Impact of reduced k-space acquisition on pathologic detectability for volumetric MR spectroscopic imaging.
Impact of reduced k-space acquisition on pathologic detectability for volumetric MR spectroscopic imaging.
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DOI：
10.1002/jmri.24130
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发表时间：
2014-01
影响因子：
4.4
通讯作者：
Maudsley, Andrew A.
中科院分区：
文献类型：
--
作者：
Sabati, Mohammad;Zhan, Jiping;Govind, Varan;Arheart, Kristopher L.;Maudsley, Andrew A.
关键词：
评估加速采集对容积MR波谱成像（MRSI）频谱质量的影响，并评价其检测轻度损伤代谢变化的能力。首先描述了用于高分辨率全脑回波平面SI（EPSI）序列的广义自动校准部分并行采集（GRAPPA）方法的实现，并使用正常受试者和轻度创伤性脑损伤（mTBI）患者的基于叶和体素的分析研究了GRAPPA-EPSI方法的频谱准确性。将GRAPPA的性能与完全编码的EPSI的性能进行了比较，用于在同一扫描会话中从正常受试者收集的5个数据集，以及模拟减少k空间采样的45次扫描（20名正常受试者和25名mTBI患者）。为了比较，还模拟了中心k空间较低分辨率3D-EPSI采集。使用分为半球脑叶和组织类型的分析，对mTBI组相对于年龄匹配的对照受试者的个体代谢物和代谢物比率分布的差异进行统计学评估。16分钟扫描时间的GRAPPA-EPSI在MRSI定量、光谱拟合和准确度方面与完全采样的3D-EPSI采集产生了稳健且相似的结果，并且比中心k空间采集更准确。主要发现包括GRAPPA和完全采样结果之间的高度相关性（准确度为92.6%）。尽管简化编码方法与影响频谱分析质量的较低SNR相关，但当使用灵敏度受限的体积MRSI时，使用并行成像方法可以导致与完全采样数据相同的诊断结果。
To assess the impact of accelerated acquisitions on the spectral quality of volumetric MR spectroscopic imaging (MRSI) and to evaluate their ability in detecting metabolic changes with mild injury. The implementation of a generalized autocalibrating partially parallel acquisition (GRAPPA) method for a high-resolution whole-brain echo planar SI (EPSI) sequence is first described and the spectral accuracy of the GRAPPA-EPSI method is investigated using lobar and voxel-based analyses for normal subjects and patients with mild traumatic brain injuries (mTBI). The performance of GRAPPA was compared with that of fully-encoded EPSI for 5 datasets collected from normal subjects at the same scanning session, as well as on 45 scans (20 normal subjects and 25 mTBI patients) for which the reduced k-space sampling was simulated. For comparison, a central k-space lower-resolution 3D-EPSI acquisition was also simulated. Differences in individual metabolites and metabolite ratio distributions of the mTBI group relative to those of age-matched control subjects were statistically evaluated using analyses divided into hemispheric brain lobes and tissue types. GRAPPA-EPSI with 16-min scan time yielded robust and similar results in terms of MRSI quantitation, spectral fitting, and accuracy with that of fully sampled 3D-EPSI acquisitions and was more accurate than central k-space acquisition. Primary findings included high correlations (accuracy of 92.6%) between the GRAPPA and fully sampled results. Although the reduced encoding method is associated with lower SNR that impact the quality of spectral analysis the use of parallel imaging method can lead to same diagnostic outcomes as of the fully sampled data when using the sensitivity-limited volumetric MRSI.
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影响因子：
3.3
作者：
ADALSTEINSSON, E;IRARRAZABAL, P;MACOVSKI, A
通讯作者：
MACOVSKI, A
影响因子：
3.3
作者：
Adalsteinsson, E;Irarrazabal, P;Spielman, DM
通讯作者：
Spielman, DM
影响因子：
3.3
作者：
Sodickson, DK;Manning, WJ
通讯作者：
Manning, WJ
影响因子：
3.3
作者：
Mayer, Dirk;Kim, Dong-Hyun;Bammer, Roland
通讯作者：
Bammer, Roland
影响因子：
3.3
作者：
Dydak, U;Pruessmann, KP;Boesiger, P
通讯作者：
Boesiger, P