A new MRI rotation algorithm for the registration of temporal images

A system is being developed for automatic realignment of the patient in magnetic resonance imaging (MRI). Two images of the patient taken at different times are registered. Correction is made for any translation or rotation of the slices taken at a later date with respect to the master set (the scan taken on the first visit). Once the rotational movement is worked out, the slices are rotated through this angle and the registration parameters computed. This has motivated the development of a new technique for the rotation of MR images that is fast and fairly accurate. MR scans of the head are littered with edges, so that rotation algorithms using interpolation techniques based on the bilinear insertion procedure have the effect of blurring the image. The proposed method uses an interpolation technique that preserves the edges and was found to be superior in accuracy and speed to the bilinear interpolation rotation method