This pilot study takes the innovative approach of using ultrasmall superparamagnetic iron
oxide (USPIO) nanoparticle enhanced MRI to measure activity of the innate immune system
within MS lesions. Activity of innate immunity has been hypothesized as one of the critical
pathologic processes underpinning neurologic worsening in progressive MS. As such, in the
short term this project proposes to investigate USPIO uptake in SPMS lesions as a promising
in vivo imaging biomarker for chronic-active lesions, as distinguished from chronic-inactive
lesions.