Pantke Dennis, Mueller Florian, Reinartz Sebastian, Kiessling Fabian, Schulz Volkmar
Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.
Department of Diagnostic and Interventional Radiology, Uniklinik RWTH Aachen, Aachen, Germany.
Sci Rep. 2021 Feb 25;11(1):4529. doi: 10.1038/s41598-021-83821-w.
Changes in blood flow velocity play a crucial role during pathogenesis and progression of cardiovascular diseases. Imaging techniques capable of assessing flow velocities are clinically applied but are often not accurate, quantitative, and reliable enough to assess fine changes indicating the early onset of diseases and their conversion into a symptomatic stage. Magnetic particle imaging (MPI) promises to overcome these limitations. Existing MPI-based techniques perform velocity estimation on the reconstructed images, which restricts the measurable velocity range. Therefore, we developed a novel velocity quantification method by adapting the Doppler principle to MPI. Our method exploits the velocity-dependent frequency shift caused by a tracer motion-induced modulation of the emitted signal. The fundamental theory of our method is deduced and validated by simulations and measurements of moving phantoms. Overall, our method enables robust velocity quantification within milliseconds, with high accuracy, no radiation risk, no depth-dependency, and extended range compared to existing MPI-based velocity quantification techniques, highlighting the potential of our method as future medical application.
血流速度的变化在心血管疾病的发病机制和进展过程中起着至关重要的作用。能够评估血流速度的成像技术已在临床应用，但往往不够准确、定量和可靠，无法评估指示疾病早期发作及其转变为症状阶段的细微变化。磁粒子成像（MPI）有望克服这些局限性。现有的基于MPI的技术在重建图像上进行速度估计，这限制了可测量的速度范围。因此，我们通过将多普勒原理应用于MPI开发了一种新颖的速度量化方法。我们的方法利用了由示踪剂运动引起的发射信号调制所导致的与速度相关的频移。我们方法的基本理论通过对运动体模的模拟和测量进行了推导和验证。总体而言，与现有的基于MPI的速度量化技术相比，我们的方法能够在数毫秒内实现稳健的速度量化，具有高精度、无辐射风险、无深度依赖性且范围更广，突出了我们的方法作为未来医学应用的潜力。
