The present invention relates to a medical imaging system (10) for planning an implantation of a cardiac implant (42), comprising: a receiving unit (12) for receiving a plurality of three-dimensional (3D) cardiac images (14, 14′) showing different conditions of a heart (32) during a cardiac cycle; a segmentation unit (22) for segmenting within the plurality of 3D cardiac images (14, 14′) a target implant region (38) and a locally adjacent region (40) that could interfere with the cardiac implant (42); a simulation unit (24) for simulating the implantation of the cardiac implant (42) within the target implant region (40) in at least two of the plurality of 3D cardiac images (14, 14′); a collision evaluation unit (26) for evaluating an overlap (46) of the simulated cardiac implant (42) with the segmented locally adjacent region (40) in at least two of the plurality of 3D cardiac images (14, 14′); and a feedback unit (28) for providing feedback information to a user concerning the evaluated overlap (46).