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PT  - JOURNAL ARTICLE
AU  - Yao, Y.
AU  - Nguyen, T.D.
AU  - Pandya, S.
AU  - Zhang, Y.
AU  - Hurtado Rúa, S.
AU  - Kovanlikaya, I.
AU  - Kuceyeski, A.
AU  - Liu, Z.
AU  - Wang, Y.
AU  - Gauthier, S.A.
TI  - Combining Quantitative Susceptibility Mapping with Automatic Zero Reference (QSM0) and Myelin Water Fraction Imaging to Quantify Iron-Related Myelin Damage in Chronic Active MS Lesions
AID  - 10.3174/ajnr.A5482
DP  - 2018 Feb 01
TA  - American Journal of Neuroradiology
PG  - 303--310
VI  - 39
IP  - 2
4099  - http://www.ajnr.org/content/39/2/303.short
4100  - http://www.ajnr.org/content/39/2/303.full
SO  - Am. J. Neuroradiol.2018 Feb 01; 39
AB  - BACKGROUND AND PURPOSE: A hyperintense rim on susceptibility in chronic MS lesions is consistent with iron deposition, and the purpose of this study was to quantify iron-related myelin damage within these lesions as compared with those without rim.MATERIALS AND METHODS: Forty-six patients had 2 longitudinal quantitative susceptibility mapping with automatic zero reference scans with a mean interval of 28.9 ± 11.4 months. Myelin water fraction mapping by using fast acquisition with spiral trajectory and T2 prep was obtained at the second time point to measure myelin damage. Mixed-effects models were used to assess lesion quantitative susceptibility mapping and myelin water fraction values.RESULTS: Quantitative susceptibility mapping scans were on average 6.8 parts per billion higher in 116 rim-positive lesions compared with 441 rim-negative lesions (P &amp;lt; .001). All rim-positive lesions retained a hyperintense rim over time, with increasing quantitative susceptibility mapping values of both the rim and core regions (P &amp;lt; .001). Quantitative susceptibility mapping scans and myelin water fraction in rim-positive lesions decreased from rim to core, which is consistent with rim iron deposition. Whole lesion myelin water fractions for rim-positive and rim-negative lesions were 0.055 ± 0.07 and 0.066 ± 0.04, respectively. In the mixed-effects model, rim-positive lesions had on average 0.01 lower myelin water fraction compared with rim-negative lesions (P &amp;lt; .001). The volume of the rim at the initial quantitative susceptibility mapping scan was negatively associated with follow-up myelin water fraction (P &amp;lt; .01).CONCLUSIONS: Quantitative susceptibility mapping rim-positive lesions maintained a hyperintense rim, increased in susceptibility, and had more myelin damage compared with rim-negative lesions. Our results are consistent with the identification of chronic active MS lesions and may provide a target for therapeutic interventions to reduce myelin damage.FAST-T2fast acquisition with spiral trajectory and T2-prepGREgradient-echoMWFmyelin water fractionppbparts per billionQSMquantitative susceptibility mappingQSM0QSM with automatic uniform CSF zero referencerim−rim-negativerim+rim-positive