Quiz: MR Spectroscopy 4

Objectives: This talk outlines why shimming is required, what it does and gives an outline of the different approaches used to shim metabolites in both 1D and multidimensional MRS.

1. Biological tissue...*

Is diamagnetic
Is paramagnetic
Has magnetic susceptibility χ < 0
Both A and C

Jump to the relevant part of the video for question 1:

2. Shims are used to...*

Improve field homogeneity in the subject.
Reduce magnetic susceptibility in the subject.
Reduce field homogeneity in the magnet.
Reduce noise levels.

Jump to the relevant part of the video for question 2:

3. Why is B0 map shimming not always the best approach?*

The volume being shimmed is too big
The volume being shimmed is too small
It takes too long as you need at least 6 projections.
There is too much bad data in the map.

Jump to the relevant part of the video for question 3:

4. My shimming still has not improved the spectrum. This can be due to...*

Too many pixels in my B₀ shim map.
Inadequate water suppression.
Too few pixels in my B₀ shim map.
Phase wrapping.

Jump to the relevant part of the video for question 4: