MRSI acquisition parameters

Could you please tell me why the FOV of MRSI is wider than VOI?

Will there be artifacts if the FOV and VOI are the same size?

Hi @Jason ,

In short, you want your FOV larger than the VOI. If it is the same size, then artifactual signal outside your VOI/FOV will be aliased into the middle of your FOV.

Slightly longer version:
If there is a VOI and an FOV, I’m going to assume that this MRSI sequence uses a magnetisation preparation module that includes localisation as well, something like PRESS, STEAM or sLASER. These are also known as single voxel sequences, but when used for MRSI, spatial encoding is included in the signal readout module. The purpose of this localised mag preparation is usually to only prepare signal from a region that doesn’t contain lipids (assuming brain here), which otherwise spread across the whole image due to the point-spread-function (PSF). You then image a larger region (by prescribing a larger FoV) to avoid aliasing any artifactual signal into your VOI region. The magnetisation preparation isn’t perfect so signal still arises from areas outside the VOI.

Hi wclarke,

I will try using it for acquisition parameters.