There are quite a few papers that look at inter- and intra- site variance in DTI. For instance, take a look at:
Walker L, Curry M, Nayak A, Lange N, Pierpaoli C; and the Brain Development Cooperative Group. A Framework for the Analysis of Phantom Data in Multicenter Diffusion Tensor Imaging Studies, Hum Brain Mapp. 2012 [Epub ahead of print]
Gouttard S, Styner M, Prastawa M, Piven J, Gerig G. (2008): Assessment of reliability of multi-site neuroimaging via traveling phantom study. Med Image Comput Comput Assist Interv 11(Pt 2):263-70.
Pagani E, Hirsch JG, Pouwels PJ, Horsfield MA, Perego E, Gass A, Roosendaal SD, Barkhof F, Agosta F, Rovaris M and others. (2010): Intercenter differences in diffusion tensor MRI acquisition. J Magn Reson Imaging 31(6):1458-68.
Vollmar C, O'Muircheartaigh J, Barker GJ, Symms MR, Thompson P, Kumari V, Duncan JS, Richardson MP, Koepp MJ. (2010): Identical, but not the same: intra-site and inter-site reproducibility of fractional anisotropy measures on two 3.0T scanners. Neuroimage 51(4):1384-94.
Zhu T, Hu R, Qiu X, Taylor M, Tso Y, Yiannoutsos C, Navia B, Mori S, Ekholm S, Schifitto G and others. (2011): Quantification of accuracy and precision of multi-center DTI measurements: a diffusion phantom and human brain study. Neuroimage 56(3):1398-411.
While not all of these address specifically scanner manufacturer differences, they highlight important issues to consider when combining data from multiple imaging centers, even if the protocol is maintained exactly the same at all centers.
In our experiences there are distinct differences between data acquired on GE and Siemens; for instance, the 2 manufacturers have a different direction for the EPI blips, which results in opposite direction EPI distortions (expansion/contraction).
Hope this helps.
Lindsay.
________________________________________
From: Michael Harms [[log in to unmask]]
Sent: June 19, 2012 11:05 AM
To: [log in to unmask]
Subject: Re: [FSL] differnet MRI scanner
Depending on how the protocols were set up, there could be a lot of
differences -- b-values, direction and number of b-vectors, TR, TE,
voxel sizes, etc, etc. Were all those matched across scanners?
cheers,
-MH
On Tue, 2012-06-19 at 22:28 +0800, Peng Syu-Jyun wrote:
> Dear exports
>
> I have three sets DTI data that scan in different MRI scanners of all
> control subjects, include 1.5 T GE, 1.5 T Siemens and 1.5 T Philips
> scanner.
>
> I have 20 normal subjects, so total 60 sets DTI data.
>
> Each subjects have three sets DTI obtained in three different MRI
> scanners.
>
> What differences between the three sets DTI data of subjects?
>
> Could the MRI regarded as the smae in differnet MRI scanner (magnetic
> field are all 1.5 T)?
>
> Have any related paper?
>
> Best regards,
>
> Syu-Jyun
>
>
>
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