bottom center) and lateral (bottom right) X-ray images of the phantom.](/cms/asset/52eaf586-0664-417f-ad0d-4d6a43e14e9b/icsu_a_109751_f0001_b.jpg)
Figure 4. Reconstruction of 3D marker position. Due to the uncertainty of X-ray marker localization and X-ray setup calibration, the projection lines do not cross at the same point.
![Figure 4. Reconstruction of 3D marker position. Due to the uncertainty of X-ray marker localization and X-ray setup calibration, the projection lines do not cross at the same point.](/cms/asset/d5465e41-8973-45d2-9854-24cb673bd2ef/icsu_a_109751_f0004_b.jpg)
Table I. Expected RMS TREs for “gold standard” registration (in mm).