| 摘要 |
A method of examining a slice of a body by nuclear magnetic resonance in which a steady magnetic field, and a gradient field Gz along the same axis define the slice to be examined. A periodic magnetic field H1 at the Larmor frequency for the slice is applied in two distinct pulses 1, 2 each in conjunction with the gradient field. The total field integral of the two pulses is chosen to be sufficient to rotate spin vectors of nuclei in the field through an angle of pi /2 radians. Between the two pulses 1, 2, a further pulse 3 is applied in the absence of the gradient field Gz, which has a field integral sufficient to rotate the spin vectors through an angle of pi radians.
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