dephasing


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de·phas·ing

(dē-fāz'ing),
In magnetic resonance imaging, following alignment by a radiofrequency pulse, the gradual loss of orientation of the magnetic atomic nuclei due to random molecular energy transfer or relaxation.

dephasing

An MRI term of art referring to the fanning out or loss of phase coherence of signals within the transverse plane.

de·phas·ing

(dē-fāz'ing)
magnetic resonance The gradual loss of orientation of the magnetic atomic nuclei due to random molecular energy transfer or relaxation following alignment by a radiofrequency pulse.
References in periodicals archive ?
This fellowship will address this issue using spectroscopy to determine the microscopic structure of the defect/s responsible for the quantum emission and to study the dephasing processes arising from the interaction of the quantum system with its local environment, and which limit the indistinguishability of the emitted photons.
The majority of flow gaps on 2D TOF MRV on the posterior aspect of superior sagittal and transverse sinuses were possibly associated with saturation of in-flow or intra-voxel dephasing rather than a true anatomic hypoplasia of the venous sinuses.
Miniaturizing the iron oxide particles to certain sizes in which each particle consists of a single magnetic domain with thermal energy high enough to overcome the energy barrier of magnetic flipping could generate local interactions with water protons that can induce proton dephasing and shorten transverse T2 relaxation.[76],[77] Thus, the aggravation of these iron oxide particles causes a reduced signal that is easily detected on the MRI T2 sequence, achieving a contrast effect.
It was the objectivisation or 'figuration' of some of these points into specific entities (such as technical objects) which progressively generated a 'dephasing' (borrowed from physics) of the different modes of thinking between, among others, technical and religious ones (Simondon 2012[1958]:221-245).
To assess stenosis, an SSFP gradient echo sequence will demonstrate the dephasing jet through the site of obstruction.
Several articles have considered beam quality in OPCPA systems [26, 27], mainly by examining the influences of the pump beam-profile and dephasing on OPA gain and signal beam quality.
Gonzalez-Vila, "Selective effects of forest fires on the structural domains of soil humic acids as shown by dipolar dephasing [sup.13]C NMR and graphical-statistical analysis of pyrolysis compounds," Journal of Soils and Sediments, vol.
In this section, we exemplify our discussion using probably the simplest model of decoherence, the pure dephasing model [10, 14].
For each voxel of the digital phantom, nuclear magnetic resonance (NMR) properties including equilibrium magnetization ([M.sub.0]), longitudinal relaxation time ([T.sub.1]), transverse relaxation time ([T.sup.*.sub.2]), and transverse relaxation time with extra dephasing effects (T2;) were defined [26].
The spin-lattice ([T.sub.1]) relaxation involves the transfer of energy between the spin system and the environment, and spin-spin relaxation ([T.sub.2]) processes involve the dephasing of nuclear spins, which are entropic processes [8].
Bird, "Recent experimental studies of electron dephasing in metal and semiconductor mesoscopic structures," Journal of Physics: Condensed Matter, vol.
Refocused pulses, usually 180[degrees], correct many sources of dephasing, making FSE imaging effective for minimising susceptibility artifact.