Transmit/Receive Single Echo Acquisition MRI

描述（由申请人提供）：本EBRG提案的目标是开发发射/接收单回波采集（SEA）磁共振成像，以实现极高时间分辨率和任意曲面（仅在频率编码方向上为线性）的成像和流量测量。使用T/R阵列将消除对相位补偿脉冲的需要，这是我们之前使用仅接收阵列的结果中的限制。因此，这项新技术将更加强大，可以实现一致性阵列和3D成像。为了实现这一目标，我们将构建一个64通道，每通道30瓦的发射机。同时，我们将评估五种候选阵列元件设计，以获得穿透深度和去耦的最佳组合，然后构建64通道平面和圆柱形阵列。最后，我们将开发、测试和评估T/R SEA MRI的流动，使用相位对比和自旋标记方法，在常规和微流控模型上进行周期性和非周期性流动。如果成功，这项研究将开发出一种新的方法，能够在任意弯曲的切片上以前所未有的帧率（500帧/秒）进行磁共振成像。该方法将提供一种真正的“快照”流动成像方法，能够成像一次性事件，如磁共振弹性成像中正在研究的瞬态波，或狭窄血管模型中的非周期性流动。该阵列将适用于导管介入MRI和检测脑表面fMRI的快速反应。本研究特别感兴趣的是使用T/R SEA流量测量来表征微流控芯片实验室设备。目前正在研究在这些设备中创建混沌流动模式的方法，这可以将混合时间减少几个数量级，这对分子诊断和药物开发至关重要。本文提出的方法可以提供一种新的工具来表征这些器件中纯粹依赖于内源性对比度的混沌流，而不需要光学窗口或光反射的播种。

DESCRIPTION (provided by applicant): The objective of this EBRG proposal is to develop Transmit/Receive Single Echo Acquisition (SEA) magnetic resonance imaging to enable imaging and flow measurements at extremely high temporal resolutions and over arbitrarily curved planes (linear only in the frequency encoding direction). The use of a T/R array will remove the need for a phase compensation pulse, a limitation in our earlier results using receive-only arrays. Therefore this new technique will be far more robust, enabling conformable arrays and 3D imaging. To achieve this objective, we will build a 64 channel, 30 watt per channel transmitter. In parallel, we will evaluate five candidate array element designs for optimal combination of penetration depth and decoupling, and then construct 64 channel planar and cylindrical arrays. Finally, we will develop, test, and evaluate T/R SEA MRI of flow using phase contrast and spin-tagging methods on conventional and microfluidic phantoms with periodic and non-periodic flow. If successful, this study will have developed a new methodology capable of MR imaging at unprecedented frame rates (500 frames/second) over arbitrarily curved slices. The method will provide a true "snapshot" flow imaging method, capable of imaging one-time events such as transient waves being investigated for MR elastography or non-periodic flow such as in stenotic vessel models. The conformable arrays will be applicable in catheter based interventional MRI and detecting rapid responses in fMRI of the brain surface. Of particular interest in this study is the use of T/R SEA flow measurement for characterization of microfluidic lab-on-a-chip devices. Methods are being investigated to create chaotic flow patterns in these devices, which can decrease mixing times by several orders of magnitude, critical for molecular diagnostics and drug development. The methods proposed here could provide a new tool for characterization of chaotic flow in these devices relying purely on endogenous contrast, eliminating the need for optical windows or seeding for optical reflection.