Magnetic resonance microwave absorption imaging: feasibility of signal detection.
Magnetic resonance microwave absorption imaging: feasibility of signal detection.
复制标题
磁共振微波吸收成像：信号检测的可行性。
DOI：
10.1118/1.3215533
复制
发表时间：
2009
期刊：
影响因子：
3.8
通讯作者：
Paulsen,KeithD
中科院分区：
文献类型：
--
作者：
Xie,Bin;Weaver,JohnB;Meaney,PaulM;Paulsen,KeithD
目的利用磁共振（MR）技术检测434 MHz脉冲微波能量局部吸收引起的微小位移，作为肿瘤检测的一种潜在方法。方法利用相位对比减影技术将热弹性膨胀引起的运动引起的相位变化与介质温升和MR扫描仪本身的相位偏移等对相位变化的贡献分开。进行了一组简单的实验，其中运动被约束为一维，其提供了对数据采集和运动提取过程的控制。具体而言，通过改变微波诱导运动的方向并在微波功率打开和关闭时在所有三个方向上对具有运动编码梯度的响应进行采样来分离MR检测到的运动信号。仅当运动编码与10 mm和4 mm空间尺度上微波诱导运动的垂直或水平方向平行时才发生。结论这些结果首次证明，与来自脉冲微波功率的吸收的热弹性膨胀相关联的运动可以用MR检测。
PurposeMagnetic resonance (MR) technique was used to detect small displacements induced by localized absorption of pulsed 434 MHz microwave power as a potential method for tumor detection.MethodsPhase contrast subtraction was used to separate the phase change due to motion from thermoelastic expansion from other contributions to phase variation such as the bulk temperature rise of the medium and phase offsets from the MR scanner itself. A simple set of experiments was performed where the motion was constrained to be one dimensional which provided controls on the data acquisition and motion extraction procedures. Specifically, the MR‐detected motion signal was isolated by altering the direction of the microwave‐induced motion and sampling the response with motion encoding gradients in all three directions when the microwave power was turned on and turned off.ResultsSuccessful signal detection, as evidenced by the recording of a systematic alternating (zigzag) phase pattern, occurred only when the motion encoding was in parallel with either the vertical or horizontal direction of the microwave‐induced motion on both 10 and 4 mm spatial scales.ConclusionsThese results demonstrate, for the first time, that motion associated with thermoelastic expansion from the absorption of pulsed microwave power can be detected with MR.