title: Quantitative Susceptibility Mapping and R2* Measured Changes during White Matter Lesion Development in Multiple Sclerosis: Myelin Breakdown, Myelin Debris Degradation and Removal, and Iron Accumulation.
abstract: Quantitative susceptibility mapping and R2* are sensitive to myelin and iron changes in multiple sclerosis lesions. This study was designed to characterize lesion changes on quantitative susceptibility mapping and R2* at various gadolinium-enhancement stages.
  
  
  
  This study included 64 patients with MS with different enhancing patterns in white matter lesions: nodular, shell-like, nonenhancing < 1 year old, and nonenhancing 1-3 years old. These represent acute, late acute, early chronic, and late chronic lesions, respectively. Susceptibility values measured on quantitative susceptibility mapping and R2* values were compared among the 4 lesion types. Their differences were assessed with a generalized estimating equation, controlling for Expanded Disability Status Scale score, age, and disease duration.
  
  
  
  We analyzed 203 lesions: 80 were nodular-enhancing, of which 77 (96.2%) were isointense on quantitative susceptibility mapping; 33 were shell-enhancing, of which 30 (90.9%) were hyperintense on quantitative susceptibility mapping; and 49 were nonenhancing lesions < 1 year old and 41 were nonenhancing lesions 1-3 years old, all of which were hyperintense on quantitative susceptibility mapping. Their relative susceptibility/R2* values were 0.5 ± 4.4 parts per billion/-5.6 ± 2.9 Hz, 10.2 ± 5.4 parts per billion/-8.0 ± 2.6 Hz, 20.2 ± 7.8 parts per billion/-3.1 ± 2.3 Hz, and 33.2 ± 8.2 parts per billion/-2.0 ± 2.6 Hz, respectively, and were significantly different (P < .005).
  
  
  
  Early active MS lesions with nodular enhancement show R2* decrease but no quantitative susceptibility mapping change, reflecting myelin breakdown; late active lesions with peripheral enhancement show R2* decrease and quantitative susceptibility mapping increase in the lesion center, reflecting further degradation and removal of myelin debris; and early or late chronic nonenhancing lesions show both quantitative susceptibility mapping and R2* increase, reflecting iron accumulation.
authors.affiliation: From the Department of Radiology (Y.Z., W.C., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.).
authors.forename: Y
authors.identifier: 0000-0002-2251-3777
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Neurology (S.A.G.).
authors.forename: S A
authors.identifier: 0000-0002-4015-1781
authors.initials: SA
authors.lastname: Gauthier
authors.affiliation: Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.).
authors.forename: A
authors.identifier: 0000-0003-2816-0340
authors.initials: A
authors.lastname: Gupta
authors.affiliation: From the Department of Radiology (Y.Z., W.C., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: W
authors.identifier: 0000-0001-8014-2364
authors.initials: W
authors.lastname: Chen
authors.affiliation: Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.).
authors.forename: J
authors.identifier: 0000-0001-6063-0109
authors.initials: J
authors.lastname: Comunale
authors.affiliation: Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.).
authors.forename: G C-Y
authors.identifier: 0000-0001-9925-0816
authors.initials: GC
authors.lastname: Chiang
authors.affiliation: Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.).
authors.forename: D
authors.identifier: 0000-0002-5436-6177
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Healthcare Policy and Research (G.A.), Weill Cornell Medical College, New York, New York.
authors.forename: G
authors.identifier: 0000-0001-5126-9809
authors.initials: G
authors.lastname: Askin
authors.affiliation: From the Department of Radiology (Y.Z., W.C., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: W
authors.identifier: 0000-0002-0254-6563
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Neurology (D.P.), School of Medicine, Yale University, New Haven, Connecticut.
authors.forename: D
authors.identifier: 0000-0002-6407-9542
authors.initials: D
authors.lastname: Pitt
authors.affiliation: Departments of Radiology (Y.Z., A.G., J.C., G.C.-Y.C., D.Z., Y.W.) Department of Biomedical Engineering (Y.W.), Cornell University, Ithaca, New York. yiwang@med.cornell.edu.
authors.forename: Y
authors.identifier: 0000-0003-1404-8526
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D009186:Myelin Sheath / Q000473:pathology; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology