phase encoding

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phase en·cod·ing

in magnetic resonance imaging, the technique of inducing a gradient in the magnetic field in the x or y axis to induce phase differences with location.
Synonym(s): gradient encoding

phase encoding

An MRI term for the process of locating an MR signal by altering the phase of spins in one dimension with a pulsed magnetic field gradient along that dimension before acquiring the signal. Because each signal component experiences a different phase-encoding gradient pulse, its exact spatial reconstruction can be specifically and precisely located by the Fourier transformation analysis. Spatial resolution is directly correlated to the number of phase-encoding levels (gradients) used.
References in periodicals archive ?
According to the literature [16-20], the effect of [B.sup.+.sub.1] encoding on the image quality and resolution as function of the variation in RF amplitude and nonuniformity in RF gradient field is comparable to that of [B.sub.0] gradient encoding. While [B.sup.+.sub.1] gradient encoding has shown to be perfectly feasible at lower [B.sub.0] fields (below about 1.5 Tesla), significant issues tend to arise at high static magnetic fields (3 Tesla and above), where RF fields transmitted through the patient during the image acquisition process invariably lead to significant RF field nonuniformities as result of complicated field-tissue interactions and wave phenomena [29-31].
In [B.sup.+.sub.1] gradient encoding (here, with rotating RF coil), a range of contrast is available, including the typical [T.sub.1]/[T.sub.2] relaxation times, diffusion, and chemical shift [34, 35].
A new [B.sub.0] gradient-free MRI technique based on [B.sup.+.sub.1] gradient encoding using the rotation of a RF coil ([B.sub.1]-RRFC) was described.