Spoiling

Spoiling#

A repetition leaves transverse magnetisation behind, and the next one refocuses part of it. These two lessons measure what a spoiler gradient removes and what it does not.

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What it establishes

Gradient spoiling

The steady state a gradient spoiler leaves, against the signal of an ideally spoiled repetition, and why no spoiler area closes the gap.

RF spoiling

The quadratic phase increment that closes it, and the increments that leave the residual coherent.