Efficient imaging of midbrain nuclei using inverse double-echo steady-state acquisition.
Efficient imaging of midbrain nuclei using inverse double-echo steady-state acquisition.
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DOI：
10.1118/1.4922402
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发表时间：
2015-07
期刊：
影响因子：
3.8
通讯作者：
Ming-Long Wu;Hing-Chiu Chang;Tzu‐cheng Chao;N. Chen
中科院分区：
文献类型：
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作者：
Ming-Long Wu;Hing-Chiu Chang;Tzu‐cheng Chao;N. Chen
使用T2或T2* 加权MRI进行中脑核团成像通常需要较长的回波时间，导致扫描时间较长。在这项研究中，一个反向双回波稳态（iDESS）技术提出了有效地描绘中脑核团。方法13名健康受试者参加本研究。沿着进行iDESS，并使用两组T2* 加权扰相梯度回波图像（SPGR 1，扫描时间与iDESS和SPGR 2相同，使用临床扫描参数作为参考标准）进行比较。结合两个回波信号的iDESS复合图像的生成针对红核与周围组织之间的最大对比噪声比（CNR）进行了优化。根据枕叶计算信噪比（SNR）。还使用标准磁敏感加权成像（SWI）中的相位增强图像进行了比较。结果iDESS图像的SNR效率（171.3）显著高于SPGR 1（158.7，p = 0.013）和SPGR 2（95.5，p < 10（-8））。iDESS CNR效率（19.2）也显著高于SPGR 1（6.9，p < 10（-6））和SPGR 2（14.3，p = 0.0016）。与DESS相比，iDESS在增强相位信息方面提供了进一步的优势，从而提高了SWI处理图像的对比度。结论：iDESS有效地描绘了中脑核团，提高了CNR效率，增加了SNR效率，减少了扫描时间，并且不易于从空气-组织界面丢失敏感性信号。
PURPOSE Imaging of midbrain nuclei using T2- or T2*-weighted MRI often entails long echo time, leading to long scan time. In this study, an inverse double-echo steady-state (iDESS) technique is proposed for efficiently depicting midbrain nuclei. METHODS Thirteen healthy subjects participated in this study. iDESS was performed along with two sets of T2*-weighted spoiled gradient-echo images (SPGR1, with scan time identical to iDESS and SPGR2, using clinical scanning parameters as a reference standard) for comparison. Generation of iDESS composite images combining two echo signals was optimized for maximal contrast-to-noise ratio (CNR) between the red nuclei and surrounding tissues. Signal-to-noise ratios (SNRs) were calculated from the occipital lobe. Comparison was also made using phase-enhanced images as in standard susceptibility-weighted imaging (SWI). RESULTS The iDESS images present significantly higher SNR efficiency (171.3) than SPGR1 (158.7, p = 0.013) and SPGR2 (95.5, p < 10(-8)). iDESS CNR efficiency (19.2) is also significantly greater than SPGR1 (6.9, p < 10(-6)) and SPGR2 (14.3, p = 0.0016). Compared with DESS, iDESS provides further advantage on enhanced phase information and hence improved contrast on SWI-processed images. CONCLUSIONS iDESS efficiently depicts midbrain nuclei with improved CNR efficiency, increased SNR efficiency, and reduced scan time and is less prone to susceptibility signal loss from air-tissue interfaces.