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arXiv 2312.11468physics.med-phcs.CV
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用于定量MRI参数估计的偏差减少神经网络

Bias-Reduced Neural Networks for Parameter Estimation in Quantitative MRI

New York University Grossman School of Medicine(纽约大学格罗斯曼医学院);Bernard and Irene Schwartz Center for Biomedical Imaging(伯纳德和艾琳·施瓦茨生物医学成像中心);Vilcek Institute of Graduate Biomedical Sciences(维尔cek研究生生物医学科学研究院)

Andrew Mao, Sebastian Flassbeck, Jakob Assländer

AI总结:

本文提出一种偏差减少的神经网络定量MRI参数估计方法,通过推广均方误差损失控制偏差与方差,在仿真和体内实验中均验证了其接近Cramér-Rao界的方差和优于现有NN与传统方法的精度与效率。

摘要:

目的:开发基于神经网络(NN)的定量MRI参数估计器,使其偏差最小且方差接近Cramér-Rao界。理论与方法:我们推广均方误差损失以控制NN估计的偏差和方差,这涉及在训练期间对同一测量的多个噪声实现进行平均。针对两个神经影像应用研究了所得NN的偏差和方差特性。结果:在仿真中,所提出的策略在整个参数空间内降低了估计的偏差,并实现了接近Cramér-Rao界的方差。在体内实验中,我们观察到使用所提出的NN估计的参数图与传统估计器(如非线性最小二乘拟合)之间具有良好的一致性,而最先进的NN则显示出更大的偏差。结论:与使用均方误差训练的NN相比,所提出的NN大大减少了偏差,并且与传统估计器相比,在具有可比或更好精度的同时,显著提高了计算效率。

英文摘要:

Purpose: To develop neural network (NN)-based quantitative MRI parameter estimators with minimal bias and a variance close to the Cramér-Rao bound. Theory and Methods: We generalize the mean squared error loss to control the bias and variance of the NN's estimates, which involves averaging over multiple noise realizations of the same measurements during training. Bias and variance properties of the resulting NNs are studied for two neuroimaging applications. Results: In simulations, the proposed strategy reduces the estimates' bias throughout parameter space and achieves a variance close to the Cramér-Rao bound. In vivo, we observe good concordance between parameter maps estimated with the proposed NNs and traditional estimators, such as non-linear least-squares fitting, while state-of-the-art NNs show larger deviations. Conclusion: The proposed NNs have greatly reduced bias compared to those trained using the mean squared error and offer significantly improved computational efficiency over traditional estimators with comparable or better accuracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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