Registration of two-dimensional cardiac images to preprocedural three-dimensional images for interventional applications

Purpose: To evaluate the accuracy and efficiency of rigid-body registration of two-dimensional fast cine and real-time cardiac images to high-resolution and SNR three-dimensional preprocedural reference volumes for application during MRI-guided interventional procedures. Materials and Methods: Mutual information (MI) and correlation ratio (CR) similarity measures were evaluated. The dependence of registration accuracy and efficiency on different resolution and SNR parameters, and also on cardiac-phase differences was evaluated in a porcine model. Two-dimensional images were initially misoriented at distances (d) of 2-10 mm, and rotations of +/- 5 degrees about all axes. Registration error and computation time were evaluated, and performance was also assessed visually. Results: The maximum registration error using MI (< 2.7 mm and < 3.6 degrees) occurred for d = 10 mm, misrotation of +/- 5 degrees, and relative SNR = 1. The computation time was 15 seconds for MI and 10 seconds for CR. Conclusion: Registration accuracy was not highly dependent on the relative timing, within the cycle, between the two-dimensional and three-dimensional images. Registration using CR was faster than that using MI, although accuracy was marginally higher with MI.