Near-contiguous spin echo imaging using matched-phase RF and its application in velocity-selective arterial spin labeling.
Near-contiguous spin echo imaging using matched-phase RF and its application in velocity-selective arterial spin labeling.
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使用匹配的镜头RF及其在速度选择性动脉自旋标记中的应用近连接自旋回波成像。
DOI：
10.1002/mrm.24866
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发表时间：
2014-06
影响因子：
3.3
通讯作者：
Zaharchuk, Greg
中科院分区：
文献类型：
--
作者：
Zun, Zungho;Hargreaves, Brian A.;Pauly, John;Zaharchuk, Greg
多层螺旋成像中的最小切片间距受到切片间串扰的限制，这是由于不完美的切片轮廓造成的。本研究试图使用匹配相位RF脉冲来最小化切片间距，并展示其在使用速度选择性动脉自旋标记的脑血流成像中的应用。采用Shinnar-Le Roux算法设计了90°-180°自旋回波匹配射频对，以改善纵向磁化比横向磁化对产生片间串扰更重要的条带分布。在模拟和测量中，比较了匹配相位射频脉冲和基于SINC的射频脉冲的横向和纵向切片分布。用射频脉冲对正常志愿者进行速度选择性动脉自旋标记，计算脑血流时间序列的标准差，以检验ASL信号的稳定性。利用所设计的匹配相位射频，在不降低信噪比的情况下，实现了纵向切片轮廓的锐化。在速度选择性动脉自旋标记成像中，使用匹配相位射频脉冲，脑血流测量的时间标准偏差从48mL/100g/min降低到32mL/100g/min，降低了33%，从而改善了脑血流图像质量。这项研究报告说，在不影响信噪比和信号稳定性的情况下，使用匹配相位的RF脉冲可以实现近邻接的多层成像。
The minimum slice spacing in multislice imaging is limited by inter-slice crosstalk due to an imperfect slice profile. This study sought to minimize the slice spacing using matched-phase RF pulses and demonstrate its application in cerebral blood flow imaging using velocity-selective arterial spin labeling. A spin-echo matched-phase 90°–180° RF pair was designed using Shinnar-Le Roux algorithm in order to improve the slice profile of longitudinal magnetization, which plays a more critical role in creating interslice crosstalk than transverse magnetization. Both transverse and longitudinal slice profiles were compared between matched-phase RF and sinc-based RF pulses in simulations and measurements. Velocity-selective arterial spin labeling was performed in normal volunteers using both RF pulses and standard deviation of cerebral blood flow time series was calculated to examine ASL signal stability. Using designed matched-phase RF, the longitudinal slice profile was sharpened without signal-to-noise ratio loss. In velocity-selective arterial spin labeling imaging, the temporal standard deviation of cerebral blood flow measurements was reduced from 48 mL/100 g/min to 32 mL/100 g/min by 33% using matched-phase RF pulses, and as a result, cerebral blood flow image quality improved. This study reports that near-contiguous multislice imaging can be achieved using matched-phase RF pulses without compromising signal-to-noise ratio and signal stability.
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影响因子：
5
作者：
SECHTEM, U;PFLUGFELDER, PW;HIGGINS, CB
通讯作者：
HIGGINS, CB
影响因子：
2.5
作者：
MITCHELL, DG;VINITSKI, S;RIFKIN, MD
通讯作者：
RIFKIN, MD
影响因子：
19.7
作者：
KNEELAND, JB;SHIMAKAWA, A;WEHRLI, FW
通讯作者：
WEHRLI, FW
影响因子：
1.6
作者：
MEIBOOM, S;GILL, D
通讯作者：
GILL, D
影响因子：
2.5
作者：
JUST, M;HIGER, HP;PFANNENSTIEL, P
通讯作者：
PFANNENSTIEL, P