physimals / oxasl

Python based ASL pipeline based on oxford_asl
https://oxasl.readthedocs.io/
Apache License 2.0
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PWI generation for VEASL #24

Closed tomokell closed 7 months ago

tomokell commented 8 months ago

Allows the generation of a pseudo-perfusion weighted image (PWI) from vessel-encoded data by averaging over TIs (PLDs) and then taking the standard deviation across the vessel-encoding dimension, which should give an approximate PWI if the vessels have been reasonably efficiently encoded, as is generally the case. This PWI can then be used in e.g. registration steps, but does not affect the final quantitative CBF estimates. NB. the averaging across TIs is now also performed for multi-phase data, otherwise the estimated PWI from the FFT approach would be incorrect if all TIs were still included.

Martin/Michael: please do check you're happy with this approach or if there is a more elegant way to code it, but it works well in a couple of test cases I have.