化学交换和转移 (CEST) 图像的简化评估:局部偏移频率和CEST效应
Daiki Chiba1, Yuki Kanazawa2, Tosiaki Miyati3
1Brain Attack Center Ota Memorial Hospital, 3-6-28 Okinogami, Fukuyama, Hiroshima, 7200825, Japan.
Radiological physics and technology
|October 28, 2023
概括
这项研究引入了一种用于评估化学交换和转移 (CEST) 成像的新幻影. 幻影有效地评估B0场的同质性和CEST效应,这对于优化MRI协议至关重要.
科学领域:
- 磁共振成像技术 磁共振成像技术
- 生物医学工程 生物医学工程
背景情况:
- 化学交换和转移 (CEST) 成像是一种强大的MRI技术.
- 准确评估CEST成像参数,如B0和B1领域的同质性,对于临床应用至关重要.
- 现有的幻影可能无法完全捕捉 in-vivo CEST成像条件的复杂性.
研究的目的:
- 开发和验证一种新的幻影,用于对临床CEST成像设置的全面评估.
- 评估幻影在评估B0和B1场的同质性,CEST对比度和后处理技术中的实用性.
- 通过基于幻影的分析来优化CEST成像协议.
主要方法:
- 构建了一个双切片幻影,其中包括用于局部偏移频率评估的网格部分和用于评估CEST效应的样本部分,其中含有不同度的白蛋白.
- 在3特斯拉MRI扫描仪上进行CEST成像,控制B1幅度 (1.2和1.9μT) 并有/没有B0校正.
- 对获取的图像进行了兴趣区域 (ROI) 分析,比较了不同B1幅度的B0校正和未经校正的CEST图像.
主要成果:
- 在B0校正的Z频谱中,在网格部分,曲线底部向0ppm的转移被证明.
- 在B1 = 1.9μT与1.2μT相比,观察到更广泛的Z频谱曲线形状.
- 对于白蛋白样本,MTRasym值在3.5ppm时,在B1 = 1.9μT与1.2μT时大约是两倍,这表明CEST效应增强.
结论:
- 开发的幻影能够成功地评估和优化B0不均性和CEST效应.
- 幻影作为一个有价值的工具,用于验证CEST成像序列和参数.
- 这种幻影使临床CEST成像协议的改进更加容易,从而提高了诊断准确度.
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