Detecting the onset of myocardial contraction for establishing inverse electro-mechanical coupling in XMR guided RF ablation

Radio-frequency (RF) ablation uses electrode-catheters to destroy abnormally conducting myocardial areas that lead to potentially lethal tachyarrhythmias. The procedure is normally guided with x-rays (2D), leading to errors in location and excessive radiation exposure. In order to provide pre- and intra-operative 3D MR guidance, we define a probabilistic measure of regional motion activation. Non-rigid registration of tagged MR sequences is used to track heart motion. Regional motion is also compared between different acquisitions, thus assisting in diagnosing arrhythmia, in follow up of treatment, and in determining whether ablation succeeded. We validate using an electro-mechanical model, synthetic tagged MRI, stress data on healthy volunteers, and one patient with tachyarrhythmia, before and after ablation.