Modified mec files

Submitted by ajevia on Thu, 07/16/2020 - 18:53


I have a few questions about the mec files for DIFF PREP.

I am using DIFF PREP on ex-vivo specimens that are not expected to move during the scan.
Is it possible to create a mec file that corrects only for eddy currents but not motion?

In the mec file, there are optimization and bracketing epsilons.
How are these epsilons used during the optimization process?

I've tried using the init_grd_step parameter, but could not seem to find values that made a significant change in the results.
In what cases would you use this parameter?
How do you set the values for this parameter?



Submitted by irfanogl on Tue, 08/11/2020 - 15:11


The parameter for that is called optimization_flags.
However, you do not need to edit a mec file for that. A mec file called "justeddy.mec" is already created and present in TORTOISE V3.2 distribution. you can directly use that one by providing the tag in the command line as "-c justeddy"

Hope this helps.

PS: However, do not forget that eddy-currents also cause translation along the phase-encoding direction. When you disable motion correction, this correction is disabled too.