mrikasper
commented
1 year ago Dear Ru,
Thank you for using PhysIO!
This is indeed the trickiest part when setting up Philips physiological logfile synchronization. Luckily, you only have to do it once per study, because the gradient time courses should only depend on sequence parameters (nSlices, TR, resolution, parallel imaging acceleration, angulation etc.), but are usually not subject-dependent.
A good starting point to understand the different parameters is this question in the FAQ. Basically, you will have to find a gradient direction, whose regularity reflects the onsets of slice and/or volume acquisition best and then set the thresholds in a way that you null local maxima (.zero threshold parameter), but keep the slice or volume peaks in the thresholded gradient time series (.slice and .vol threshold, respectively), as it is depicted in the middle panel of the Gradient Tresholding figure.
Let me know if this helps!
All the best, Lars
Ruwanmri
Hi,
I am trying to do physiological noise correction on Philips fmri and I want to use Scan/Physiolog time Synchronisation with gradient_log for the grad direction of Z. Could you please advise how to correctly set up the batch editor for Philips SCANPHYSIOLOGS. I get an error like below.
Error using tapas_physio_log No volume start events found, Decrease sync.vol or sync.slice after considering the Thresholding figureHere I chose my onset slice is 27 as we have 54 slices but I do not understand how to get the scan_timing.zero, slices and vol. Any help would be much appreciated.
Thank you.
Best regards, Ru