new pseudo-ct generation approach from magnetic resonance imaging using a local texture descriptor

Background: one of the challenges of pet/mri combined systems is to derive an attenuation map to correct the pet image. for that, the pseudo-ct image could be used to correct the attenuation. until now, most existing scientific researches construct this pseudo-ct image using the registration techniques. however, these techniques suffer from the local minima of the non-rigid deformation energy function which leads to unsatisfactory results.objective:we propose in this paper a new approach for the generation of a pseu-do-ct image from an mr image. materials and methods:this approach is based on a dense stereo matching concept, for that, we encode each pixel according to a shape related coordinates method, and we apply a local texture descriptor to put into correspondence pixels between mri patient and mri atlas images. the proposed approach was tested on a real mri data, and in order to show the effectiveness of the proposed local descriptor, it has been compared to three other local descriptors: sift, surf and daisy. also it was compared to registration method.results:the calculation of structural similarity (ssim) index and dice coefficients, between the pseudo-ct image and the corresponding real ct image show that the proposed stereo matching approach outperforms a registration one. conclusion:the use of dense matching with atlas promises good results in the creation of pseudo-ct. the proposed approach can be recommended as an alternative to registration techniques.