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.