Intercenter agreement of brain atrophy measurement in multiple sclerosis patients using manually-edited SIENA and SIENAX.
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.
Jasperse
Bas
B
Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. mms.jasperse@vumc.nl
Valsasina
Paola
P
Neacsu
Veronica
V
Knol
Dirk L
DL
De Stefano
Nicola
N
Enzinger
Christian
C
Smith
Stephen M
SM
Ropele
Stefan
S
Korteweg
Tijmen
T
Giorgio
Antonio
A
Anderson
Valerie
V
Polman
Chris H
CH
Filippi
Massimo
M
Miller
David H
DH
Rovaris
Marco
M
Barkhof
Frederik
F
Vrenken
Hugo
H
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