1. A method of invertibly deforming a diagnostic image surface mesh by automatically adjusting a radius of curvature of a deformation kernel, including: receiving user input regarding a start point p s for a contour to be deformed on a surface mesh overlaid on a diagnostic image; and adjusting a curvature of deformation to a distance between the start point p s and an end point p e , such that the curvature of deformation is adjusted in accordance with the distance between the start point p s and the end point p e ; wherein the start point p s and the end point p e are located on the contour to be deformed; wherein the curvature is defines by a radius, r, where: 
 r=λ∥p s −p e ∥, 
 where 
 λ>√{square root over (2)}·exp(−0.5)≈0.86, 
 where λ is a fixed scalar ratio.