Li Hua, Nikam Rahul, Kandula Vinay, Chow Ho Ming, Choudhary Arabinda K
Katzin Diagnostic & Research PET/MR Center, Nemours - Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA.
Department of Radiology, Nemours - Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA.
Magn Reson Imaging. 2019 Apr;57:151-155. doi: 10.1016/j.mri.2018.11.021. Epub 2018 Nov 26.
Neurite orientation dispersion and density imaging (NODDI) is a clinically feasible approach to measure intra-neurite volume fraction (f). However, the sophisticated fitting procedure takes several hours. And the NODDI model relied on several questionable assumptions. Recent analytical work demonstrated that f could be simply calculated from the spherical mean signal (MEANS) averaged over all gradient directions with a more solid theoretical foundation. The current study aims to compare NODDI and MEANS for measuring f in human brain and investigate the potential of MEANS as a fast approach in clinics.
NODDI f and MEANS f were measured and compared on the same dataset. NODDI f was obtained using the NODDI MATLAB Toolbox. MEANS f is the product of the spherical mean signal and 2bD/π, where D is the intra-neurite intrinsic diffusivity.
NODDI f and MEANS f maps are similar. The voxel-by-voxel correlation suggests that NODDI f and MEANS f are approximately equivalent to each other.
MEANS may have potential to serve a fast and simple approach to estimate f in clinics.
神经突方向离散度与密度成像（NODDI）是一种临床上可行的测量神经突内体积分数（f）的方法。然而，其复杂的拟合过程需要数小时。并且NODDI模型依赖于几个值得怀疑的假设。最近的分析工作表明，f可以通过对所有梯度方向上的球平均信号（MEANS）进行简单计算得出，且具有更坚实的理论基础。本研究旨在比较NODDI和MEANS在测量人脑f方面的差异，并探讨MEANS作为临床快速方法的潜力。
在同一数据集上测量并比较NODDI的f和MEANS的f。使用NODDI MATLAB工具箱获得NODDI的f。MEANS的f是球平均信号与2bD/π的乘积，其中D是神经突内固有扩散率。
NODDI的f图和MEANS的f图相似。逐体素相关性表明NODDI的f和MEANS的f彼此大致等效。
MEANS可能有潜力成为临床上快速、简单估计f的方法。
