PRELIMINARY-OBSERVATIONS OF TRANSVERSE RELAXATION RATES OBTAINED AT 3 TESLA FROM THE SUBSTANTIA-NIGRA OF ADULT NORMAL HUMAN BRAIN

The transverse relaxation rates R(2) and R(2)* were measured at 3 T in the substantia nigra of the midbrain of adult normal human controls, The relaxation rate arising from magnetic inhomogeneities, R(2)', was calculated from the relationship R(2)*=R(2)+R(2)'. No significant differences were found for any parameters between left and right side substantia nigral regions, however, a significant inverse correlation was found between R(2) and R(2)' (r=0.70, p=0.035), Water diffusion, in the presence of paramagnetic metal ions, may play a role in determining the relative contributions to reversible and irreversible transverse relaxation and may explain the inverse correlation demonstrated here.