Method for determining a parameter which is indicative for the position and apposition of a tubular member, such as a stent graft, inserted in a lumen of an anatomical vessel or duct of a patient

Method for determining an apposition parameter which is indicative for the position and apposition of a tubular member, such as a stent graft, inserted in a lumen of an anatomical vessel or duct of a patient, wherein the method comprises the steps of: - providing a numerical three-dimensional patient model of at least a part of the vessel of the patient including the tubular member; - determining at least one vessel morphology parameter from the patient model, which parameter is indicative for the anatomy of a predetermined part of the vessel at or near the tubular member in said vessel with respect to said patient model; - determining at least one tubular member positional parameter from the patient model, which parameter is indicative for the position of a predetermined part of the tubular member in the patient model; - calculating, on the basis of the determined vessel morphology parameter and tubular member positional parameter, the relative position of the tubular member with respect to the vessel as the apposition parameter.