Simultaneous mapping of B0, B1 and T1 for the correction of CEST-MRI contrast

同时绘制 B0、B1 和 T1 以校正 CEST-MRI 对比度

• 批准号: 446320579
• 负责人: Dr. Patrick Schuenke
• 金额: --
• 依托单位: Fachbereich 8.1 - Biomedizinische Magnetresonanz
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/446320579?language=en
• 关键词: Simultaneous; mapping; B0; B1; T1

Chemical exchange saturation transfer (CEST) MRI is a relative new and versatile MR method. In CEST MRI, exogenous or endogenous compounds with exchangeable protons are selectively saturated. After the transfer of magnetization from the compound to surrounding water molecules, the compound can be detected indirectly as a reduction of the bulk water signal with increased sensitivity compared to a direct detection. Besides physiological parameters like metabolite concentrations and pH value, the detected CEST effect further depends on the T1 relaxation time of the examined object as well as on possible inhomogeneities of the static magnetic (B0) and/or RF excitation field (B1) of the MR system. Thus, quantitative mapping of these parameters is necessary for a subsequent pixel-wise correction of the acquired CEST data. Usually these three parameter maps are acquired using three separate MR pulse sequences, which comes along with a lot of effort for the implementation as well as essentially prolonged acquisition times. Therefore, the idea of this project is to develop a method for the simultaneous acquisition of all three parameter maps. The proposed method is based on a previously developed approach for the quantification of B0 and B1 that will be extended and combined with the utilization of a neuronal network to enable the additional mapping of T1. The method is compatible with conventional CEST pulse sequences, will provide 3D parameter maps of B0, B1 and T1 in less than two minutes and therefore contribute to the dissemination of unbiased CEST MRI in the clinical routine.

化学交换饱和转移（CEST）磁共振成像是一种较新的多功能磁共振成像方法。在CEST MRI中，具有可交换质子的外源性或内源性化合物被选择性地饱和。在磁化从化合物转移到周围的水分子之后，与直接检测相比，可以以增加的灵敏度间接检测化合物作为本体水信号的降低。除了代谢物浓度和pH值等生理参数外，检测到的CEST效应还取决于检查对象的T1弛豫时间以及MR系统的静态磁场（B 0）和/或RF激励场（B1）的可能不均匀性。因此，这些参数的定量映射对于所采集的CEST数据的后续逐像素校正是必要的。通常，使用三个单独的MR脉冲序列来采集这三个参数图，这伴随着沿着大量的实施工作以及实质上延长的采集时间。因此，本项目的想法是开发一种同时获取所有三个参数图的方法。所提出的方法是基于先前开发的方法，用于量化的B 0和B1，将扩展和结合利用的神经网络，使额外的映射T1。该方法与传统CEST脉冲序列兼容，将在不到两分钟的时间内提供B 0、B1和T1的3D参数图，因此有助于在临床常规中传播无偏CEST MRI。