在二维梯度回声双角度B 1 +映射上通过切片脱相的效果和校正
Gabriela Belsley1, Damian J Tyler1, Matthew D Robson1,2
1Oxford Centre for Clinical Magnetic Resonance Research, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
Magnetic resonance in medicine
|December 29, 2023
概括
切片依赖的B0变化显著混2D双角度B1+地图. 为这些B0不均性进行校正可以提高B1+和T1映射的准确性,这对于研究应用至关重要.
科学领域:
- 磁共振成像技术 磁共振成像技术
- 量化MRI是指数量化的MRI.
- 生物物理学的生物物理.
背景情况:
- 准确的B1+场映射对于像T1映射这样的定量MRI技术至关重要.
- 现有的使用梯度回声信号的二维双角度方法容易受到B0变化的影响.
研究的目的:
- 为了证明B0变化和切片形状效应是2D双角度B1+映射中的主要混因素.
- 引入和验证这些混因素的纠正方法.
主要方法:
- 布洛克模拟的2D梯度回声信号整合在切片,结合非线性B0变化.
- 非线性最小正方形适合与实验和模拟的梯度回声信号比相匹配.
- 在3T时通过幻影和体内研究的验证.
主要成果:
- 沿切片方向的B0变化导致B1+因子每10Hz/cm的误差约为3.8%.
- 拟议的校正减少了虚拟研究中的B1+平方根平均误差,从6.4%降至2.6%.
- 在活体T1地图显示,在应用更正的B1+地图后,切片梯度减少.
结论:
- 切片变化的B0同质性显著影响2D双角度B1+地图的准确性.
- 考虑B0变化对于准确的激发翻转角度确定至关重要.
- 这种纠正对于依赖精确定量MRI的研究至关重要,例如破坏的梯度召回回声T1映射.
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