Epub: Tardif et al. Quantitative magnetic resonance imaging of cortical multiple sclerosis pathology. Mult Scler Int. 2012;2012:742018. doi: 10.1155/2012/742018. Epub 2012 Nov.
Although significant improvements have been made regarding the visualization and characterization of cortical multiple sclerosis
(MS) lesions using magnetic resonance imaging (MRI), cortical lesions
(CL) continue to be under-detected in vivo, and we have a limited
understanding of the causes of GM pathology. The objective of this study
was to characterize the MRI signature of CLs to help interpret the
changes seen in vivo and elucidate the factors limiting their
visualization. A quantitative 3D high-resolution (350 μm isotropic) MRI
study at 3 Tesla of a fixed post mortem cerebral hemisphere from a
patient with MS is presented in combination with matched
immunohistochemistry. Type III subpial lesions are characterized by an
increase in T1, T2 and M0, and a decrease in MTR in comparison to the
normal appearing cortex (NAC). All quantitative MR parameters were
associated with cortical GM myelin content, while T1 showed the
strongest correlation. The histogram analysis showed extensive overlap
between CL and NAC for all MR parameters and myelin content. This is due
to the poor contrast in myelin content between CL and NAC in comparison
to the variability in myelo-architecture throughout the healthy cortex.
This latter comparison is highlighted by the representation of T1 times
on cortical surfaces at several laminar depths.
Grey mattter lesions have gone undetected for many years, by the grey matter imaging may be key to developing neuroprotecrtive treatments.