Hannoun Salem, Kocevar Gabriel, Codjia Pekes, Barile Berardino, Cotton Francois, Durand-Dubief Francoise, Sappey-Marinier Dominique
Medical Imaging Sciences Program, Division of Health Professions, Faculty of Health Sciences, American University of Beirut, Beirut, Lebanon.
CREATIS, UMR 5220 CNRS & U1294 INSERM, Université Claude Bernard - Lyon1, Université de Lyon, Villeurbanne, France.
J Neuroimaging. 2022 Mar;32(2):328-336. doi: 10.1111/jon.12943. Epub 2021 Nov 9.
The aim of this study is to determine whether cerebral white matter (WM) microstructural damage, defined by decreased fractional anisotropy (FA) and increased axial (AD) and radial (RD) diffusivities, could be detected as accurately by measuring the T1/T2 ratio, in relapsing-remitting multiple sclerosis (RRMS) patients compared to healthy control (HC) subjects.
Twenty-eight RRMS patients and 24 HC subjects were included in this study. Region-based analysis based on the ICBM-81 diffusion tensor imaging (DTI) atlas WM labels was performed to compare T1/T2 ratio to DTI values in normal-appearing WM (NAWM) regions of interest. Lesions segmentation was also performed and compared to the HC global WM.
A significant 19.65% decrease of T1/T2 ratio values was observed in NAWM regions of RRMS patients compared to HC. A significant 6.30% decrease of FA, as well as significant 4.76% and 10.27% increases of AD and RD, respectively, were observed in RRMS compared to the HC group in various NAWM regions. Compared to the global WM HC mask, lesions have significantly decreased T1/T2 ratio and FA and increased AD and RD (p < . 001).
Results showed significant differences between RRMS and HC in both DTI and T1/T2 ratio measurements. T1/T2 ratio even demonstrated extensive WM abnormalities when compared to DTI, thereby highlighting the ratio's sensitivity to subtle differences in cerebral WM structural integrity using only conventional MRI sequences.
本研究旨在确定在复发缓解型多发性硬化症（RRMS）患者与健康对照（HC）受试者中，通过测量T1/T2比值能否像测量分数各向异性（FA）降低以及轴向（AD）和径向（RD）扩散率增加所定义的那样，准确检测到脑白质（WM）微观结构损伤。
本研究纳入了28例RRMS患者和24例HC受试者。基于ICBM - 81扩散张量成像（DTI）图谱WM标签进行基于区域的分析，以比较感兴趣的正常外观白质（NAWM）区域中T1/T2比值与DTI值。还进行了病变分割并与HC全脑白质进行比较。
与HC相比，RRMS患者NAWM区域的T1/T2比值显著降低了19.65%。与HC组相比，在各个NAWM区域中，RRMS患者的FA显著降低了6.30%，AD和RD分别显著增加了4.76%和10.27%。与全脑白质HC模板相比，病变的T1/T2比值和FA显著降低，AD和RD增加（p <.001）。
结果表明，RRMS患者与HC在DTI和T1/T2比值测量方面均存在显著差异。与DTI相比，T1/T2比值甚至显示出广泛的白质异常，从而突出了该比值仅使用传统MRI序列对脑白质结构完整性细微差异的敏感性。
