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shimming-toolbox / shimming-toolbox-matlab

Code for performing real-time shimming using external MRI shim coils
GNU General Public License v3.0
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Bug in realtime_zshim.m #61

Open evaalonsoortiz opened 4 years ago

evaalonsoortiz commented 4 years ago

When going the route of fit B0 vs pressure first then compute the derivative we are re-normalizing values twice. First here: https://github.com/neuropoly/realtime_shimming/blob/a7690fba9cc4e7fca6c58ceda76dd7bf516a73c5/example/realtime_zshim.m#L219 Then here agin: https://github.com/neuropoly/realtime_shimming/blob/a7690fba9cc4e7fca6c58ceda76dd7bf516a73c5/example/realtime_zshim.m#L313

This leads to a discrepancy with the results where we first compute the gradient (Gz) then fit that with respect to pressure.

evaalonsoortiz commented 4 years ago

This issue has been addressed with #rt_issue61