RT Journal Article
SR Electronic
T1 Diffusion- and Tractography-Based Characterization of Tissue Damage Within and Surrounding Paramagnetic Rim Lesions in Multiple Sclerosis
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 611
OP 619
DO 10.3174/ajnr.A8524
VO 46
IS 3
A1 Mohebbi, Maryam
A1 Reeves, Jack A.
A1 Jakimovski, Dejan
A1 Bartnik, Alexander
A1 Bergsland, Niels
A1 Salman, Fahad
A1 Schweser, Ferdinand
A1 Weinstock-Guttman, Bianca
A1 Zivadinov, Robert
A1 Dwyer, Michael G.
YR 2025
UL http://www.ajnr.org/content/46/3/611.abstract
AB BACKGROUND AND PURPOSE: 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.MATERIALS AND METHODS: 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.RESULTS: Tissue within PRLs had significantly lower FA than tissue within non-PRL T2 lesions (P = .04). Tracts connected to PRLs exhibited significantly lower FA (P < .001), higher restricted diffusion imaging (P = .02, and higher Iso values (P = .007) than tracts connected to non-PRL T2 lesions. Only QA was different between tracts connected to PRLs and nonconnected surrounding tracts (P = .003).CONCLUSIONS: PRLs are more destructive both within themselves and to surrounding tissue. This damage appears more spatially than axonally mediated.ADaxial diffusivityCALchronic active lesionDKIdiffusional kurtosis imagingFAfractional anisotropyFDRfalse discovery rateFLIPflip angleFSLFMRIB’s Software LibraryGQIgeneralized q-sampling imagingIsoisotropyLVlesion volumeMDmean diffusivityPRLparamagnetic rim lesionpwMSpeople with MSQAquantitative anisotropyQSMquantitative susceptibility mappingRDradial diffusivityRDIrestricted diffusion imagingRRMSrelapsing-remitting MSSDFspin distribution functionT1wT1-weighted