目的:通过使用开源供应商不可知的Pulseq平台开发供应商中立的dMRI脉冲序列,减少来自不同供应商的扫描仪之间扩散MRI(dMRI)测量的扫描仪间差异。
方法:我们在Pulseq中实施了基于EPI的标准dMRI序列。我们在来自不同供应商(SiemensPrisma和GEPremier)的两台临床扫描仪上进行了测试,系统地评估和比较供应商之间的扫描仪内和扫描仪间差异,使用供应商提供的和PulseqdMRI序列。评估涵盖了扩散模型和三个人类受试者,使用标准误差(SE)和Lin的一致性相关性来测量标准DTI指标的可重复性和再现性,包括分数各向异性(FA)和平均扩散率(MD)。
结果:使用Pulseq在两个扫描仪上执行相同的dMRI序列。在幻影上,Pulseq序列显示,西门子和GE扫描仪的SE(变异性)减少了2.5倍以上。此外,Pulseq序列在体内表现出显著降低的SE,与供应商提供的序列相比,维持扫描-再扫描可重复性,同时降低FA和MD的变异性(皮质/皮质下区域减少50%以上)。
结论:Pulseq扩散序列降低了体模和体内数据的跨扫描仪变异性,这将有利于多中心神经影像学研究,并提高神经影像学研究的可重复性。
OBJECTIVE: To reduce the inter-scanner variability of diffusion MRI (
dMRI) measures between scanners from different vendors by developing a vendor-neutral
dMRI pulse sequence using the open-source vendor-agnostic Pulseq platform.
METHODS: We implemented a standard EPI based
dMRI sequence in Pulseq. We tested it on two clinical scanners from different vendors (Siemens Prisma and GE Premier), systematically evaluating and comparing the within- and inter-scanner variability across the vendors, using both the vendor-provided and Pulseq
dMRI sequences. Assessments covered both a diffusion phantom and three human subjects, using standard error (SE) and Lin\'s concordance correlation to measure the repeatability and reproducibility of standard DTI metrics including fractional anisotropy (FA) and mean diffusivity (MD).
RESULTS: Identical
dMRI sequences were executed on both scanners using Pulseq. On the phantom, the Pulseq sequence showed more than a 2.5× reduction in SE (variability) across Siemens and GE scanners. Furthermore, Pulseq sequences exhibited markedly reduced SE in-vivo, maintaining scan-rescan repeatability while delivering lower variability in FA and MD (more than 50% reduction in cortical/subcortical regions) compared to vendor-provided sequences.
CONCLUSIONS: The Pulseq diffusion sequence reduces the cross-scanner variability for both phantom and in-vivo data, which will benefit multi-center neuroimaging studies and improve the reproducibility of neuroimaging studies.