Single-shot T1 mapping using simultaneous acquisitions of spin- and stimulated-echo-planar imaging (2D ss-SESTEPI).
Single-shot T1 mapping using simultaneous acquisitions of spin- and stimulated-echo-planar imaging (2D ss-SESTEPI).
复制标题
使用同时采集自旋和受激回波平面成像 (2D ss-SESTEPI) 的单次 T1 映射。
DOI：
10.1002/mrm.22367
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发表时间：
2010
影响因子：
3.3
通讯作者：
Jeong,Eun-Kee
中科院分区：
文献类型：
--
作者：
Shi,Xianfeng;Kim,Seong-Eun;Jeong,Eun-Kee
传统的受激回波NMR序列仅测量纵向分量，而在翻转准备好的磁化后丢弃横向分量。除了受激回波之外，该横向磁化还可以用于测量自旋回波。二维单次激发自旋和受激回波平面成像（ss‐SESTEPI）是一种基于回波平面成像的单次激发成像技术，可在单次射频激发后同时采集自旋回波平面图像和受激回波平面图像。自旋回波平面图像和受激回波平面图像的幅度因T1衰减和弥散加权而不同，适用于完美90°射频，因此可用于快速测量T1。然而，射频场幅度的空间变化会导致成像视场内自旋回波平面图像和受激回波平面图像的横向磁化不均匀分裂。因此，对射频场不均匀性幅度的校正对于用于T1测量的二维ss-SESTEPI至关重要。我们开发了一种用于射频场不均匀性振幅校正的方法，通过以最小混合时间采集额外的受激回波平面图像，计算自旋回波和受激回波之间的差异，并将受激回波平面图像乘以逆功能图。通过测量预扫描期间的平均扩散率来校正扩散诱导衰减。快速单次激发T1标测可用于各种应用，例如动态T1标测，用于动态对比增强MRI中造影剂浓度的真实的实时估计。Magn Reson Med，2010年。© 2010 Wiley利斯公司
The conventional stimulated‐echo NMR sequence only measures the longitudinal component while discarding the transverse component, after tipping up the prepared magnetization. This transverse magnetization can be used to measure a spin echo, in addition to the stimulated echo. Two‐dimensional single‐shot spin‐ and stimulated‐echo‐planar imaging (ss‐SESTEPI) is an echo‐planar‐imaging‐based single‐shot imaging technique that simultaneously acquires a spin‐echo‐planar image and a stimulated‐echo‐planar image after a single radiofrequency excitation. The magnitudes of the spin‐echo‐planar image and stimulated‐echo‐planar image differ byT1decay and diffusion weighting for perfect 90° radiofrequency and thus can be used to rapidly measureT1. However, the spatial variation of amplitude of radiofrequency field induces uneven splitting of the transverse magnetization for the spin‐echo‐planar image and stimulated‐echo‐planar image within the imaging field of view. Correction for amplitude of radiofrequency field inhomogeneity is therefore critical for two‐dimensional ss‐SESTEPI to be used forT1measurement. We developed a method for amplitude of radiofrequency field inhomogeneity correction by acquiring an additional stimulated‐echo‐planar image with minimal mixing time, calculating the difference between the spin echo and the stimulated echo and multiplying the stimulated‐echo‐planar image by the inverse functional map. Diffusion‐induced decay is corrected by measuring the average diffusivity during the prescanning. Rapid single‐shotT1mapping may be useful for various applications, such as dynamicT1mapping for real‐time estimation of the concentration of contrast agent in dynamic contrast enhancement MRI. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.