A method includes accepting a plurality of MagneticResonance Imaging (MRI) data points of a cardiac chamber,acquired over multiple phases of at least one cardiac cycle. Asimulated surface of the cardiac chamber is constructed byprocessing the MRI data points. Measurements of a parameter,acquired at respective points on a surface of the cardiacchamber, are accepted from an intra-cardiac probe. Themeasurements are overlaid on the simulated surface constructedfrom the MRI data points, so as to produce a map of theparameter on the surface.
