Quantitative mapping of developing fetal organs using dynamic MRI and artificial neural networksare Technologies

胎儿的定量T1和T2映射有可能允许表征组织特性的细微变化。正常的发育过程，如髓鞘形成，变化的微观结构和水含量是众所周知的T1和T2弛豫时间，反映了组织的基本生物学特性有深远的影响。识别由病理、炎症或损伤引起的这些值的细微变化需要完全定量的测量。然而，胎动对已建立的定量方法提出了严峻的挑战。许多最先进的神经成像qMRI方法需要多次冗长的3D采集和稳态序列2，这些序列很容易被运动破坏，因此与胎儿成像不兼容。最近的进展已经通过使用“切片到体积配准”（SVR）方法产生了运动胎儿的高质量3D非定量解剖图像，该方法使用图像配准3从多个2D图像中组装3D图像（参见图1和图2）。该项目的目的是开发创新的抗运动切片选择序列，该序列可以重建成高分辨率一致的定量图。人工智能方法（深度神经网络）将被用来提供一个易于处理的解决方案，通过模拟与胎儿运动的相互作用，从非稳态序列中估计弛豫时间的复杂逆问题。新开发的抗运动定量技术将被应用于胎儿大脑和其他器官，以评估其诊断价值，并便于将胎儿大脑发育与产前进行比较。足月新生儿

Quantitative T1 and T2 mapping of the fetus has potential to allow characterisation of subtle changes in tissue properties. Normal developmental processes such as myelination, changing microstructure and water content are known to have profound effect on T1 and T2 relaxation times1, which reflect fundamental biological properties of the tissues. Identifying subtle changes to these values resulting from pathology, inflammation or injury would require fully quantitative measurements.However, the fetal motion presents a serious challenge to established quantitative methods. Many state-of-the-art neuroimaging qMRI methods require multiple lengthy 3D acquisitions and steady-state sequences2 that are easily disrupted by motion, and are thus incompatible with fetal imaging. Recent advancements have produced high quality 3D non-quantitative anatomical images of moving fetuses by using a "slice to volume registration" (SVR) approach, which assembles a 3D image from multiple 2D images using image registration3 (see Fig. 1 and 2).The aim of the project is to develop innovative motion resistant slice-selective sequences that can be reconstructed into high resolution consistent quantitative maps. Artificial intelligence methods (deep neural networks) will be employed to provide a tractable solution to a complex inverse problem of estimation of relaxation times from the non-steady state sequences by modelling interaction with fetal motion.The newly developed motion resistant quantitative techniques will be applied to fetal brain and other organs to assess their diagnostic value and facilitate comparison of fetal brain development with pre-term neonatal population.