precession

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Related to Free precession: precessional, Torque-free precession

precession

[-sesh′ən]
Etymology: L, praecedere, to go before
a comparatively slow gyration of the axis of a spinning body such that the axis traces out a cone, caused by the application of a torque. The magnetic moment of a nucleus with spin experiences such a torque when inclined at an angle to an applied magnetic field, resulting in precession at the Larmor frequency.

precession

An MRI term for the relatively slow gyration of the axis of a spinning body, which traces out a conical configuration. Precision is caused by the application of a torque which tends to change the direction of the rotation axis and is continuously directed at right angles to the plane of the torque. The magnetic moment of a nucleus with spin will experience such a torque when inclined at an angle to the magnetic field, resulting in precession at the Larmor frequency.

pre·ces·sion

(prē-sesh'ŭn)
The secondary spin of magnetic movements around the main magnetic field.
References in periodicals archive ?
The study of free precession has opened a totally new window on the estimation of toroidal MFs of magnetars.
On flow effects in balanced steady-state free precession imaging: pictorial description, parameter dependence, and clinical implications.
2] is simply shortened, in the higher energy case the shape of the FID can be dramatically modified because the transverse magnetization can increase during the free precession.
We also are able to accommodate both orthopedic and internal medicine referrals because the Ultra is able to perform advanced applications, such as Steady State Free Precession (SSFP), as well as vascular and MR Cholangiopancreatography (MRCP) abdominal imaging.
Interest of the steady state free precession (SSFP) sequence for 3D modeling of the whole fetus.
0 software expands the Ultra's clinical capabilities with the latest MRI pulse sequences, including: SuperFASE, Steady State Two Echoes (SS2E) for high-contrast imaging, which is similar to Steady State Free Precession (SSFP); Steady State T2 (SST2) for conducting heavily weighted T2 images; Sliding Slab for enhanced 3D TOF (time-of-flight) brain MR angiography images; Variable No Phase Wrap (NPW); Line Scan Diffusion to complement Single Shot Echo Planar Imaging (SS-EPI); and Swirl Encoding to reduce the flow and motion artifacts.
Bright-blood NCE MRV pulse sequences include time-of-flight (TOF) gradient recalled-echo (GRE) or spoiled gradient recalled (SPGR) sequences as well as steady state free precession (SSFP) sequences.