Tardif Christine L, Bedell Barry J, Eskildsen Simon F, Collins D Louis, Pike G Bruce
McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, Canada.
Mult Scler Int. 2012;2012:742018. doi: 10.1155/2012/742018. Epub 2012 Nov 18.
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.
尽管在利用磁共振成像（MRI）对皮质多发性硬化（MS）病变进行可视化和特征描述方面已取得显著进展，但皮质病变（CL）在活体中仍未得到充分检测，而且我们对灰质病理学的病因了解有限。本研究的目的是描述CL的MRI特征，以帮助解释活体中观察到的变化，并阐明限制其可视化的因素。本文介绍了一项针对一名MS患者的固定死后大脑半球在3特斯拉下进行的定量三维高分辨率（各向同性350μm）MRI研究，并结合了匹配的免疫组织化学分析。与正常外观皮质（NAC）相比，III型软膜下病变的特征是T1、T2和M0增加，MTR降低。所有定量MR参数均与皮质灰质髓鞘含量相关，而T1显示出最强的相关性。直方图分析表明，CL和NAC在所有MR参数和髓鞘含量方面存在广泛重叠。这是因为与整个健康皮质中髓鞘结构的变异性相比，CL和NAC之间的髓鞘含量对比度较差。通过在几个层深的皮质表面上表示T1时间突出了后一种比较。
