Strange fiber structure

Hi community,
I obtained some results about connection of ROIs (FFA), but I have two doubts: Fig.1(as following) Fiber count of ROIs (FFA) connection is very little. Is this normal? Fig.2(as following) Fiber structure is strange. How can I eliminate such fiber? Generating the fiber with parameters as following:
tckgen WM_FODs.mif 1M.tck -act 5TT.mif -backtrack -crop_at_gmwmi -seed_dynamic WM_FODs.mif -maxlength 250 -select 1M -cutoff 0.06
Fig.1

Fig.2

Hi @jiangjiane,
I can not see your figures.Did you upload them?
I’m very interested in your second question. What does the ‘strange structure’ mean? Are there some loops? or too winding?
Look forward to see your figures.
Best,
Zonglei