Surface fitting approach to the correction of spatial intensity variations in MR images
Benoît M. Dawant, Alex P. Zijdenbos, Richard A. Margolin · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
Spatial intensity variations introduced by non-uniformity in the radio frequency (rf) coil of most MR scanners in clinical use preclude the selection of a single threshold for the separation of tissues across the entire image. Also, they increase the variance of the data, thus reducing the efficacy of numerical classifiers designed for the automatic segmentation of these images. In this paper, we present a new technique for the correction of spatial intensity variations. The methods require the labeling of a number of reference points across the image to which intensity surfaces are fitted. These surfaces are then utilized to correct the original images. Results obtained with phantom and patient data demonstrate the robustness of the approach and its impact on the classification results obtained with automatic classifiers.