Abstract
Resolution Enhanced TOSSI is a new MRI pulse sequence for the generation of rapid T2 contrast with high spatial resolution. TOSSI provides T2 contrast by using non-equally spaced inversion pulses throughout a bSSFP acquisition. In RE-TOSSI, these energy and time intensive adiabatic inversion pulses and associated magnetization preparation are removed from TOSSI after acquisition of the data around the center of k-space. Magnetization evolution simulations demonstrate T2 contrast in TOSSI as well as reduction in the widening of the point spread function width (by up to a factor of 4) to a near ideal case for RE-TOSSI. Phantom experimentation is used to characterize and compare the contrast and spatial resolution properties of TOSSI, RE-TOSSI, bSSFP, HASTE and TSE and to optimize the fraction of k-space acquired using TOSSI. Comparison images in the abdomen and brain demonstrate similar contrast and improved spatial resolution in RE-TOSSI compared to TOSSI. Comparison bSSFP, HASTE and TSE images are provided. RE-TOSSI is capable of providing high spatial resolution T2-weighted images in 1 second or less per image.
