Validation of the template - geometric approach

Standard geometric parameters such as Volume V, surface area A_surf, centreline length L_CL and median diameter D_med along the centreline of the vessel were computed for each patient shape, averaged over the entire population and compared with the respective parameter measured on the final template shape. The deviations ∆Dev from the mean population values were calculated for x being one of the parameters (V, A_surf, L_CL, D_med) calculated on the template and x¯ being the respective population mean as (Eq. 4):

The overall deviation ∆Dev_total of the template from population means was calculated as the average of the deviations from each of the above mentioned parameters. A template shape yielding a low overall deviation ∆Dev_total from population mean values of below 5 % was considered to represent a good approximation of the mean shape.