Silvia Mangia1, Timo Liimatainen2,
Igor Nestrasil3, Michael Garwood1, Paul Tuite3,
Dennis Sorce1, Shalom Michaeli1
1CMRR - Dept. of Radiology, University
of Minnesota, Minneapolis, MN, United States; 2Department of
Biotechnology and Molecular Medicine, A.I. Virtanen Institute for molecular
Medicine, University of Kuopio, Kuopio, Finland; 3Dept. of
Neurology, University of Minnesota, Minneapolis, MN, United States
Rotating
frame relaxation (T1rho and T2rho) were measured under a variety of RF pulses
(namely continuous-wave, and frequency swept pulses in the adiabatic and
subadiabatic regime) on twenty one Parkinson's disease (PD) subjects at 4T.
Results demonstrate that different RF pulses significantly modulate the
rotating frame relaxations in the substantia nigra (SN), providing the
opportunity to extract fundamental parameters of the system based on
theoretical modeling of the relaxation channels. The greatest sensitivity to
identify sub-regions of the SN was achieved by the so-called RAFF pulse,
which combines T1rho and T2rho relaxation mechanisms. Measurements from
ferritin samples were additionally performed.