Dear FADTTS users,

I am trying to use FADTTS with my data from DSIstudio, however I am having a problem with my diffusion data.

If I am correct I need a diffusion data matrix which will contain 1 value per subject/per tract. So, for instance a [75 x 64], 75tracts x 64subjects.

However, in my data, I do not have 1 value/per subject. I have different values for each "point" in the tract, and of course, different tracts.
So, I have a matrix for each subject of [4815 x 1335], which means, 4815 tracts and 1335 "points" along the tract. And these for every subject.

So, I am not sure how can I fit these into the diffusionfile that I need to enter to FADTTS. I was thinking to do one file for each point, but that will means I need 1335 files (one file/per "point" along the tract). Is there any better way?

Thank you for your time,
Myriam Oliver

Hi Myriam,

Thank you very much for using FADTTS. For your data set, you have 4815 tracts for each subject. If the order of the tracts is consistent across all subjects. You can reform you data structure. For example, if you have 100 subjects, you can form a matrix 1335 x 100 for each tract, then repeatedly apply FADTTS on each tract. Finally, you can get the global p value for each tract.


Please let me know if you have any other questions.

Best,
Chao

Thank you very much for your response!

I have another question.

At the Cdesign and BO, what "k" stands for?
Cdesign = k x mp
B0 = k x Lo

Sorry I could not find this information.
Is k refering to the number of diffusion properties? so in the example will bE 2 (refering to FA & MD?)

Thank you!!

k is the number of linear constraints in the test
m is the number of measures.