title: Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study.
abstract: BACKGROUND
  Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge.
  
  
  METHODS
  To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.
  
  
  RESULTS
  Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.
  
  
  CONCLUSIONS
  Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Parviz
authors.initials: P
authors.lastname: Dolati
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Abdulkerim
authors.initials: A
authors.lastname: Gokoglu
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eichberg
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Zamani
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Golby
authors.affiliation: Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Ossama
authors.initials: O
authors.lastname: Al-Mefty
keywords: Blood vessels; cranial nerves; image segmentation; magnetic resonance imaging; neuronavigation; skull base neoplasms