title: Measurement of cortical thickness in 3D brain MRI data: validation of the Laplacian method.
abstract: OBJECTIVE
  We aimed to determine the precision of the Laplacian approach for cortical thickness measurement due to changes in computational and acquisition parameters. We compared these results to two other methods widely used in clinical research using brain MRI data.
  
  
  METHODS
  Brain MRI scans were obtained in 10 healthy adults using three different sets of acquisition parameters. The first and the second acquisitions used different slice thickness but the same head position. The third scan was performed after head repositioning. We measured cerebral cortical thickness in all brain segmentations using three thickness methods: Laplacian, nearest distance, and the orthogonal projection.
  
  
  RESULTS
  The Laplacian method demonstrated the least variability with regard to the effect of interchange of boundaries, slice thickness, and repositioning of the head, compared with the other two methods.
  
  
  CONCLUSIONS
  The Laplacian method is the most precise and reliable tool for in vivo cortical thickness measurement using brain MRI data.
authors.affiliation: Department of Neurology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Haissam
authors.initials: H
authors.lastname: Haidar
authors.forename: Janet S
authors.initials: JS
authors.lastname: Soul
mesh_terms: D000328:Adult; D000465:Algorithms; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results