Robustness assessment of model-based motion tracking using asynchronous biplane dynamic x-ray with forward and backward projected image registration

The study proposed a model-based tracking procedure integrating an asynchronous biplane imaging system, motion compensated frame interpolation and two different image registration strategies, namely forward-projection and backward-projection methods, for measuring 3-D dynamic joint motion. Successful registration rate, residual errors and run time of the method via the two image registration strategies in determining the tibiofemoral spatial poses were evaluated. The results showed that the forward projected 3-D/2-D image registration yielded more accurate pose estimation, greater successful registration rates and higher computational costs in comparison to those of the backward projected 3-D/3-D registration.