A vascular assessment apparatus is disclosed. The apparatus is configured to receive a stenotic model having measurements of a coronary vessel tree of a subject, the stenotic model created from a set of medical images recorded before the subject underwent a stent procedure. The apparatus is also configured to receive a post-medical image of the coronary vessel tree of the subject after the stent has been placed into the coronary vessel tree and identify vascular features within the post medical image that correspond to vascular features that are provided among the set of medical images. The apparatus is further configured to modify geometrical information for the corresponding vascular features in the stenotic model to create an updated stenotic model from the identified vascular features of the post medical image and calculate an index indicative of vascular function, based, at least in part, on the updated stenotic model.