The smallest value of ICVF always larger than 0.1

[Shintai516]

Hello,

I was trying to fit the NODDI model with AMICO in tumor patients with edema.
In the results of the model fitting, I found that most of the voxels with edema were the same value in ICVF which was 0.1.
I've tried three different datasets and came-out with the same result.

This is the histogram of FIT_ICVF of three different datasets. The smallest value(zero excluded) was always equal to 0.1.

This is the same data but fitting with AMICO(left) and NODDI MATLAB toolbox(right).
Is there any clue or solution to fix this problem?

Thanks!

Cheers,
Shin Tai

[daducci]

Hi @Shintai516 ,

sorry for the delay. To create the linear operator AMICO discretizes the parameters like ICVF and OD. When we developed AMICO the aim was to reproduce the results of the original implementation and we set those parameters to given values (see

AMICO/amico/models.py

Line 483 in b599636

self.IC_VFs = np.linspace(0.1,0.99,12)

). You can modify those parameters using the set() function (

AMICO/amico/models.py

Line 488 in b599636

def set( self, dPar, dIso, IC_VFs, IC_ODs, isExvivo ):

) to suit your needs. Let us know if this solves your problem.

[Shintai516]

Thanks, @daducci
This helps a lot.
I will try to modify the parameter and run the function again.