Research Center Magnetic Resonance Bavaria (MRB), Am Hubland, 97074, Wuerzburg, Germany.
MAGMA. 2013 Apr;26(2):215-28. doi: 10.1007/s10334-012-0341-8. Epub 2012 Sep 27.
To construct an optimised, high-density receive array and a movement device to achieve dynamic imaging of the knee in orthopedic large animal models (e.g., minipigs) at 1.5 T.
A 13-channel RF receive array was constructed, and the crucial choice of the array element size (based on considerations like region of interest, geometry of the minipig's knee, achievable signal-to-noise ratio, applicability of parallel imaging, etc.) was determined using the Q factors of loops with different sizes. A special movement device was constructed to guide and produce a reproducible motion of the minipig's knee during acquisition.
The constructed array was electrically characterised and the reproducibility of the cyclic motion was validated. Snapshots of dynamic in vivo images taken at a temporal resolution (308 ms) are presented. Some of the fine internal structures within the minipig's knee, like cruciate ligaments, are traced in the snapshots.
This study is a step towards making dynamic imaging which can give additional information about joint injuries when static MRI is not able to give sufficient information, a routine clinical application. There, the combination of a high-density receive array and a movement device will be highly helpful in the diagnosis and therapy monitoring of knee injuries in the future.
构建优化的高密度接收阵列和运动装置，以实现 1.5T 下骨科大动物模型（如迷你猪）膝关节的动态成像。
构建了一个 13 通道射频接收阵列，并通过不同尺寸的线圈 Q 值确定了阵列元件尺寸的关键选择（考虑了感兴趣区域、迷你猪膝关节的几何形状、可实现的信噪比、并行成像的适用性等）。构建了一种特殊的运动装置，以在采集过程中引导和产生迷你猪膝关节的可重复运动。
对构建的阵列进行了电特性表征，并验证了循环运动的可重复性。呈现了在时间分辨率（308ms）下拍摄的动态体内图像的快照。在快照中可以追踪到迷你猪膝关节内的一些精细内部结构，如十字韧带。
这项研究是朝着将动态成像作为常规临床应用的一步迈进，该技术可以在静态 MRI 无法提供足够信息时提供有关关节损伤的附加信息。在这里，高密度接收阵列和运动装置的结合将在未来膝关节损伤的诊断和治疗监测中提供很大帮助。
