ASLprep alignment of anatomical and functional data

Hello,

Summary of what happened

We have ran ASLprep (v.0.7.2) on our data.

Command used (and if a helper script was used, a link to the helper script or the command generated):

aslprep \
    neurodesktop-storage/Agueda/BIDS \
    neurodesktop-storage/Agueda/BIDS/derivatives/aslprep \
    participant \
    --participant-label sub-897\
    --force-bbr \
    --basil \
    --ignore t2w \
    --fs-subjects-dir /Users/heartybrain/neurodesktop-storage/heartybrain/BIDS/derivatives/freesurfer/sourcedata/freesurfer_pre/sourcedata \
    --bids-filter-file neurodesktop-storage/heartybrain/BIDS/BIDS_filter_file.json \
    --fs-license-file neurodesktop-storage/heartybrain/BIDS/license.txt \
    -vv \
    -w neurodesktop-storage/heartybrain/BIDS

When inspecting outputs we found out that alignment between ASL and anatomical data was not perfect for all participants, example below:

When decided then to rerun one participant to check if it was an error of preexisting freesurfer outputs, or because of using --force-bbr, however it still did not look perfect.

Command used (and if a helper script was used, a link to the helper script or the command generated):

aslprep \
    neurodesktop-storage/Agueda/BIDS \
    neurodesktop-storage/Agueda/BIDS/derivatives/aslprep \
    participant \
    --participant-label sub-897\
    --basil \
    --fs-no-reconall \
    --ignore t2w \
    --bids-filter-file neurodesktop-storage/heartybrain/BIDS/BIDS_filter_file.json \
    --fs-license-file neurodesktop-storage/heartybrain/BIDS/license.txt \
    -vv \
    -w neurodesktop-storage/heartybrain/BIDS

Results below:

Could anyone guide us into what it may be happening.
Thanks in advance!

Version:

0.7.2

Environment (Docker, Singularity / Apptainer, custom installation):

Docker