Post acquisition linearity correction for holospectral imaging in nuclear medicine

Conventional gamma cameras are designed for optimal performance only within a narrow energy window. To ensure adequate image quality, techniques using a wide energy spectrum, such as holospectral imaging (HI), require additional correction. A two-step post acquisition linearity correction algorithm has been developed for that purpose. First, the correction coefficients are evaluated based on the analysis of an ultrafast statistics flood image; second, a post acquisition correction is applied to the image of interest. The main idea of the algorithm is to map the original image matrix into a nonuniform pixel size matrix, through which the distorted image appears straight and uniform. The correction is a one-to-one spatial resampling of the original image using new center coordinates and a new area for each pixel of the image to be corrected. The computation of correction coefficients and their application on multiple frame images across a wide range of energy demonstrate the feasibility of extending the optimal performance of conventional cameras in terms of uniformity while maintaining spatial resolution. This allows scatter removal on post acquisition corrected images through holospectral imaging