ADIABATIC MAGNETIZATION PREPARATION PULSE FOR T2-CONTRAST AT 7 TESLA

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 7T的高分辨率MRI有可能在广泛的疾病的诊断和治疗方面提供巨大的改进 一系列神经疾病。高分辨率T2加权序列对评估细微构造很敏感 与许多此类疾病相关的异常[1]。不幸的是，传统的T2加权序列，例如 快速自旋回波(FSE)，利用一系列高翻转角度的Shinnar Le-Roux(SLR)[2]重聚焦脉冲，非常敏感 在7T时观察到严重的B1不均一性和SAR限制。我们提出了一种替代绝热磁化 准备(AMP)技术，在7T时获得B1不敏感的T2对比度。翻转角为0的BIR-4脉冲[3，4] 在段之间插入的延迟被用来引入T2衰减。AMP脉冲设计为在7T下使用，并进行了验证 用体模和活体实验。

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.