title: Robustness of Automated Methods for Brain Volume Measurements across Different MRI Field Strengths.
abstract: BACKGROUND
  Pooling of multicenter brain imaging data is a trend in studies on ageing related brain diseases. This poses challenges to MR-based brain segmentation. The performance across different field strengths of three widely used automated methods for brain volume measurements was assessed in the present study.
  
  
  METHODS
  Ten subjects (mean age: 64 years) were scanned on 1.5T and 3T MRI on the same day. We determined robustness across field strength (i.e., whether measured volumes between 3T and 1.5T scans in the same subjects were similar) for SPM12, Freesurfer 5.3.0 and FSL 5.0.7. As a frame of reference, 3T MRI scans from 20 additional subjects (mean age: 71 years) were segmented manually to determine accuracy of the methods (i.e., whether measured volumes corresponded with expert-defined volumes).
  
  
  RESULTS
  Total brain volume (TBV) measurements were robust across field strength for Freesurfer and FSL (mean absolute difference as % of mean volume ≤ 1%), but less so for SPM (4%). Gray matter (GM) and white matter (WM) volume measurements were robust for Freesurfer (1%; 2%) and FSL (2%; 3%) but less so for SPM (5%; 4%). For intracranial volume (ICV), SPM was more robust (2%) than FSL (3%) and Freesurfer (9%). TBV measurements were accurate for SPM and FSL, but less so for Freesurfer. For GM volume, SPM was accurate, but accuracy was lower for Freesurfer and FSL. For WM volume, Freesurfer was accurate, but SPM and FSL were less accurate. For ICV, FSL was accurate, while SPM and Freesurfer were less accurate.
  
  
  CONCLUSIONS
  Brain volumes and ICV could be measured quite robustly in scans acquired at different field strengths, but performance of the methods varied depending on the assessed compartment (e.g., TBV or ICV). Selection of an appropriate method in multicenter brain imaging studies therefore depends on the compartment of interest.
authors: Department of Neurology and Neurosurgery, Brain Center Rudolph Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Rutger
authors: R
authors: Heinen
authors: Department of Neurology and Neurosurgery, Brain Center Rudolph Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Willem H
authors: WH
authors: Bouvy
authors: Image Sciences Institute, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Adrienne M
authors: AM
authors: Mendrik
authors: Image Sciences Institute, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Max A
authors: MA
authors: Viergever
authors: Department of Neurology and Neurosurgery, Brain Center Rudolph Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Geert Jan
authors: GJ
authors: Biessels
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Jeroen
authors: J
authors: de Bresser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000033:anatomy & histology* / Q000473:pathology; D066128:Gray Matter; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D059906:Neuroimaging; D009929:Organ Size; D015203:Reproducibility of Results; D066127:White Matter