T1rho and T2rho Mapping with Gradient Offset Independent Adiabatic Pulse Trains

Ovidiu C. Andronesi¹, Himanshu Bhat², Shreya Mukherjee¹, Peter Caravan¹, Bruce R. Rosen¹

T1 and T2 relaxation in the rotating frame (T1rho, T2rho) are sensitive to slow molecular dynamics on the ms time scale, relevant for interaction of water with important biological systems such as proteins, glycosaminoglycans and cell membranes. T1rho and T2rho have been used to investigate pathology of stroke, Alzheimers Disease, Parkinson Disease, liver cirrhosis and cartilage damage. Because T1rho and T2rho contrasts are created by the application of a long spin lock RF field, or by a train of adiabatic inversion pulses this results in sequences that have high specific absorption rate (SAR). Here we propose a pulse sequence based on low power gradient offset independent adiabatic pulses (GOIA-W(n,m))for decreasing SAR and performing slice selective T1rho and T2rho mapping.