Registration of orthogonal MR images

Analyses of heart wall motion, cavity volumes and myocardial mass in 3D are essential for understanding global function of the heart. One method for obtaining this information is to acquire two orthogonal series of 2D magnetic resonance (MR) images and reconstruct back to 3D using finite element analysis. Misregistration between the two series can occur due to patient motion. We have developed a program to register orthogonal series. For matching of two series, one series is fixed while the other one can be shifted and rotated with respect to the fired series. The matching process can be done manually or automatically. The manual matching is mouse driven and result is displayed in real time. The automatic method is based on minimizing the mean squared distance between the intersecting points of the contours of the moving series at the imaging plane of the fixed series and the contours of the fixed series. Results of validation tests show good registration for phantom and ex vivo data. The algorithm is also immune to small amount of noise in contours (<15%)