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spinicist / QUIT

A set of tools for processing Quantitative MR Images
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Residuals outside mask #9

Closed AndrewLawrence closed 6 years ago

AndrewLawrence commented 6 years ago

Residual images from qi tools (qidespot1hifi, qidespot1, qidespot2fm, qimcdespot) have a uniform single large value outside the provided mask. It is probably max float: ~3.4×10^38.

To view the residuals I have first been masking in FSL: fslmaths HIFI_residual.nii -mas Mask.nii HIFI_residual

Although this step is pretty simple, it would be more user friendly to output zeros or NaNs?

spinicist commented 6 years ago

I confirm this is a bug. It will need some investigation - the residual output is allocated in the same way as the parameter outputs, so it is not immediately clear why this is happening.

spinicist commented 6 years ago

Hello, This should be fixed in the development branch (commit d9bb191). The DESPOT residuals were being divided by the Proton Density image before writing, so they were of comparable magnitude. This was causing a 0/0 = Inf error outside the mask. I've swapped to simply writing out the unscaled residuals.