Serial FEM/XFEM-Based Update of Preoperative Brain Images Using Intraoperative MRI

Figure 6

Second patient case. (a) Sequence of five input iMR images rigidly registered to the first one. (1b) Whole-brain region extracted from (1a). (2b) Deformation of (1b) computed using FEM for brain shift modeling. (3b) Deformation of whole-brain region extracted from (2a) computed using FEM for 1st resection modeling. (3c) Masking of (3b) with whole-brain region segmented from the 3rd iMR image (3a). (4b) Deformation of whole-brain region extracted from (3a) computed using XFEM for 2nd resection modeling. (4c) Masking of (4b) with whole-brain region segmented from 4th iMR image (4a). (5b) Deformation of whole-brain region extracted from (4a) computed using XFEM for 3rd resection modeling. (5c) Masking of (5b) with whole-brain region segmented from 5th iMR image (5a). (d) Juxtaposition of Canny edges of images rigidly registered. The edges of the first (second) image of the pair under consideration are in green (red). (e) Ditto for (d) when images are nonrigidly registered.