Mohebbi Maryam, Reeves Jack A, Jakimovski Dejan, Bartnik Alexander, Bergsland Niels, Salman Fahad, Schweser Ferdinand, Weinstock-Guttman Bianca, Zivadinov Robert, Dwyer Michael G
From the Buffalo Neuroimaging Analysis Center (M.M., J.A.R., D.J., A.B., N.B., F.Salman, F.Schweser, R.Z., M.G.D.), Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York.
Center for Biomedical Imaging at the Clinical Translational Science Institute (F.Schweser, R.Z.), University at Buffalo, State University of New York, Buffalo, New York.
AJNR Am J Neuroradiol. 2025 Mar 4;46(3):611-619. doi: 10.3174/ajnr.A8524.
Paramagnetic rim lesions (PRLs) are an imaging biomarker of chronic inflammation in MS that are associated with more aggressive disease. However, the precise tissue characteristics and extent of their damage, particularly with regard to connected axonal tracts, are incompletely understood. Quantitative diffusion tissue measurements and fiber tractography can provide a more complete picture of these phenomena.
One hundred fifteen people with MS were enrolled in this study. Quantitative susceptibility mapping and DWI were acquired on a 3T MRI scanner. PRLs were identified in 49 (43%) subjects. Diffusion tractography was then used to identify nearby PRL-connected versus non-PRL connected tracts and PRL-connected versus nonconnected surrounding tracts. DWI metrics, including fractional anisotropy (FA), quantitative anisotropy (QA), mean diffusivity, axial diffusivity, radial diffusivity, isotropy, and restricted diffusion imaging, were compared between these tracts and within PRLs and non-PRL lesions themselves.
Tissue within PRLs had significantly lower FA than tissue within non-PRL T2 lesions ( = .04). Tracts connected to PRLs exhibited significantly lower FA ( < .001), higher restricted diffusion imaging ( = .02, and higher Iso values ( = .007) than tracts connected to non-PRL T2 lesions. Only QA was different between tracts connected to PRLs and nonconnected surrounding tracts ( = .003).
PRLs are more destructive both within themselves and to surrounding tissue. This damage appears more spatially than axonally mediated.
顺磁性边缘病变（PRLs）是多发性硬化症（MS）慢性炎症的一种影像学生物标志物，与更具侵袭性的疾病相关。然而，其确切的组织特征和损伤程度，尤其是关于相连轴突束方面，尚未完全明确。定量扩散组织测量和纤维束成像可以更全面地呈现这些现象。
115名MS患者纳入本研究。在3T磁共振成像（MRI）扫描仪上进行定量磁化率成像和扩散加权成像（DWI）。49名（43%）受试者中发现了PRLs。然后使用扩散纤维束成像来识别附近与PRL相连和不相连的纤维束，以及与PRL相连和不相连的周围纤维束。比较这些纤维束之间以及PRL内部和非PRL病变本身的DWI指标，包括分数各向异性（FA）、定量各向异性（QA）、平均扩散率、轴向扩散率、径向扩散率、各向同性和受限扩散成像。
PRL内的组织FA显著低于非PRL T2病变内的组织（P = 0.04）。与PRL相连的纤维束FA显著更低（P < 0.001），受限扩散成像更高（P = 0.02），各向同性值更高（P = 0.007），与连接非PRL T2病变的纤维束相比。仅QA在与PRL相连的纤维束和不相连的周围纤维束之间存在差异（P = 0.003）。
PRLs本身及其对周围组织的破坏更大。这种损伤在空间上的表现似乎比轴突介导的更明显。
