I have done the whole-brain FBA, and I want to do statistics with fixelcfestats. I have 3 groups (patient1, patient2, healthy controls), and I want to compare the FBA metrics among three groups. I need to perform the one-way ANOVA and post-hoc, I’ve noticed the option -ftests and -fonly of fixelcfestats, but I don’t know how to use them. Here is my design and contrast matrix, do they look fine?

I know my contrast matrix simply performs 6 t-tests, but I don’t know how to rewrite it to achieve one-way ANOVA and post-hoc. It would be very appreciated if you can give me some advice.

Hi, all
After learning some knowledge about GLM, I rewrote my contrast matrix.

As I mentioned before, I have two cohorts (patients and healthy controls, in which the patient group includes two subgroups).

I ran a two-sample T-test at first (patients vs. HCs), to investigate the different fixels between these 2 groups.
Design matrix: HCs patients sex age TIV (sex, age, and TIV demeaned)
Contrast matrix: C1: 1 -1 0 0 0
C2: -1 1 0 0 0

Then I ran an F-test and one-way ANOVA, respectively. (My goal is to investigate the among-group differences, but I was not sure whether to do F-test or ANOVA?)

For F-test:
Design matrix: HCs subgroup1 subgroup2 sex age TIV (sex, age, and TIV demeaned)
Contrast matrix: C1: 1 0 0 0 0 0
C2: 0 1 0 0 0 0
C2: 0 0 1 0 0 0
F matrix: [1 1 1]

For one-way ANOVA:
Design matrix: HCs subgroup1 subgroup2 sex age TIV (sex, age, and TIV demeaned)
Contrast matrix: C1: 1 -1 0 0 0 0
C2: 0 1 -1 0 0 0
F matrix: [1 1]

After that, I view the significant fixels in mrview. To my surprise, the significant fixels of the two-sample T-test are almost the same as those of the one-way ANOVA, why?

My goal is to investigate the among-group differences (among HCs, subgroup1, and subgroup2) and then extract the mean FBA metrics based on the significant fixel masks to do the post-hoc to investigate the between-group differences (HCs vs. subgroup1, HCs vs. subgroup2, and subgroup1 vs. subgroup2). To achieve my goal, which test should I do, an F-test or one-way ANOVA?