This study from Canada looked at the evolution of new MS lesions over time using frequency shifts of the MR signal in 20 people with relapsing-remitting MS, serially scanned at monthly intervals every six months.
They acquired maps of the MR frequency shifts using susceptibility-weighted imaging. Gadolinium enhancement was used to identify new lesions. They found that 40 new lesions were identified as areas of increased signal on gadolinium-enhanced scans. There was a rapid increase in MR frequency seen between one month before and one month after Gd enhancement. There was no difference in the frequency up to three months before lesion appearance in areas of future Gd enhancement when compared to normal appearing white matter. The frequency stabilised two months post the enhancement and remained at a constantly increased level.
The researchers think that the increase in MR frequency reflects a change of tissue architecture due to new lesion formation. This imaging technique can be rapidly acquired and standardised on most clinical scanners.
Authors: Wiggermann V, Hernández Torres E
Source: Neurology. 2013 Jun 12. [Epub ahead of print]
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