T2(redirected from T-2)
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In magnetic resonance, the time for 63% of transverse relaxation to occur; the value is a function of magnetic field strength and the chemical environment of the hydrogen nucleus; for protons in fat and in water, in a 1.5T magnet, about 60 milliseconds and 250 milliseconds, respectively. A T2-weighted image will have a bright water signal.
The effective T2 relaxation time, shorter than T2 because of magnetic field inhomogeneities; the observed time constant of free induction decay. In gradient echo images, contrast depends on T2*, whereas in sequences with a 180° rephasing pulse, the contrast depends on T2.
Farlex Partner Medical Dictionary © Farlex 2012
T2An MRI term for the time constant at which phase coherence among spins oriented at an angle to the static magnetic field is lost due to interactions between the spins, resulting in a loss of transverse magnetisation and MRI signal.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
magnetic resonance The time for 63% of transverse relaxation to occur; the value is a function of magnetic field strength and the chemical environment of the hydrogen nucleus.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012