TY - JOUR
T1 - Axonal and myelin changes and their inter-relationship in the optic radiations in people with multiple sclerosis
AU - Krijnen, Eva A.
AU - Ngamsombat, Chanon
AU - George, Ilena C.
AU - Yu, Fang F.
AU - Fan, Qiuyun
AU - Tian, Qiyuan
AU - Huang, Susie Y.
AU - Klawiter, Eric C.
N1 - Funding Information: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National Institutes of Health (grant numbers K23-NS096056, P41-EB015896, P41-EB030006, R01-NS118187, and U01-EB026996) Funding Information: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: I.C.G. became employed by Biogen following her contributions to this research. S.Y.H. has received consulting fees and research grants from Siemens Healthineers. E.C.K. has received consulting fees from Banner Life Sciences, Galen/Atlantica, Genentech, Greenwich Biosciences and OM1, and research funds from Abbvie, Biogen, and Genentech. Other authors report no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Publisher Copyright: © The Author(s), 2023.
PY - 2023/1/1
Y1 - 2023/1/1
N2 - Background: The imaging g-ratio, estimated from axonal volume fraction (AVF) and myelin volume fraction (MVF), is a novel biomarker of microstructural tissue integrity in multiple sclerosis (MS). Objective: To assess axonal and myelin changes and their inter-relationship as measured by g-ratio in the optic radiations (OR) in people with MS (pwMS) with and without previous optic neuritis (ON) compared to healthy controls (HC). Methods: Thirty pwMS and 17 HCs were scanned on a 3Tesla Connectom scanner. AVF and MVF, derived from a multi-shell diffusion protocol and macromolecular tissue volume, respectively, were measured in normal-appearing white matter (NAWM) and lesions within the OR and used to calculate imaging g-ratio. Results: OR AVF and MVF were decreased in pwMS compared to HC, and in OR lesions compared to NAWM, whereas the g-ratio was not different. Compared to pwMS with previous ON, AVF and g-ratio tended to be higher in pwMS without prior ON. AVF and MVF, particularly in NAWM, were positively correlated with retinal thickness, which was more pronounced in pwMS with prior ON. Conclusion: Axonal measures reflect microstructural tissue damage in the OR, particularly in the setting of remote ON, and correlate with established metrics of visual health in MS.
AB - Background: The imaging g-ratio, estimated from axonal volume fraction (AVF) and myelin volume fraction (MVF), is a novel biomarker of microstructural tissue integrity in multiple sclerosis (MS). Objective: To assess axonal and myelin changes and their inter-relationship as measured by g-ratio in the optic radiations (OR) in people with MS (pwMS) with and without previous optic neuritis (ON) compared to healthy controls (HC). Methods: Thirty pwMS and 17 HCs were scanned on a 3Tesla Connectom scanner. AVF and MVF, derived from a multi-shell diffusion protocol and macromolecular tissue volume, respectively, were measured in normal-appearing white matter (NAWM) and lesions within the OR and used to calculate imaging g-ratio. Results: OR AVF and MVF were decreased in pwMS compared to HC, and in OR lesions compared to NAWM, whereas the g-ratio was not different. Compared to pwMS with previous ON, AVF and g-ratio tended to be higher in pwMS without prior ON. AVF and MVF, particularly in NAWM, were positively correlated with retinal thickness, which was more pronounced in pwMS with prior ON. Conclusion: Axonal measures reflect microstructural tissue damage in the OR, particularly in the setting of remote ON, and correlate with established metrics of visual health in MS.
KW - Optic neuritis
KW - diffusion magnetic resonance imaging
KW - diffusion tractography
KW - multiple sclerosis
KW - optical coherence tomography
KW - white matter
UR - http://www.scopus.com/inward/record.url?scp=85148652610&partnerID=8YFLogxK
U2 - https://doi.org/10.1177/20552173221147620
DO - https://doi.org/10.1177/20552173221147620
M3 - Article
C2 - 36814811
SN - 2055-2173
VL - 9
JO - Multiple sclerosis journal - experimental, translational and clinical
JF - Multiple sclerosis journal - experimental, translational and clinical
IS - 1
ER -