On 26/01/2010 18:43, "Guido Biele" <[log in to unmask]> wrote:
> Hello,
>
> I have collected data with an EPI sequence [Siemens MAGNETOM Trio (TIM
> System)] with following unwarping-relevant parameters:
> - echo spacing = .53ms
> - number of in plane lines in the reconstructed epi image = 64
> - acceleration factor = 2
> - number of in plane reference lines = 24
> [of course i also have the b0 field phase and magnitude images]
>
> I wonder if I have to calcualte the echo spacing / dwell time for unwarping in
> feat
> simply by deviding the echo spacing of the EPI sequence by the acceleration
> factor, or if I also need to take into account that the scanner also acquires
> reference lines.
Hi,
You should just need to divide the actual echo spacing by the acceleration
factor to get the effective echo spacing needed for distortion correction.
Dave
>
> I would apreciate any hint or comment!
>
> Thanks, Guido
>
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