This study from Canada evaluated four MR imaging methods based on transverse relaxation (T2 weighted, 2 mapping, and R2* mapping) and phase imaging, for measuring iron in subcortical grey matter and for detecting iron within and surrounding MS lesions.
The imaging was performed in three in-situ post-mortem patients with MS less than 28 hours after death and in one in vivo patient one year before death. Results showed that R2* mapping had the highest correlation with iron staining in subcortical grey matter. R2 mapping, phase imaging and T2-weighted imaging had lower but still strong correlations with ironing staining.
Within lesions, hypointense areas did not always represent iron, and can result from demyelination. Hyperintense rims around MS lesions on R2* maps were only present in iron-staining lesions, yet not all iron-staining lesions had R2* rim hyperintensity.
In conclusion, subcortical grey matter iron status could be used with these four MR imaging methods with R2* mapping being preferred, however a reliable method for determining iron status in MS lesions was not established.
Authors: Walsh AJ, Lebel RM, Eissa A
Source: Radiology. 2013 Jan 7. [Epub ahead of print]
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