Simultaneous PET/MR imaging with a radio frequency-penetrable PET insert.
Simultaneous PET/MR imaging with a radio frequency-penetrable PET insert.
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DOI：
10.1002/mp.12031
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发表时间：
2017-01
期刊：
影响因子：
3.8
通讯作者：
Levin CS
中科院分区：
文献类型：
--
作者：
Grant AM;Lee BJ;Chang CM;Levin CS
大脑大小的射频（RF）可穿透PET插入物已被设计用于与MRI系统同时操作。该系统利用电光耦合和电池电源使PET插入物相对于MRI接地电浮动，允许RF信号通过形成PET环的模块之间的小间隙传输。这种设计便于使用内置体线圈进行RF传输，因此可以插入任何希望实现同步PET/MR成像的现有MR部位。PET探测器采用非磁性硅光电倍增管结合压缩传感信号多路复用方案和光纤将模拟PET探测器信号传输出MRI室，以进行解码、处理和图像重建。PET插入物首先在实验室工作台设置中构建和测试，其中成功采集了自定义分辨率体模的断层扫描图像。然后将PET插入物放置在3 T身体MRI系统内，并且在仅存在B 0场和来自不同MR成像序列的连续脉冲下采集断层扫描分辨率/对比度体模图像。在所有MR脉冲条件下，所得PET图像的对比度噪声比（CNR）相当：在MRI系统中采集的所有四幅PET图像中，每种棒类型的最大CNR相对差异百分比平均值为14.0± 7.7%。仅使用内置MR体线圈通过RF可穿透PET屏蔽成功采集MR图像，表明可以同时成像，而不会产生显著的相互干扰。这些结果表明，该技术有望成为昂贵的集成PET/MR扫描仪的替代品;与任何现有临床MRI系统兼容的PET插入物可以大大提高PET/MR的可用性、可及性和传播。
A brain sized radio-frequency (RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission, and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/MR imaging. The PET detectors employ non-magnetic silicon photomultipliers in conjunction with a compressed sensing signal multiplexing scheme, and optical fibers to transmit analog PET detector signals out of the MRI room for decoding, processing, and image reconstruction. The PET insert was first constructed and tested in a laboratory benchtop setting, where tomographic images of a custom resolution phantom were successfully acquired. The PET insert was then placed within a 3T body MRI system, and tomographic resolution/contrast phantom images were acquired both with only the B0 field present, and under continuous pulsing from different MR imaging sequences. The resulting PET images have comparable contrast-to-noise ratios (CNR) under all MR pulsing conditions: the maximum percent CNR relative difference for each rod type among all four PET images acquired in the MRI system has a mean of 14.0±7.7%. MR images were successfully acquired through the RF-penetrable PET shielding using only the built-in MR body coil, suggesting that simultaneous imaging is possible without significant mutual interference. These results show promise for this technology as an alternative to costly integrated PET/MR scanners; a PET insert that is compatible with any existing clinical MRI system could greatly increase the availability, accessibility, and dissemination of PET/MR.