Temporal Signal-to-Noise Changes in Combined Multislice- and In-Plane-Accelerated Echo-Planar Imaging with a 20- and 64-Channel Coil
Temporal Signal-to-Noise Changes in Combined Multislice- and In-Plane-Accelerated Echo-Planar Imaging with a 20- and 64-Channel Coil
复制标题
使用 20 和 64 通道线圈组合多层和面内加速回波平面成像中的时间信噪比变化
作者：
Philipp Seidel;S. Levine;Marlene Tahedl;J. Schwarzbach
平面回波成像(EPI)是功能磁共振成像中最常见的获取血氧水平依赖(BOLD)对比度的方法，可以在几秒钟内获得整个大脑体积。然而，由于成像协议受到硬件的限制(例如，快速梯度切换)，研究人员必须在空间分辨率、时间分辨率或全脑覆盖范围之间进行折衷。早期绕过这个问题的尝试包括开发更快地(即，面内加速(S))或同时(即，多切片加速(M))获取体积切片的方案。然而，应用加速方法可能会导致时间信噪比(TSNR)的降低，tSNR是衡量信号随时间变化的稳定性的关键指标。使用20通道和通道的接收器线圈，我们发现，无论接收器线圈是什么，启用S加速都会导致tSNR显著降低，而M加速产生的tSNR下降不那么明显。此外，tSNR的损失倾向于发生在大脑的颞区、岛区和内侧区，使用20通道线圈时更加明显，而使用通道线圈时，额顶外侧区域的tSNR保持相对稳定，最高可达M加速度的6倍，产生与无加速度相当的tSNR。这样的方法学探索可以指导研究人员和临床医生根据研究中的大脑区域优化成像方案。
Echo-planar imaging (EPI) is the most common method of functional MRI for acquiring the blood oxygenation level-dependent (BOLD) contrast, allowing the acquisition of an entire brain volume within seconds. However, because imaging protocols are limited by hardware (e.g., fast gradient switching), researchers must compromise between spatial resolution, temporal resolution, or whole-brain coverage. Earlier attempts to circumvent this problem included developing protocols in which slices of a volume were acquired faster (i.e., in-plane acceleration (S)) or simultaneously (i.e., multislice acceleration (M)). However, applying acceleration methods can lead to a reduction in the temporal signal-to-noise ratio (tSNR): a critical measure of signal stability over time. Using a 20- and 64-channel receiver coil, we show that enabling S-acceleration consistently yielded a substantial decrease in tSNR, regardless of the receiver coil, whereas M-acceleration yielded less pronounced tSNR decrease. Moreover, tSNR losses tended to occur in temporal, insular, and medial brain regions and were more noticeable with the 20-channel coil, while with the 64-channel coil, the tSNR in lateral frontoparietal regions remained relatively stable up to six-fold M-acceleration producing comparable tSNR to that of no acceleration. Such methodological explorations can guide researchers and clinicians in optimizing imaging protocols depending on the brain regions under investigation.
影响因子：
56.9
作者：
BELLIVEAU, JW;KENNEDY, DN;ROSEN, BR
通讯作者：
ROSEN, BR
DOI：
10.1073/pnas.89.12.5675
发表时间：
1992-06-15
影响因子：
11.1
作者：
KWONG, KK;BELLIVEAU, JW;ROSEN, BR
通讯作者：
ROSEN, BR