Automatic estimation of midsagittal plane and AC-PC alignment on nonrigid registration

Identifying the anterior and posterior commissures as well as the midsagittal plane in magnetic resonance brain images is a critical first step in the normalization process underlying group studies. We present a fully automatic algorithm that locates these structures with high accuracy. Estimates of all three landmarks are achieved first with a nonrigid registration algorithm and further optimization is used to refine these estimates. Extensive validation experiments involving both simulated and real data sets demonstrate the accuracy and robustness of the proposed method.