Progressive iron accumulation across multiple sclerosis phenotypes revealed by sparse classification of deep gray matter

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dc.contributor.authorElkady, Ahmed M.
dc.contributor.authorCobzas, Dana
dc.contributor.authorSun, Hongfu
dc.contributor.authorBlevins, Gregg
dc.contributor.authorWilman, Alan H.
dc.date.accessioned2020-10-05
dc.date.accessioned2022-05-31T01:15:24Z
dc.date.available2022-05-31T01:15:24Z
dc.date.issued2017
dc.description.abstractPurpose: To create an automated framework for localized analysis of deep gray matter (DGM) iron accumulation and demyelination using sparse classification by combining quantitative susceptibility (QS) and transverse relaxation rate (R2*) maps, for evaluation of DGM in multiple sclerosis (MS) phenotypes relative to healthy controls. Materials and Methods: R2*/QS maps were computed using a 4.7T 10-echo gradient echo acquisition from 16 clinically isolated syndrome (CIS), 41 relapsing-remitting (RR), 40 secondary-progressive (SP), 13 primary-progressive (PP) MS patients, and 75 controls. Sparse classification for R2*/QS maps of segmented caudate nucleus (CN), putamen (PU), thalamus (TH), and globus pallidus (GP) structures produced localized maps of iron/myelin in MS patients relative to controls. Paired t-tests, with age as a covariate, were used to test for statistical significance (P ≤ 0.05).Results: In addition to DGM structures found significantly different in patients compared to controls using whole region analysis, singular sparse analysis found significant results in RRMS PU R2* (P = 0.03), TH R2* (P = 0.04), CN QS (P = 0.04); in SPMS CN R2* (P = 0.04), GP R2* (P = 0.05); and in PPMS CN R2* (P = 0.04), TH QS (P = 0.04). All sparse regions were found to conform to an iron accumulation pattern of changes in R2*/QS, while none conformed to demyelination. Intersection of sparse R2*/QS regions also resulted in RRMS CN R2* becoming significant, while RRMS R2* TH and PPMS QS TH becoming insignificant. Common iron-associated volumes in MS patients and their effect size progressively increased with advanced phenotypes. Conclusion: A localized technique for identifying sparse regions indicative of iron or myelin in the DGM was developed. Progressive iron accumulation with advanced MS phenotypes was demonstrated, as indicated by iron-associated sparsity and effect size.
dc.description.urihttps://library.macewan.ca/full-record/rzh/125686848
dc.identifier.citationAhmed Elkady, Dana Cobzas, Hongfu Sun, Gregg Blevins, Alan Wilman Progressive Iron Accumulation in Multiple Sclerosis Phenotypes Revealed by Sparse Classification of Deep Gray Matter ISMRM 2017
dc.identifier.doihttps://doi.org/10.1002/jmri.25682
dc.identifier.urihttps://hdl.handle.net/20.500.14078/1764
dc.languageEnglish
dc.language.isoen
dc.rightsAll Rights Reserved
dc.subjectquantitative susceptibility mapping
dc.subjectdeep gray matter
dc.subjectmultiple sclerosis
dc.subjectsparse classification
dc.subjectbrain iron
dc.subjectR2*
dc.titleProgressive iron accumulation across multiple sclerosis phenotypes revealed by sparse classification of deep gray matter
dc.typePresentation
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