Same field map for fMRI and DWI distortion correction

1

Dear experts,

I am new to dealing with distortion correction by field map. In my dataset, one field map scan (two images with different echo times) was acquired before resting-state fMRI scan. My question is that the field map could be used for DWI distortion correction as well? My guess is that the field map reflect the B0 field inhomogeneity and should not take a big change during an MRI session. I tested this idea on one subject data and it seems the DWI distortion was corrected to some degree. However, I don’t know whether this is a commonly accepted way of acquiring field maps and doing distortion correction?

2

Hi @younghoo,

You can try comparing your field map correction with something like synB0-DisCo and see which methods looks better.

Best,
Steven

3

Thanks, Steven. I will test these field-map-free methods on my data and make some comparisons. I prefer these methods to using a field map scan, because standardizing the processing flow is easier without a field map in my opinion.