Comparison of image sensitivity between conventionaltensor-based and fast diffusion kurtosis imaging protocols in a rodent model ofacute ischemic stroke
Comparison of image sensitivity between conventionaltensor-based and fast diffusion kurtosis imaging protocols in a rodent model ofacute ischemic stroke
复制标题
急性缺血性中风啮齿动物模型中传统张量成像方案和快速扩散峰度成像方案的图像灵敏度比较
DOI：
10.1002/nbm.3506
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发表时间：
2016
影响因子：
2.9
通讯作者：
Phillip Zhe Sun
中科院分区：
文献类型：
--
作者：
Yin Wu;Jinsuh Kim;Suk-Tak Chan;Iris Yuwen Zhou;Yingkun Guo;Takahiro Igarashi;Hairong Zheng;Gang Guo;Phillip Zhe Sun
弥散峰度成像(DKI)为改善急性缺血性卒中不同组织损伤的分层提供了一种有用的补充工具，可作为常规扩散磁共振成像的补充。然而，其相对较长的成像时间阻碍了其在急诊环境中的临床应用。最近提出的一种快速DKI方法大大缩短了成像时间，这可能有助于克服扫描时间限制。然而，到目前为止，快速DKI方案对急性卒中成像的敏感性还没有得到充分的描述。在这项研究中，我们在一个急性卒中的啮齿动物模型上进行了常规和快速的DKI扫描，并比较了弥散率和峰度指数(即轴向、径向和平均值)在描述急性缺血性病变方面的敏感性。此外，我们使用常规和快速DKI方法分析了同侧缺血区和对侧正常区之间的对比噪声比(CNR)。结果发现，平均峰度在缺血区和对侧正常区之间的相对变化量为47.1 ± 7.3%，是反映急性缺血性损伤最敏感的参数。这两种DKI方法产生的扩散率和峰度测量与病变体积高度相关(R2⩾ 0.90p<；(0.01))。重要的是，快速DKI方法的平均峰度CNR(1.6 ± 0.2)显著高于常规张量法(1.3 ± 0.2，p<；0.05)，当考虑扫描时间时，其单位时间CNR效率(CNR效率)几乎翻了一番。总之，快速DKI方法对急性缺血性组织损伤的成像具有极高的敏感性和效率，这对于影像引导和个体化治疗中风是必不可少的。版权所有©2016 John Wiley&Sons，Ltd.
Diffusion kurtosis imaging (DKI) can offer a useful complementary tool to routine diffusion MRI for improved stratification of heterogeneous tissue damage in acute ischemic stroke. However, its relatively long imaging time has hampered its clinical application in the emergency setting. A recently proposed fast DKI approach substantially shortens the imaging time, which may help to overcome the scan time limitation. However, to date, the sensitivity of the fast DKI protocol for the imaging of acute stroke has not been fully described. In this study, we performed routine and fast DKI scans in a rodent model of acute stroke, and compared the sensitivity of diffusivity and kurtosis indices (i.e. axial, radial and mean) in depicting acute ischemic lesions. In addition, we analyzed the contrast‐to‐noise ratio (CNR) between the ipsilateral ischemic and contralateral normal regions using both conventional and fast DKI methods. We found that the mean kurtosis shows a relative change of 47.1 ± 7.3% between the ischemic and contralateral normal regions, being the most sensitive parameter in revealing acute ischemic injury. The two DKI methods yielded highly correlated diffusivity and kurtosis measures and lesion volumes (R2⩾ 0.90,p< 0.01). Importantly, the fast DKI method exhibited significantly higher CNR of mean kurtosis (1.6 ± 0.2) compared with the routine tensor protocol (1.3 ± 0.2,p< 0.05), with its CNR per unit time (CNR efficiency) approximately doubled when the scan time was taken into account. In conclusion, the fast DKI method provides excellent sensitivity and efficiency to image acute ischemic tissue damage, which is essential for image‐guided and individualized stroke treatment. Copyright © 2016 John Wiley & Sons, Ltd.