thank you ________________________________________ Von: Anastasia Yendiki [ayend...@nmr.mgh.harvard.edu] Gesendet: Sonntag, 12. Januar 2014 03:10 An: Roschinski, Benjamin Cc: freesurfer@nmr.mgh.harvard.edu; gerit.pf...@gmail.com Betreff: Re: b value for TRACULA
Hi Benjamin - The ball-and-stick model doesn't require b-values in the tens of thousands, that would be for DSI type acquisitions. a.y On Sat, 11 Jan 2014, Roschinski, Benjamin wrote: > Dear Anastasia, > > in the FS Tutorial/Running Freesurfer you say TRACULA uses bedpostX to fit > the ball-and-stick model to the DWI data. > So with TRACULA we use a high angular resolution diffusion imaging model and > you give the recommendation in "Introduction to diffusion MRI" to set the b > value for HARDI ~ 10,000 sec/mm² with a few of 100´s of gradient directions. > The b values in your published articles are much less than what you adviced > and you also used much less > gradient directions. > What does it mean? Why do you suggest a higher b value although you use a > much less one? > Is it because of the upper likelihood of motion effects and the longer scan > time or did I misunderstand the relationship between TRACULA and HARDI? > > kind regards > Benjamin > > AG Ehrlich > Medizinische Fakultät Carl Gustav Carus > TU Dresden > > The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
