Xu Xinyi, Sun Cong, Yu Hong, Yan Guohui, Zhu Qingqing, Kong Xianglei, Pan Yibin, Xu Haoan, Zheng Tianshu, Zhou Chi, Wang Yutian, Xiao Jiaxin, Chen Ruike, Li Mingyang, Zhang Songying, Hu Hongjie, Zou Yu, Wang Jingshi, Wang Guangbin, Wu Dan
Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China.
Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China.
Eur Radiol. 2025 Apr;35(4):1830-1842. doi: 10.1007/s00330-024-11084-w. Epub 2024 Sep 19.
To evaluate multisite effects on fetal brain MRI. Specifically, to identify crucial acquisition factors affecting fetal brain structural measurements and developmental patterns, while assessing the effectiveness of existing harmonization methods in mitigating site effects.
Between May 2017 and March 2022, T2-weighted fast spin-echo sequences in-utero MRI were performed on healthy fetuses from retrospectively recruited pregnant volunteers on four different scanners at four sites. A generalized additive model (GAM) was used to quantitatively assess site effects, including field strength (FS), manufacturer (M), in-plane resolution (R), and slice thickness (ST), on subcortical volume and cortical morphological measurements, including cortical thickness, curvature, and sulcal depth. Growth models were selected to elucidate the developmental trajectories of these morphological measurements. Welch's test was performed to evaluate the influence of site effects on developmental trajectories. The comBat-GAM harmonization method was applied to mitigate site-related biases.
The final analytic sample consisted of 340 MRI scans from 218 fetuses (mean GA, 30.1 weeks ± 4.4 [range, 21.7-40 weeks]). GAM results showed that lower FS and lower spatial resolution led to overestimations in selected brain regions of subcortical volumes and cortical morphological measurements. Only the peak cortical thickness in developmental trajectories was significantly influenced by the effects of FS and R. Notably, ComBat-GAM harmonization effectively removed site effects while preserving developmental patterns.
Our findings pinpointed the key acquisition factors in in-utero fetal brain MRI and underscored the necessity of data harmonization when pooling multisite data for fetal brain morphology investigations.
Question How do specific site MRI acquisition factors affect fetal brain imaging? Finding Lower FS and spatial resolution overestimated subcortical volumes and cortical measurements. Cortical thickness in developmental trajectories was influenced by FS and in-plane resolution. Clinical relevance This study provides important guidelines for the fetal MRI community when scanning fetal brains and underscores the necessity of data harmonization of cross-center fetal studies.
评估多中心因素对胎儿脑磁共振成像（MRI）的影响。具体而言，确定影响胎儿脑结构测量和发育模式的关键采集因素，同时评估现有标准化方法在减轻中心间差异方面的有效性。
2017年5月至2022年3月期间，对回顾性招募的孕妇志愿者所怀健康胎儿在四个中心的四台不同扫描仪上进行了子宫内MRI的T2加权快速自旋回波序列扫描。使用广义相加模型（GAM）定量评估场强（FS）、制造商（M）、平面分辨率（R）和层厚（ST）等中心因素对皮质下体积和皮质形态测量（包括皮质厚度、曲率和脑沟深度）的影响。选择生长模型来阐明这些形态测量的发育轨迹。采用韦尔奇检验评估中心因素对发育轨迹的影响。应用ComBat-GAM标准化方法减轻与中心相关的偏差。
最终分析样本包括来自218例胎儿的340次MRI扫描（平均孕周，30.1周±4.4[范围，21.7 - 40周]）。GAM结果显示，较低的场强和较低的空间分辨率导致皮质下体积和皮质形态测量的选定脑区出现高估。在发育轨迹中，仅皮质厚度峰值受场强和分辨率的影响显著。值得注意的是，ComBat-GAM标准化有效地消除了中心因素的影响，同时保留了发育模式。
我们的研究结果确定了子宫内胎儿脑MRI的关键采集因素，并强调了在汇总多中心数据进行胎儿脑形态学研究时进行数据标准化的必要性。
问题特定的中心MRI采集因素如何影响胎儿脑成像？发现较低的场强和空间分辨率高估了皮质下体积和皮质测量值。发育轨迹中的皮质厚度受场强和平面分辨率的影响。临床意义本研究为胎儿MRI领域在扫描胎儿脑时提供了重要指导原则，并强调了跨中心胎儿研究数据标准化的必要性。
