Evaluation of non-Gaussian diffusion in cardiac MRI.
Evaluation of non-Gaussian diffusion in cardiac MRI.
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DOI：
10.1002/mrm.26466
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发表时间：
2017-09
影响因子：
3.3
通讯作者：
Schneider JE
中科院分区：
文献类型：
--
作者：
McClymont D;Teh I;Carruth E;Omens J;McCulloch A;Whittington HJ;Kohl P;Grau V;Schneider JE
扩散张量模型假设为高斯扩散，在心脏扩散磁共振成像中得到了广泛的应用。然而，由于细胞和组织微结构的阻碍和限制，生物组织中的扩散偏离了高斯分布，可以用非高斯模型更好地量化。这项研究的目的是调查健康和肥厚心脏中的非高斯扩散。对13只大鼠心脏(5只健康、4只假心脏、4只肥大)进行了体外成像。在b值高达10,000 S/mm~2时获得弥散加权图像。扩散模型与数据相吻合，并根据Akaike信息标准进行排序。扩散张量在b值为2000 S/mm~2时最好，但在高b值区域反映信号较差，其中最好的模型是非高斯“贝塔分布”模型。尽管健康心脏、假心脏和肥厚心脏的表观弥散系数有相当大的重叠，但肥厚心脏的弥散峰度和偏斜度在小片和小片-正常方向上高出20%以上。与高斯扩散模型相比，非高斯扩散模型对肥大的检测具有更高的灵敏度。特别是，弥散峰度可以作为一种有用的生物标志物来表征心脏疾病和重塑。Magn Reson Med 78：1174-1186,2017。©2016国际核磁共振医学学会。
The diffusion tensor model assumes Gaussian diffusion and is widely applied in cardiac diffusion MRI. However, diffusion in biological tissue deviates from a Gaussian profile as a result of hindrance and restriction from cell and tissue microstructure, and may be quantified better by non‐Gaussian modeling. The aim of this study was to investigate non‐Gaussian diffusion in healthy and hypertrophic hearts. Thirteen rat hearts (five healthy, four sham, four hypertrophic) were imaged ex vivo. Diffusion‐weighted images were acquired at b‐values up to 10,000 s/mm2. Models of diffusion were fit to the data and ranked based on the Akaike information criterion. The diffusion tensor was ranked best at b‐values up to 2000 s/mm2 but reflected the signal poorly in the high b‐value regime, in which the best model was a non‐Gaussian “beta distribution” model. Although there was considerable overlap in apparent diffusivities between the healthy, sham, and hypertrophic hearts, diffusion kurtosis and skewness in the hypertrophic hearts were more than 20% higher in the sheetlet and sheetlet‐normal directions. Non‐Gaussian diffusion models have a higher sensitivity for the detection of hypertrophy compared with the Gaussian model. In particular, diffusion kurtosis may serve as a useful biomarker for characterization of disease and remodeling in the heart. Magn Reson Med 78:1174–1186, 2017. © 2016 International Society for Magnetic Resonance in Medicine.