longitudinal relaxation

(redirected from spin-spin relaxation)
Also found in: Encyclopedia, Wikipedia.

lon·gi·tu·di·nal re·lax·a·tion

in nuclear magnetic resonance, the return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90°; varies in rate in different tissues, taking up to 15 s for water. See: TI.

longitudinal relaxation

An MRI term for the return of longitudinal magnetisation to equilibrium after excitation due to an exchange of energy between the nuclear spins and the lattice.

lon·gi·tu·di·nal re·lax·a·tion

(long'ji-tū'di-năl rē'lak-sā'shŭn)
magnetic resonance imaging The return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90°; varies in rate in different tissues, taking up to 15 seconds for water.
See: TI
References in periodicals archive ?
However, the spin-spin relaxation time, [T.sub.2], determined by the strength of dipolar interaction between neighboring [sup.19]F nuclei and proton nuclei, experiences more significant changes with every increase in concentration of [sup.19]F species.
The relaxation time [T.sub.2] reflects the number of water molecules with spin-spin relaxation time in the range of proton mobility.
The results of [T.sub.2]-weighted images showed the reduction of the spin-spin relaxation times ([T.sub.2]) from the lowest to highest concentrations, in which the signal intensity of the [T.sub.2]-weighted images decreased.
The spectra evaluated from echoes 1-10 in comparison with those from echoes 1-21 help to estimate the impact of spin-spin relaxation on the spectral shapes and intensities.
Table 2 summarises the results from spin-lattice relaxation time [T.sub.1] measurements and spin-spin relaxation time [T.sub.2]/[T.sub.1[rho]] measurements for [.sup.1.H].
By using NMR spin-spin relaxation techniques, it has been shown that the melt is not homogeneous in terms of molecular conformations.
The solid echo sequence provided a good approximation to the free induction decay, from which the proton spin-spin relaxation time ([T.sub.2]) was obtained (refs.
[T.sub.2i] : spin-spin relaxation time of each component
The polymer-carbon black interaction was evaluated by the measurements of spin-spin relaxation time in pulsed NMR spectroscopy.
On the other hand, the decline in spin-spin relaxation time beyond the maximum appears to be probably associated with the fact that the ionic mobility is again decreased because of the crystallinity of a low salt concentration PEO phase.
The Fraction of Mobile Lithium Ions and Their Spin-Spin Relaxation Times in (35)NBR-g-PEO/LiC[F.sub.3] S[O.sub.3] ([LiC[F.sub.3] S[O.sub.3]]/[EO] 0.1) Complexes.
The spin-spin relaxations [T.sub.2] were measured using the

Full browser ?