Hello
We are using dcm2niix ("ConversionSoftwareVersion": "v1.0.20220720") to convert multidelay PCASL data and create the associated json file.
The output json file has 2 fields labeled "ArterialSpinLabelingType", the first with the correct "PCASL" value and a second with "PASL" as the value which ends up overwriting the first when the file is later edited. This is an easy fix on our end so it's not a huge problem.
Also the field "PostLabelDelay" (which I think should be PostLabelingDelay maybe?) has a single incorrect value that doesn't match any of the actual delays. There are some other fields that ASLPrep thinks are supposed to be in there, but I don't know how "standard" they are, and again this is easily fixed after the fact.
Thank you
j
Note that the ASL information depends a lot of vendor (GE,
Siemens, Philips) and the software model (e.g. Siemens VE11 is very
different from XA30). The first thing I would strongly recommend is
to use the latest stable release (v1.0.20241211) - with the
adoption of enhanced DICOM and the ratification of the ASL BIDS
specification, there were a lot of changes in the intervening 29
months In particular, it is unfortunate that the BIDS specification
renamed some of the tags populated by dcm2niix, breaking backward
compatibility.
https://github.com/rordenlab/dcm2niix/re...
I would also suggest you try the ExploreASL wrapper for dcm2niix,
from the team that helped create the BIDS specification. While they
use dcm2niix (with its permissive license), their code uses an
institutional license that prevents me from understanding some of
the sequence details it extracts. Therefore, it is likely to
provide a more thorough solution
https://github.com/ExploreASL/ExploreASL
For most vendors and models, the DICOM data is underspecified
with regards to the desired fields, and will require some manual
intervention. The research collaboration manager (if you use
Siemens) or clinical scientist (for Philips) affiliated with your
center can help.
If you can share the dataset where dcm2niix assumes "PASL" when it
should be "PCASL", send a link to my institutional email:
https://sc.edu/study/colleges_schools/ar...
and I can try to do better.