Improving whole brain structural MRI at 4.7 Tesla using 4 irregularly shaped receiver coils
Improving whole brain structural MRI at 4.7 Tesla using 4 irregularly shaped receiver coils
复制标题
DOI：
10.1016/j.neuroimage.2006.04.191
复制
发表时间：
2006-09-01
期刊：
影响因子：
5.7
通讯作者：
Ordidge, Roger J.
中科院分区：
文献类型：
--
作者：
Carmichael, David W.;Thomas, David L.;Ordidge, Roger J.
更高的磁场强度（>= 3 T）和多个接收器阵列线圈都可以为MRI提供增加的信噪比（SNR）。SNR的增加可用于获得更高分辨率的图像，从而更好地可视化人脑内的结构。然而，高场强系统还遭受增加的Ill非均匀性和增加的功率沉积，更快地达到比吸收率（SAR）极限。为了缓解这些问题，仔细选择的脉冲序列设计和发射RF线圈是required.This本文介绍了使用一个原型阵列线圈组成的4个不规则形状的线圈在一个标准配置的神经成像在4.7 T（头部发射/接收体积线圈，以尽量减少SAR和头部梯度插入最大的梯度性能）。通过针对4.7 T优化的快速自旋回波（FSE）脉冲序列，可以在大脑容量范围内显着提高质量和分辨率。使用阵列线圈，相对于体积线圈，在中枢脑区域中获得1 - 1.5倍的SNR改善，在皮质区域中获得2-3倍的SNR改善。分辨率为352 x 352 x 2000 Pro的阵列线圈图像在中心区域的SNR为16.0至26.2，在皮质区域的SNR为19.9至34.8。这样的图像很容易显示皮质脊髓结构，同时在类似于12分钟的扫描中仍然覆盖大部分大脑。(c)2006年爱思唯尔公司All rights reserved.
Both higher magnetic field strengths (>= 3 T) and multiple receiver,array coils' can provide increased signal-to-noise ratio (SNR) for MRI. This increase in SNR can be used to obtain images with higher resolution, enabling better visualisation of structures within the human brain. However, high field strength systems also suffer from increased Ill non-uniformity and increased power deposition, reaching specific absorption rate (SAR) limits more quickly. For these problems to be mitigated, a careful choice of both the pulse sequence design and transmit RF coil is required.This paper describes the use of a prototype array coil consisting of 4 irregularly shaped coils within a standard configuration for neuroimaging at 4.7 T (a head transmit/receive volume coil to minimise SAR and a head gradient insert for maximum gradient performance). With a fast spin echo (FSE) pulse sequence optimised for 4.7 T, this provides dramatically increased quality and resolution over a large brain volume. Using the array coil, a SNR improvement relative to the volume coil of 1 - 1.5 times in central brain areas and 2-3 times in cortical regions was obtained. Array coil images with a resolution of 352 x 352 x 2000 Pro had a SNR of 16.0 to 26.2 in central regions and 19.9 to 34.8 in cortical areas. Such images easily demonstrate cortical myeloarchitecture, while still covering most of the brain in a similar to 12 min scan. (c) 2006 Elsevier Inc. All rights reserved.