PDF(Pubmed)
Abstract：
Diffusion magnetic resonance imaging (dMRI) is pivotal for probing the microstructure of the rapidly-developing fetal brain. However, fetal motion during scans and its interaction with magnetic field inhomogeneities result in artifacts and data scattering across spatial and angular domains. The effects of those artifacts are more pronounced in high-angular resolution fetal dMRI, where signal-to-noise ratio is very low. Those effects lead to biased estimates and compromise the consistency and reliability of dMRI analysis. This work presents HAITCH, the first and the only publicly available tool to correct and reconstruct multi-shell high-angular resolution fetal dMRI data. HAITCH offers several technical advances that include a blip-reversed dual-echo acquisition for dynamic distortion correction, advanced motion correction for model-free and robust reconstruction, optimized multi-shell design for enhanced information capture and increased tolerance to motion, and outlier detection for improved reconstruction fidelity. The framework is open-source, flexible, and can be used to process any type of fetal dMRI data including single-echo or single-shell acquisitions, but is most effective when used with multi-shell multi-echo fetal dMRI data that cannot be processed with any of the existing tools. Validation experiments on real fetal dMRI scans demonstrate significant improvements and accurate correction across diverse fetal ages and motion levels. HAITCH successfully removes artifacts and reconstructs high-fidelity fetal dMRI data suitable for advanced diffusion modeling, including fiber orientation distribution function estimation. These advancements pave the way for more reliable analysis of the fetal brain microstructure and tractography under challenging imaging conditions.
摘要：
扩散磁共振成像（dMRI）对于探测快速发育的胎儿大脑的微观结构至关重要。然而,扫描过程中的胎儿运动及其与磁场不均匀性的相互作用会导致伪影和数据在空间和角域上的散射。这些伪影的影响在高角度分辨率胎儿dMRI中更为明显，其中信噪比非常低。这些影响导致有偏差的估计，并损害了dMRI分析的一致性和可靠性。这项工作介绍了HAITCH，第一个也是唯一一个公开的工具来纠正和重建多壳高分辨率胎儿dMRI数据。HAITCH提供了一些技术进步，包括动态失真校正的反向双回波采集，用于无模型和鲁棒重建的高级运动校正，优化的多壳设计，以增强信息捕获和增加运动公差，和异常值检测，以提高重建保真度。该框架是开源的，灵活,可用于处理任何类型的胎儿dMRI数据，包括单回波或单壳采集，但当与无法用任何现有工具处理的多壳多回波胎儿dMRI数据一起使用时最有效。对真实胎儿dMRI扫描的验证实验表明，在不同的胎儿年龄和运动水平上有显着的改善和准确的校正。HAITCH成功去除伪影并重建了适用于高级扩散建模的高保真胎儿dMRI数据，包括纤维取向分布函数估计。这些进步为在具有挑战性的成像条件下更可靠地分析胎儿脑微结构和纤维束造影铺平了道路。
