Intercenter differences in diffusion tensor MRI acquisition.
OBJECTIVE
To assess the effect on diffusion tensor (DT) magnetic resonance imaging (MRI) of acquiring data with different scanners.


METHODS
Forty-four healthy controls and 36 multiple sclerosis patients with low disability were studied using eight MR scanners with acquisition protocols that were as close to a standard protocol as possible. Between 7 and 13 subjects were studied in each center. Region-of-interest (ROI) and histogram-based analyses of fractional anisotropy (FA), axial (D(ax)), radial (D(rad)), and mean diffusivity (MD) were performed. The influence of variables such as the acquisition center and the control/patient group was determined with an analysis of variance (ANOVA) test.


RESULTS
The patient/control group explained approximately 25% of data variability of FA and D(rad) from midsagittal corpus callosum (CC) ROIs. Global FA, MD, and D(rad) in the white matter differentiated patients from controls, but with lower discriminatory power than for the CC. In the gray matter, MD discriminated patients from controls (30% of variability explained by group vs. 17% by center).


CONCLUSIONS
Significant variability of DT-MRI data can be attributed to the acquisition center, even when a standardized protocol is used. The use of appropriate segmentation methods and statistical models allows DT-derived metrics to differentiate patients from healthy controls.
Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Hospital San Raffaele, 20132 Milan, Italy.
Elisabetta
E
Pagani
Jochen G
JG
Hirsch
Petra J W
PJ
Pouwels
Mark A
MA
Horsfield
Elisabetta
E
Perego
Achim
A
Gass
Stefan D
SD
Roosendaal
Frederik
F
Barkhof
Federica
F
Agosta
Marco
M
Rovaris
Domenico
D
Caputo
Antonio
A
Giorgio
Jacqueline
J
Palace
Silvia
S
Marino
Nicola
N
De Stefano
Stefan
S
Ropele
Franz
F
Fazekas
Massimo
M
Filippi
D000328:Adult; D016022:Case-Control Studies; D003337:Corpus Callosum / Q000473:pathology*; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000473:pathology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry
D014867:Water