Multimodal matching by maximisation of mutual information and optical flow technique

Conformal radiotherapy is a therapeutic method requiring medical imaging, generally CT images to obtain Hounsfield number and electronic density data indications. The use of MRI simultaneously with CT imposes to deform CT images and superimpose them on MR images. The aim of this paper is to propose a nonrigid matching method between the two modalities (CT and MRI). The transformation model is defined by an optical flow registration algorithm, using mutual information as a similarity criterion.