Correct Use of Shim Pads
Although the MRI comes equipped with a set of shim pads that vary in thickness up to 12.5 mm, the thickest shim pads are never used in normal clinical practice. Unless you're scanning unusually thin anatomy, you can put away the 10 mm and 12.5 mm shims and forget about them. Use of the 7.5 mm shim will be rare.
In general, thinner shim pads yield better quality images, but of course, you must scan the appropriate anatomy.
Thinner shims are used for fatter hands
Fatter shims are used for thinner hands
This ensures that the center of the hand is in the center of the magnet.
If you find yourself needing to use thick shim pads, go back and verify that the temperature compensator has been properly adjusted for the ramp crossover in slice #10.
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