ADIABATIC MAGNETIZATION PREPARATION PULSE FOR T2-CONTRAST AT 7 TESLA

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. High-resolution MRI at 7T has the potential to provide tremendous improvement in the diagnosis and treatment of a wide range of neurological diseases. High-resolution T2-weighted sequences are sensitive for assessing subtle structural abnormalities associated with many of these diseases [1]. Unfortunately, conventional T2-weighted sequences, such as Fast Spin Echo (FSE), utilize a train of high flip-angle Shinnar Le-Roux (SLR) [2] refocusing pulses that are very susceptible to the severe B1 inhomogeneity and SAR limitations observed at 7T. We propose an alternative adiabatic magnetization preparation (AMP) technique to obtain B1-insensitive T2-contrast at 7T. A BIR-4 pulse [3,4] with a flip angle of 0¿ with delays inserted between segments is used to introduce T2 decay. An AMP pulse was designed for use at 7T and validated with phantom and in vivo experiments.