Investigation of MR Imaging With 64 Receiver Channels

64 个接收器通道的 MR 成像研究

• 批准号: 6762864
• 负责人: Steven M Wright
• 金额: $ 18.19万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6762864
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; magnetic resonance imaging; radiowave radiation

DESCRIPTION (provided by applicant): The objective of this project is to develop and characterize RF coil arrays for parallel MR Imaging at acceleration rates of up to 64 using a prototype 64 channel receiver system. Advances in gradient system and pulse sequence design have made dynamic MRI an important diagnostic tool. However, further increases in speed using conventional gradient based imaging appears limited by fundamental problems including gradient induced peripheral nerve stimulation and high RF power absorbtion rates. Parallel imaging, in which spatial localization is performed partially by the unique information contained in the reception patterns of an array of receiver coils, has become an important tool to reduce scan times without increasing gradient switching rates. These methods, known as SMASH, SENSE, SPACE-RIP and other variations, show great promise, but have only been explored to acceleration factors of 8, and 2 to 3 is more typical. This is partially due to the lack of availability of MRI systems with more than 8 receiver channels. In this project, planar and cylindrical array coils with 64 elements will be designed, fabricated and tested at the Magnetic Resonance Systems Lab on a 4.7 T scanner equipped with a 64 channel MRI receiver prototype that has been built and tested in the MRSL. Arrays will be characterized for SNR, artifact power and resolution at different levels of acceleration and imaging planes. An important feature of using the proposed large arrays is that the element size is on the order of the pixel, and differ from one another only by translation. Because of this, the point spread function of the array element itself can potentially be used to provide enhanced, or "superresolution". Superresolution techniques used in areas such as astronomical imaging and synthetic aperture radar will be investigated for their potential to provide improved spatial resolution, and sliding window techniques to provide improved spatial resolution with frame rates as high as one image per echo. both spatially and temporally, have the potential to provide improved resolution. The use of other resolution enhancement techniques including sliding window techniques will be investigated for imaging close to the array plane. It is expected that this project will advance our understanding of parallel MR imaging at very high frame rates, and provide researchers in this emerging field with data to test parallel imaging algorithms with more channels than previously available.

描述（由申请人提供）： 本项目的目标是开发和表征RF线圈阵列，用于使用原型64通道接收器系统在高达64的加速率下进行并行MR成像。梯度系统和脉冲序列设计的进步使动态MRI成为重要的诊断工具。然而，使用常规的基于梯度的成像的速度的进一步增加似乎受到包括梯度诱导的外周神经刺激和高RF功率吸收率的基本问题的限制。并行成像，其中空间定位部分地由包含在接收器线圈阵列的接收模式中的唯一信息执行，已经成为减少扫描时间而不增加梯度切换速率的重要工具。这些方法被称为SMASH，SENSE，SPACE-RIP和其他变体，显示出很大的前景，但仅探索了8的加速因子，2到3是更典型的。这部分是由于缺少具有8个以上接收器通道的MRI系统。 在本项目中，将在磁共振系统实验室设计、制造和测试具有64个元件的平面和圆柱形阵列线圈，该实验室配备了在MRSL中构建和测试的64通道MRI接收器原型的4.7 T扫描仪。阵列将在不同水平的加速度和成像平面下表征SNR、伪影功率和分辨率。使用所提出的大型阵列的一个重要特征是，元素大小是像素的数量级，并且彼此之间的差异仅在于平移。正因为如此，阵列元件本身的点扩散函数可以潜在地用于提供增强的或“超分辨率”。将研究在天文成像和合成孔径雷达等领域使用的超分辨率技术在提高空间分辨率方面的潜力，并研究滑动窗口技术在提高空间分辨率方面的潜力，其帧率高达每回波一幅图像。在空间上和时间上都具有提供改进的分辨率的潜力。使用其他分辨率增强技术，包括滑动窗口技术将被调查成像接近阵列平面。 预计该项目将推进我们对非常高帧率下并行MR成像的理解，并为这一新兴领域的研究人员提供数据，以测试具有比以前更多通道的并行成像算法。