title: Intercenter agreement of brain atrophy measurement in multiple sclerosis patients using manually-edited SIENA and SIENAX.
abstract: OBJECTIVE
  To investigate intercenter agreement of brain volume (change) measurement in multiple sclerosis (MS) using structural image evaluation using normalization of atrophy (SIENA) and the cross-sectional version of SIENA (SIENAX) with additional manual editing to correct for inadequate brain extraction.
  
  
  METHODS
  Baseline and follow-up T1-weighted MR images of 20 MS patients were dispatched to five centers. Each center performed fully-automated and manually-edited analyses for SIENAX, yielding normalized brain volume (NBV), and SIENA, yielding percentage brain volume change (PBVC). Intercenter agreement was assessed with the concordance correlation coefficient (CCC).
  
  
  RESULTS
  Intercenter agreement was perfect for fully automated NBV and PBVC (both CCC = 1.0), and remained substantial upon manual editing (CCC = 0.94 for NBV, CCC = 0.95 for PBVC). Mean NBV values for each center decreased significantly after manual editing (overall mean NBV = 1605.3 cm(3) vs. 1651.1 cm(3) without manual editing; t = -4.58, P < 0.001). Total variance in PBVC decreased significantly by a factor of 1.8 after manual editing (sigma(2) = 2.82 before, and sigma(2) = 1.54 after manual editing, P < 0.05).
  
  
  CONCLUSIONS
  Substantial intercenter agreement was found for manually-edited SIENAX and SIENA, suggesting that measurements from multiple centers may be pooled. Manual editing reduces overestimation of NBV, and is likely to increase statistical power for PBVC.
authors: Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. mms.jasperse@vumc.nl
authors: Bas
authors: B
authors: Jasperse
authors: Paola
authors: P
authors: Valsasina
authors: Veronica
authors: V
authors: Neacsu
authors: Dirk L
authors: DL
authors: Knol
authors: Nicola
authors: N
authors: De Stefano
authors: Christian
authors: C
authors: Enzinger
authors: Stephen M
authors: SM
authors: Smith
authors: Stefan
authors: S
authors: Ropele
authors: Tijmen
authors: T
authors: Korteweg
authors: Antonio
authors: A
authors: Giorgio
authors: Valerie
authors: V
authors: Anderson
authors: Chris H
authors: CH
authors: Polman
authors: Massimo
authors: M
authors: Filippi
authors: David H
authors: DH
authors: Miller
authors: Marco
authors: M
authors: Rovaris
authors: Frederik
authors: F
authors: Barkhof
authors: Hugo
authors: H
authors: Vrenken
mesh_terms: D000328:Adult; D001284:Atrophy; D001331:Automation; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015233:Models, Statistical; D009103:Multiple Sclerosis / Q000473:pathology*; D010363:Pattern Recognition, Automated; D015203:Reproducibility of Results