Hello FSLers,
I am trying to run eddy and am receiving the following error: "EDDY::: AcqPara::AcqPara: Unrealistic read-out time." And I am wondering if someone could help me correct my math when I am calculating my total readout time.
I am following the formula from: https://lcni.uoregon.edu/kb-articles/kb-0003
First, I calculated the Effective Echo Spacing (in sec) = 1/(BandwidthPerPixelPhaseEncode * MatrixSizePhase)
For BandwidthPerPixelPhaseEncode, I used dicom tag 0018,0095 = 1850 Hz (1/s); and for MatrixSizePhase, dicom tag 0018,1310 = 104
Thus, following the above formula, our Effective Echo Spacing = 0.0000052 sec
Then, to calculate the Total Readout Time: Readout Time = (MatrixSizePhase - 1)(Echo Spacing/2) *(Diving by 2 here due to GRAPPA)
Total readout time = (104-1)(0.0000052/2) = 0.00027 sec
I am not sure if dividing by 2 for the GRAPPA factor is what is making our readout time unrealistic for eddy input, but any help/suggestions for the calculation would be very much appreciated!
Thank you,
Hannah
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