Dear experts,
I’m using single-shell data to perform whole-brain tractography. I have tried three algorithm,SD_STREAM , iFOD2 and MSMT global tractography. But the streamline length got from global tractography is very short. I calculated the terminal map and the terminal of steamline diftrubuted throughout the brain.I think that’s not right.
The streamline obtained by golbal tractography algorithm and terminal map are shown in the figure below:
The tracks within a coronal slab of 2.5 mm and overlaid on b0 image.
Steamline obtained by global tractography was transformed to MNI space. Then the terminal map was calculated and overlaid on MNI T1 image.
The data was scanned on 3T scanner. There are 64 diffusion gradient directins with b-value=1000 and one unwighted volume. Voxel size is 2x2x3mm.
The scripts I used are as follows:
dwi2response dhollander dwi.mif wm_response_global.txt gm_response_global.txt csf_response_global.txt
tckglobal dwi.mif wm_response_global.txt -riso csf_response_global.txt -mask WM_mask.nii.gz -niter 1e9 -lmax 10 -length 1 -weight 0.1 -ppot 0.05 -cpot 0.5 -fod fod_global.mif -fiso fiso_global.mif tract_global.tck
For global tractography, I used WM mask and ditch the GM response according to ThijsDhollander’s answer and all the parameter are default.
Am I using the right parameters? Or do I need to adjust the parameters?
In addition, I also performed whole-brain tractography with iFOD2 algorithm. I used ACT and SIFT during tracking. The results are better than global tractography. Whether the terminal map results are incorrect is related to the absence of ACT? Can ACT be used for global tractography?
iFOD2 tractography command and results are as follow:
tckgen wm_fod.mif -algorithm iFOD2 -act 5TT_2nodif.mif -backtrack -crop_at_gmwmi -seed_random_per_voxel WM_mask.nii.gz 25 iFOD2.tck -output_seeds iFOD2_seeds
The tracks within a coronal slab of 2.5 mm and overlaid on b0 image.
Stay healthy and stay happy!
Many thanks!
Xiao