 |
 |
6 dof maybe be good but it assumes that there are no eddy currents involved and that the B0 volumes can be registered by a rigid body transformation. cheers, andreas Am 20.04.12 17:20 schrieb "Stamatios Sotiropoulos" unter <[log in to unmask]>: >Hi Dustin, > >correct, apart from the SNR gain. It is sqrt(N), so in your case sqrt(6). > >Cheers >Stam > > >----- Original Message ----- >From: "Cunningham, Dustin" <[log in to unmask]> >To: <[log in to unmask]> >Sent: Friday, April 20, 2012 4:07 PM >Subject: [FSL] b=0 averaging > > >If I have say 6 b=0 images and I want to average them I would simply >coregister them (6 dof) then add and divide by 6, correct? > >...and this will give me a 6*sqrt(2) increase in SNR? > >Just want to make sure Im not missing anything. > >Dustin > > >________________________________________ >From: FSL - FMRIB's Software Library [[log in to unmask]] On Behalf Of >Andreas Bartsch [[log in to unmask]] >Sent: Thursday, April 19, 2012 5:47 PM >To: [log in to unmask] >Subject: Re: [FSL] DTI: Order of Eddy_correction vs. Unwarping > >Hi Pete, > >this is good! >Cheers, >Andreas > >PS: You don't really need 2.c, do you? > >Am 19.04.12 15:38 schrieb "Peter Fried" unter <[log in to unmask]>: > >>Hi FSL Community, >> >>Can someone confirm the appropriate order of pre-processing steps for DTI >>data? >> >>Specifically, does it matter whether the unwrapping (using the pre-stats >>option in FEAT) occurs before or after the eddy_correction? >> >>Here is what I have been doing and I just want to make sure it's correct: >> >>#1. Eddy Correction >>#2. Feat Pre-stats >> a. Unwarp >> b. bet >> c. Registration >>#3. dtifit >>#4. bedpostx >> >>Thanks! >> >>Cheers, >>Pete Fried >> >>Department of Anatomy & Neurobiology >>Boston University School of Medicine