Knowledge-based interpretation of mr brain images

Abstract

We have developed a method for fully automated segmentation and labeling of 17 neuroanatomic structures such as thalamus, caudate nucleus, ventricular system, etc. in magnetic resonance (MR) brain images. Our method is based on a hypothesize-and-verify principle and uses a genetic algorithm (GA) optimization technique to generate and evaluate image interpretation hypotheses in a feedback loop. Our method was trained in 20 individual Tl-weighted MR images. Observerdefined contours of neuroanatumic structures were used as a priori knowledge. The method's performance was validated in eight MR images by comparison to observer-defined independent standards. The GA-based image interpretation method correctly interpreted neuroanatomic structures in all images from the test set. Computer-identified and observer-defined neuroanatomic structure areas correlated very well (r = 0.99, y = 0.95x 2.1). Border positioning errors were small, with a root mean square (rms) border positioning error of 1.5 ±0.6 pixels. Our GAbased image interpretation method represents a novel approach to image interpretation and has been shown to produce accurate labeling of neuroanatomic structures in a set of MR brain images. © 1996 IEEE.