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


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.


CONCLUSIONS
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. J.
Smolíková-Wachowiak
Renata
R
Imaging Research Laboratories, Robarts Research Institute, London, Ontario N6A 5K8, Canada.
Wachowiak
Mark P
MP
Fenster
Aaron
A
Drangova
Maria
M
D000465:Algorithms; D000818:Animals; D016477:Artifacts; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine; D023421:Models, Animal; D009206:Myocardium / Q000473:pathology*; D015642:Radiology, Interventional; D012680:Sensitivity and Specificity; D013552:Swine