One process, called T1, is responsible for the loss of resonance intensity following pulse excitation. The other process, called T2, characterizes the width or broadness of resonances.

Jun 29, 2020 · The process by which the magnetization in the xy plane decays away, over time, to its equilibrium value of zero, is known as T2 relaxation, transversal relaxation, relaxation on the xy plane, or In NMR, the net magnetization is detected in the xy plane, giving rise to the FID (Free Induction Decay).

T2 relaxation is the process by which the transverse components of magnetization (Mxy) decay or dephase. As originally described by Felix Bloch (1946), T2 relaxation is considered to follow first order kinetics, resulting in a simple exponential decay (like a radio-isotope) with time constant T2.

T2* can be considered an "observed" or "effective" T2, whereas the first T2 can be considered the "natural" or "true" T2 of the tissue being imaged. T2* is always less than or equal to T2. T2* results principally from inhomogeneities in the main magnetic field.

In physics, the spin–spin relaxation is the mechanism by which Mxy, the transverse component of the magnetization vector, exponentially decays towards its equilibrium value in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

Apr 25, 2022 · Because quantitative NMR measurements rely on resonance intensity, understanding the effects of T 1 relaxation is very important for obtaining accurate qNMR results. Therefore this subject is treated in greater depth in the Practical Aspects section of this module.

Aug 23, 2007 · • T2 relaxation – how long it takes for the spins to lose phase coherence, allowing the net magnetization (M 0) decay to 0 in the xy plane. – Spin flipping (+½ ↔-½) due to fluctuating local dipolar magnetic fields (inhomogeneity of the field) causes some spins to …

The major factor limiting determination of protein structure by NMR is the sensitivity as modulated by relaxation time. Hence determinationn of this parameter is a critical preliminary measurement to see if a protein together with a set of solution conditions (eg. temperature) are suitable for structural determination.

Transverse magnetization decay is described by an exponential curve, characterized by the time constant T2. After time T2, transverse magnetization has lost 63 % of its original value. T2 is tissue-specific and is always shorter than T1. Transverse relaxation is faster than longitudinal relaxation. T2 values are unrelated to field strength.

Transfer relaxation corresponds to the loss of phase coherence or randomization of spins in transverse direction (x-y) direction, which causes the loss of transfer magnetization. T2 refers to the time required for the transvers component Mxy to decay to 37% of initial value.