Questions Regarding Multi-PLD Data and M0 Settings

[Claire Lillian Illeck]

Hi Everyone,

I'm new to using ExploreASL and had a few questions regarding best practices, particularly for the ADNI dataset.

1. M0 estimation with multi-PLD data: 

    The ADNI pASL multi-PLD dataset does not include a separate M0 image. When using ExploreASL to generate the M0, is it appropriate to average all control images—even though they were acquired at different PLDs—or is it recommended to use only the control images from the lowest PLD?

2. Background suppression metadata:  

    Is there a standardized method to determine BackgroundSuppressionNumberPulses and BackgroundSuppressionPulseTime from DICOMs or sequence documentation? This dataset was acquired at multiple sites, and for scanners such as the Siemens Prisma, I’m having difficulty locating this information.

    

3. Use of M0_GMScaleFactor:  

    What is the recommended approach for setting the M0_GMScaleFactor when using a synthesized M0? I initially had high perfusion values and began adjusting the scale factor manually to bring values into a more realistic range, but I’d appreciate guidance on how this parameter should ideally be set.

    

Thank you very much for your help!

[Jan Petr]

Hi,

Sorry, I've noticed this only now - we don't check the groups too often. Let me know at j.petr(at)hzdr.de if you still need help.

best,

Jan