A FAST AND ACCURATE METHOD FOR REGISTRATION OF MR-IMAGES OF THE HEAD

This paper proposes a new fully automated technique that can be used f or the registration of medical images of the head. The method uses Che byshev polynomials in order to approximate and then minimize a novel m ultiresolutional, signal intensity independent disparity function, whi ch can generally be defined as the mean squared value of the mean weig hted ratio of two images. This function is explicitly computed for n C hebyshev points in a geometric transformation parameter interval [-A, +A] transformation units and is approximated using the Chebyshev polyn omials for all other points in the interval. For 3D T2-T1 weighted MR registration, 120 experiments with studies from ten patients were perf ormed and showed that n=4 Chebyshev points for A=18 transformation uni ts give mean rotational error 0.36 degrees and a mean translational er ror 0.36 mm. The different noise conditions did not affect the perform ance of the method. We conclude that the method is suitable for routin e clinical applications and that it has significant potential for futu re development and improvement. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.