Description

Tested with the GUI when importing two different contexts:

• GE 3D Spiral; PCASL
• Siemens 3D GRASE; PASL

Import went fine (in this case), but it seems parameters from BIDS ASL sidecars in the GE subset bled over into the Siemens subset.

The 1.45 Labeling Duration you see was defined for the GE subset. It carried on over to the Siemens one (invalidating it because the Siemens is PASL, which shouldn't have LabelingDuration present).

Thankfully common fields to contexts (i.e. Arterial Spin Labeling Type) do not overwrite between contexts, regardless of whether they are present in the DICOM headers or not.

This issue seems to only occur for fields whose presence/absence is variable (i.e. BackgroundSuppressionPulseTime, LabelingDuration, BolusCutOffDelayTime, etc.)

check also #1279

Tasks

• Perform some minor BIDS validation when switching contexts. Remove incompatible fields from the previous context. Multiple scenarios of this exist, including:
  • PCASL -> PASL switches and vice versa
  • Subsets with background sup -> without bsup (and vice versa)

How to test

Run any two flavors of ASL with drastically different setups. Notice how parameters from the first flavor will bleed into the second.

Attachments

ExploreASL-Issue1264-MultiContextParsCarryOver.zip

Release notes

Nothing. It was not really a bug, just confusion about the exact function.