Rapid Field-Cycling Relaxometric Imaging Using Fast Spin-Echo

Peter J. Ross¹, Lionel M. Broche¹, Kerrin J. Pine¹, David J. Lurie¹

Fast Field-Cycling (FFC) adds a new dimension to MRI by rapidly switching B₀ between levels during a pulse sequence. In this way it is possible to observe the variation of tissue T₁ with field strength. Relaxometric FFC imaging collects data for T₁ images at a range of field strengths, but is inherently time-consuming. We have greatly increased the speed of acquisition by collecting only one inversion-recovery image per field and by implementing an FFC Fast Spin-Echo sequence. Typical acquisition time is 30 min for a set of T₁ images at 22 field strengths, making volunteer or clinical studies feasible.