Prohl Anna K, Scherrer Benoit, Tomas-Fernandez Xavier, Filip-Dhima Rajna, Kapur Kush, Velasco-Annis Clemente, Clancy Sean, Carmody Erin, Dean Meghan, Valle Molly, Prabhu Sanjay P, Peters Jurriaan M, Bebin E Martina, Krueger Darcy A, Northrup Hope, Wu Joyce Y, Sahin Mustafa, Warfield Simon K
Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital, Harvard Medical School, Harvard University, Boston, MA, United States.
Department of Neurology, Boston Children's Hospital, Harvard Medical School, Harvard University, Boston, MA, United States.
Front Integr Neurosci. 2019 Jul 17;13:24. doi: 10.3389/fnint.2019.00024. eCollection 2019.
Multi-site MRI studies are often necessary for recruiting sufficiently sized samples when studying rare conditions. However, they require pooling data from multiple scanners into a single data set, and therefore it is critical to evaluate the variability of quantitative MRI measures within and across scanners used in multi-site studies. The aim of this study was to evaluate the reproducibility of structural and diffusion weighted (DW) MRI measurements acquired on seven scanners at five medical centers as part of the Tuberous Sclerosis Complex Autism Center of Excellence Research Network (TACERN) multisite study.
The American College of Radiology (ACR) phantom was imaged monthly to measure reproducibility of signal intensity and uniformity within and across seven 3T scanners from General Electric, Philips, and Siemens vendors. One healthy adult male volunteer was imaged repeatedly on all seven scanners under the TACERN structural and DW protocol (5 b = 0 s/mm and 30 b = 1000 s/mm) over a period of 5 years (age 22-27 years). Reproducibility of inter- and intra-scanner brain segmentation volumes and diffusion tensor imaging metrics fractional anisotropy (FA) and mean diffusivity (MD) within white matter regions was quantified with coefficient of variation.
The American College of Radiology Phantom signal intensity and uniformity were similar across scanners and changed little over time, with a mean intra-scanner coefficient of variation of 3.6 and 1.8%, respectively. The mean inter- and intra-scanner coefficients of variation of brain structure volumes derived from T1-weighted (T1w) images of the human phantom were 3.3 and 1.1%, respectively. The mean inter- and intra-scanner coefficients of variation of FA in white matter regions were 4.5 and 2.5%, while the mean inter- and intra-scanner coefficients of variation of MD in white matter regions were 5.4 and 1.5%.
Our results suggest that volumetric and diffusion tensor imaging (DTI) measurements are highly reproducible between and within scanners and provide typical variation amplitudes that can be used as references to interpret future findings in the TACERN network.
在研究罕见疾病时，多中心MRI研究通常对于招募足够规模的样本是必要的。然而，它们需要将来自多个扫描仪的数据汇集到一个数据集中，因此评估多中心研究中使用的扫描仪内部和之间定量MRI测量的变异性至关重要。本研究的目的是评估作为结节性硬化症复杂自闭症卓越研究网络（TACERN）多中心研究的一部分，在五个医疗中心的七台扫描仪上获得的结构和扩散加权（DW）MRI测量的可重复性。
每月对美国放射学会（ACR）体模进行成像，以测量来自通用电气、飞利浦和西门子供应商的七台3T扫描仪内部和之间信号强度和均匀性的可重复性。一名健康成年男性志愿者在5年（22至27岁）期间按照TACERN结构和DW协议（5个b = 0 s/mm²和30个b = 1000 s/mm²）在所有七台扫描仪上反复成像。使用变异系数对白质区域内扫描仪间和扫描仪内脑部分割体积以及扩散张量成像指标分数各向异性（FA）和平均扩散率（MD）的可重复性进行量化。
美国放射学会体模的信号强度和均匀性在各扫描仪之间相似，且随时间变化不大，扫描仪内变异系数的平均值分别为3.6%和1.8%。从人体模的T1加权（T1w）图像得出的脑结构体积扫描仪间和扫描仪内变异系数的平均值分别为3.3%和1.1%。白质区域FA的扫描仪间和扫描仪内变异系数的平均值分别为4.5%和2.5%，而白质区域MD的扫描仪间和扫描仪内变异系数的平均值分别为5.4%和l.5%。
我们的结果表明，体积测量和扩散张量成像（DTI）测量在扫描仪之间和内部具有高度可重复性，并提供了典型的变异幅度，可作为解释TACERN网络未来研究结果的参考。
