1. A non-transitory computer-readable medium including instructions executable by a processor to perform a method, the method comprising: generating a centerline model to parameterize a centerline of a tubular structure of a patient's anatomy, wherein generating the computed trajectory parameterizes centerline model comprises: computing a gradient vector field based on a three-dimensional voxel data set that includes voxels in image data for the tubular structure; computing a scalar derivative of each voxel in the gradient vector field to provide a derivative field that identifies a rate at which each voxel is changing direction; identifying a set of voxels residing on the centerline of the tubular structure based on an evaluation of the derivative field for each of the voxels; and storing in memory a centerline data set, corresponding to the centerline model, based on the identified set of voxels; computing a surface model of a tubular structure based on the centerline data set; acquiring an image data set for a portion of the tubular structure; and superimposing the surface model of the tubular structure onto a graphical representation of the portion of the tubular structure.