1. A method comprising: accepting three-dimensional blood vessel imaging data; applying a sleeve-fitting algorithm to the three-dimensional blood vessel imaging data using a microprocessor, wherein the sleeve-fitting algorithm includes a garment-fitting algorithm and takes into account at least one of a branch geometry or geometry of an aneurysm; the sleeve-fitting algorithm further including at least one of: (a) extracting two or more sets of data, each data set defining a contour of a blood vessel sleeve at least partly based on the three-dimensional blood vessel imaging data, and interpolating data that represent one or more regions between two or more contours of a blood vessel sleeve; (b) applying a scale factor to the three-dimensional blood vessel imaging data: or (c) assigning a set of position coordinates to the three-dimensional blood vessel imaging data and assigning counterpart position coordinates to a blood vessel sleeve model to obtain blood vessel sleeve dimensions presenting a sleeve-fitting algorithm output in response to said applying the sleeve-fitting algorithm to the three-dimensional blood vessel data, wherein the sleeve-fitting algorithm output includes blood vessel sleeve dimensions.