感应合和传统口内线圈的MR安全性
Agazi Samuel Tesfai1, Simon Reiss, Thomas Lottner
1From the Division of Medical Physics, Department of Diagnostic and Interventional Radiology, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
在MRI中,口内线圈 (IOC) 可能会导致射频诱导的加热. 两步安全评估发现,隔离IOC显著减少热点,确保更安全的MRI程序.
科学领域:
- 医疗成像医学成像
- 生物物理学的生物物理.
- 电气工程 电气工程
背景情况:
- 与口外线圈相比,口内线圈 (IOC) 提高了MRI信号与噪声的比率.
- 评估射频 (RF) 诱导的加热对于IOC安全至关重要.
- 现有的安全协议要求对新型线圈设计进行评估.
研究的目的:
- 通过评估射频诱导的加热,评估三种不同的口内线圈类型 (IFC,tLoop,tLoopRx) 的安全性.
- 为IOC引入和验证两步安全评估程序.
- 为了比较不同IOC类型和配置的温度升高.
主要方法:
- 一个两步的安全评估,包括电场测量/模拟用于热点识别,其次是MRI温度测量.
- 在1.5T和3T时测试三个IOC类型 (IFC,tLoop,tLoopRx) 在调和脱调状态.
- 应用高SAR和标准MRI协议,在幻影外围放置线圈.
主要成果:
- 电场测量显示调节的IOC中的热点在调节后减少了40倍以上.
- 在线圈平面与B0平行于幻影外围时,观察到最大的温度增加.
- 没有调节的IOC显示最大温度增加为1.3K (IFC),0.5K (tLoop) 和1.8K (tLoopRx).
- 模拟结果在同质幻影和解剖模型之间有所不同.
结论:
- 对调节的IOC存在RF诱导加热的风险.
- 适当的调节电路对于安全的IOC运行至关重要.
- 拟议的两步评估程序对于评估不同的IOC类型是有效的.
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