Steer-PROP: a GRASE-PROPELLER sequence with interecho steering gradient pulses.
Steer-PROP: a GRASE-PROPELLER sequence with interecho steering gradient pulses.
复制标题
Steer-PROP：带有回波间转向梯度脉冲的 GRASE-PROPELLER 序列。
DOI：
10.1002/mrm.26898
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发表时间：
2018
影响因子：
3.3
通讯作者：
Zhou,XiaohongJoe
中科院分区：
文献类型：
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作者：
Srinivasan,Girish;Rangwala,Novena;Zhou,XiaohongJoe
目的本研究证明了一种新的PROPELLER（周期性旋转重叠平行线增强重建）脉冲序列，称为Steer-PROP，基于梯度和自旋回波（GRASE），以减少成像时间并解决GRASE固有的相位误差。该研究还说明了使用Steer-PROP作为单次激发回波平面成像（SS-EPI）的替代方案的可行性，以在所有成像planes. MethodsSteer-PROP中产生无失真的扩散图像使用一系列的blip梯度脉冲在每个重复时间内产生N（N= 3 - 5）个相邻的k-空间叶片，其中N是梯度回波在GRASE序列的数量。这种采样策略使相位校正算法能够系统地解决GRASE相位误差以及运动引起的相位不一致性。Steer-PROP在1.5T和3.0T的T2和弥散加权成像条件下在体模和健康人受试者上进行了评估。ResultsSteer-PROP产生的图像质量与基于快速自旋回波（FSE）的传统PROPELLER相似，但仅采集一部分（例如，1/3）的扫描时间。Steer-PROP的运动鲁棒性与基于FSE的PROPELLER相当。使用Steer-PROP，在所有成像平面上从人类受试者获得高质量和无失真的扩散图像，显示出比SS-EPI.ConclusionThe建议的Steer-PROP序列相比，FSE-基于PROPELLER可以大大减少扫描时间，同时达到足够的图像质量。Steer-PROP中的新型k空间采样策略不仅可以实现集成相位校正方法，解决各种相位误差来源，而且与其他采样策略相比，还可以最大限度地减少回波间隔。Steer‐PROP也可以作为SS‐EPI的可行替代方案，以减少所有成像平面的图像失真。Magn Reson Med 79：2533-2541，2018。© 2017国际医学磁共振学会。
PurposeThis study demonstrates a novel PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) pulse sequence, termed Steer‐PROP, based on gradient and spin echo (GRASE), to reduce the imaging times and address phase errors inherent to GRASE. The study also illustrates the feasibility of using Steer‐PROP as an alternative to single‐shot echo planar imaging (SS‐EPI) to produce distortion‐free diffusion images in all imaging planes.MethodsSteer‐PROP uses a series of blip gradient pulses to produceN(N= 3‐5) adjacentk‐space blades in each repetition time, whereNis the number of gradient echoes in a GRASE sequence. This sampling strategy enables a phase correction algorithm to systematically address the GRASE phase errors as well as the motion‐induced phase inconsistency. Steer‐PROP was evaluated on phantoms and healthy human subjects at both 1.5T and 3.0T forT2‐ and diffusion‐weighted imaging.ResultsSteer‐PROP produced similar image quality as conventional PROPELLER based on fast spin echo (FSE), while taking only a fraction (e.g., 1/3) of the scan time. The robustness against motion in Steer‐PROP was comparable to that of FSE‐based PROPELLER. Using Steer‐PROP, high quality and distortion‐free diffusion images were obtained from human subjects in all imaging planes, demonstrating a considerable advantage over SS‐EPI.ConclusionThe proposed Steer‐PROP sequence can substantially reduce the scan times compared with FSE‐based PROPELLER while achieving adequate image quality. The novelk‐space sampling strategy in Steer‐PROP not only enables an integrated phase correction method that addresses various sources of phase errors, but also minimizes the echo spacing compared with alternative sampling strategies. Steer‐PROP can also be a viable alternative to SS‐EPI to decrease image distortion in all imaging planes. Magn Reson Med 79:2533–2541, 2018. © 2017 International Society for Magnetic Resonance in Medicine.