I have some dwmri scans obtained on a Philips Achieva 3T. These scans were obtained with both partial fourier and multiband SENSE. I'm going to try to post all relevant info I can based on stuff I've found on the web for computing the epi readout time for topup:
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1) Relevant partial fourier info from dicom header and exam card:
(0018,9036) Partial Fourier Direction PHASE
(0018,9081) Partial Fourier YES
Halfscan yes
factor 0.755102
2) Relevant SENSE info from dicom header and exam card:
(0018,9078) Parallel Acquisition Technique SENSE
SENSE yes
P reduction (AP) 2.2
MultiBand SENSE yes
MultiBand Factor 2
MultiBand Shift 2
3) More info from exam card:
ACQ matrix M x P 96 x 93
EPI factor 43
WFS (pix) / BW (Hz) 13.243 / 32.8
Fast Imaging mode EPI
shot mode single-shot
Reconstruction matrix 96
4) Info from pulse sequence (we actually pulled up the pulse sequence and measured these things):
number of actual echos: 32
spacing between echos: ~0.714 ms
actual epi readout time (time from center of first echo to center of last echo): ~21 ms
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I'm not sure how to incorporate all this info into correctly calculating the epi readout time for topup. I've read different guides online but I keep getting different answers. I think SENSE is used with 96/2.2 = ~43 (epi factor?). Then the halfscan factor is used like 43*0.755102 = ~32 which is where the 32 echos come from. I'm not sure though since these numbers don't match up quite right.
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