T2 Relaxation (Transverse or Spin–Spin Relaxation)

Abstract

The T2 process results in complete loss of transverse magnetization (M_xy) due to phase dispersion in the xy plane. The explanation is as follows: complex forces develop between dipoles moving in close proximity of each other, altering the local magnetic profiles. Thus, numerous sites develop slightly positive or negative deviations from the nominal strength of the main field B. Since the Larmor frequency follows the apparent value of B, there is a spread of the precession rates of the spins, around the nominal value. After a short time the microscopic spins (μ) move apart like a fan, and occupy random orientations (Fig. 11).