Accelerating Fully Phase-Encoded MRI Near Metal Using Multiband Radiofrequency Excitation
Accelerating Fully Phase-Encoded MRI Near Metal Using Multiband Radiofrequency Excitation
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DOI：
10.1002/mrm.26209
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发表时间：
2017-03-01
影响因子：
3.3
通讯作者：
Reeder, Scott B.
中科院分区：
文献类型：
--
作者：
Artz, Nathan S.;Wiens, Curtis N.;Reeder, Scott B.
目的：开发一种多波段射频（RF）激励策略，同时激励多个RF偏移，以加速金属prosthes.Methods附近的全相位编码成像：多波段RF激励的设计，并纳入光谱分辨全相位编码（SR-FPE）成像计划。将三频带（类似于6、0、6 kHz）采集与三个单独的单频带采集进行了比较，其中三个单独的单频带采集在相应的RF偏移下使用包含髋关节假体头部的体模。在体内的多波段数据与连续的光谱覆盖范围被收购在一个健康的志愿者的膝盖与头部的髋关节假体放置posteriorly和在一个志愿者与全膝关节假体implant.Results：幻影图像采集与三带激励基本上是相同的三个singleband激励的复合材料，但与加速因子为3。健康膝关节与相邻金属的体内多波段图像显示了膝关节解剖结构的良好描述。在体内的全膝关节置换术的图像被成功地收购，允许可视化的原生组织与远低于2D-FSE.Conclusions的信号丢失：FPE成像与多波段激励是可行的存在极端的非共振。这种方法可以减少扫描时间和/或增加非共振覆盖范围，从而能够在宽的非共振光谱上在金属假体附近进行体内FPE成像。(C)2016年国际医学磁共振学会
Purpose: To develop a multiband radiofrequency (RF) excitation strategy for simultaneous excitation of multiple RF offsets to accelerate fully phase-encoded imaging near metallic prostheses.Methods: Multiband RF excitation was designed and incorporated into a spectrally resolved fully phase-encoded (SR-FPE) imaging scheme. A triband (similar to 6, 0, 6 kHz) acquisition was compared with three separate single-band acquisitions at the corresponding RF offsets with a phantom containing the head of a hip prosthesis. In vivo multiband data with continuous spectral coverage were acquired in the knee of a healthy volunteer with the head of a hip prosthesis placed posteriorly and in a volunteer with a total knee prosthetic implant.Results: Phantom images acquired with triband excitation were essentially identical to the composite of three singleband excitations, but with an acceleration factor of three. In vivo multiband images of the healthy knee with adjacent metal demonstrated very good depiction of knee anatomy. In vivo images of the total knee replacement were successfully acquired, allowing visualization of native tissue with far less signal dropout than 2D-FSE.Conclusions: FPE imaging with multiband excitation is feasible in the presence of extreme off-resonance. This approach can reduce scan time and/or increase off-resonance coverage, enabling in vivo FPE imaging near metallic prostheses over a broad off-resonance spectrum. (C) 2016 International Society for Magnetic Resonance in Medicine