1. A method for generating a pulmonary trunk model from 4D cardiac image data, comprising: receiving 4D cardiac image data comprising a plurality of frames, each frame comprising volumetric image data; detecting bounding boxes in the frames of the 4D cardiac image data; detecting anatomic landmarks in the frames of the 4D cardiac image data based on the detected bounding boxes; detecting ribs of a pulmonary artery in the frames of the 4D cardiac image data based on the detected anatomic landmarks; and generating a dynamic pulmonary trunk model by fitting a physiological pulmonary trunk model to the frames of the 4D cardiac image data based on the detected ribs and anatomic landmarks.