Fig. 1
From: Consistency of 3D femoral torsion measurement from MRI compared to CT gold standard
a 3D model of the proximal femur from CT data. b The same 3D model then 1a with the sphere fitted to the femoral head (green), the cross section at the narrowest point of the femoral neck (red) and the femoral neck axis (yellow), connecting the two centers. Both figures were created by the authors using the in-house developed surgical planning software CASPA (Balgrist CARD AG, Zurich, Switzerland)