An automated pipeline for quantitative T2* fetal body MRI and segmentation at low field
An automated pipeline for quantitative T2* fetal body MRI and segmentation at low field
复制标题
用于定量 T2* 胎儿体 MRI 和低场分割的自动化流程
DOI：
10.1007/978-3-031-43990-2_34
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
J. Hutter
中科院分区：
文献类型：
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作者：
K. Payette;Alena Uus;Jordina Aviles Verdera;C. Zampieri;M. Hall;L. Story;Maria Deprez;M. Rutherford;J. Hajnal;S. Ourselin;Raphaël Tomi;J. Hutter
低场强下的胎儿磁共振成像正在成为围产期健康的一个令人兴奋的方向。临床低场（0.55T）扫描仪有利于胎儿成像，因为它们减少了易磁化性引起的伪影，增加了T2* 值，并且孔径更宽（为越来越肥胖的孕妇人群拓宽了通道）。然而，缺乏标准的自动化图像处理工具，如分割和重建阻碍了更广泛的临床应用。在这项研究中，我们介绍了一个半自动流水线，使用定量MRI的胎儿身体在低场强导致快速和详细的定量T2* 弛豫分析的所有主要胎儿身体器官。采集胎儿身体的多回波动态序列，并使用可变形切片到体积重建将其重建为单个高分辨率体积，生成结构和定量T2* 3D体积。创建使用半监督方法训练的神经网络，以将这些胎儿身体3D体积自动分割成10个不同的器官（导致10个器官中有8个的骰子值> 0.74）。T2* 值揭示了肺、肝和肾实质中与GA的强相关性（R^2>0.5）。该管道成功用于广泛的GA（17-40周），并且对运动伪影具有鲁棒性。低场胎儿MRI可用于执行高级MRI分析，并且是临床扫描的可行选择。
Fetal Magnetic Resonance Imaging at low field strengths is emerging as an exciting direction in perinatal health. Clinical low field (0.55T) scanners are beneficial for fetal imaging due to their reduced susceptibility-induced artefacts, increased T2* values, and wider bore (widening access for the increasingly obese pregnant population). However, the lack of standard automated image processing tools such as segmentation and reconstruction hampers wider clinical use. In this study, we introduce a semi-automatic pipeline using quantitative MRI for the fetal body at low field strength resulting in fast and detailed quantitative T2* relaxometry analysis of all major fetal body organs. Multi-echo dynamic sequences of the fetal body were acquired and reconstructed into a single high-resolution volume using deformable slice-to-volume reconstruction, generating both structural and quantitative T2* 3D volumes. A neural network trained using a semi-supervised approach was created to automatically segment these fetal body 3D volumes into ten different organs (resulting in dice values > 0.74 for 8 out of 10 organs). The T2* values revealed a strong relationship with GA in the lungs, liver, and kidney parenchyma (R^2>0.5). This pipeline was used successfully for a wide range of GAs (17-40 weeks), and is robust to motion artefacts. Low field fetal MRI can be used to perform advanced MRI analysis, and is a viable option for clinical scanning.