[Mristudio-users] Eddy currents interact with fat shift ?

[Dorian P.]

Dear experts,

Below is a picture from 3 DTI sequences during the same MRI acquisition on
a subject As you can see the fat shift didn't work properly, showing fat
rings. This ring seem to alternate for some slices, clearly visible in DWI
fitting error. Does this mean that fat shift problems interact with eddy
currents to produce alternating rings or is it just normal that fat ring
alternates between diffusion directions?

Second, this is somehow a naive and unrelated question. Given that I obtain
always 2+ datasets from each subject, isn't there a way to invert fat
suppression technique in the scanner such that one time I have a fat ring
showing as dark, but in the next dataset the same volume have the ring
brighter? This way the average of the fat ring will cancel out. Is there a
way to invert, not the position, but the values from the fat so that the
artifact would average theoretically to zero?

Thank you


Figure with fat ring problem. Lower lines are the DWI fitting error images:

[image: Immagine in linea 1]
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