HUH-MR Research/Radiology, Wayne State University, Detroit, MI, USA.
Magn Reson Imaging. 2012 Dec;30(10):1416-23. doi: 10.1016/j.mri.2012.04.011. Epub 2012 Jul 11.
A dual imaging approach, combining magnetic resonance imaging to localize lesions and synchrotron rapid scanning X-ray fluorescence (XRF) mapping to localize and quantify calcium, iron and zinc was used to examine one case of recent stroke with hemorrhage and two cases of ischemia 3 and 7 years before death with the latter showing superficial necrosis. In hemorrhagic lesions, more Fe is found accompanied with less Zn. In chronic ischemic lesions, Fe, Zn and Ca are lower indicating that these elements are removed as the normal tissue dies and scar tissue forms. Both susceptibility and T2* maps were calculated to visualize iron in hemorrhages and validated by XRF Ca and Fe maps. The former was superior for imaging iron in hemorrhagic transformation and necrosis but did not capture ischemic lesions. In contrast, T2* could not differentiate Ca from Fe in necrotic tissue but did capture ischemic lesions, complementing the susceptibility mapping. The spatial localization, accurate quantitative data and elemental differentiation shown here could also be valuable for imaging other brain tissue damage with abnormal Ca and Fe content.
采用双模式成像方法，将磁共振成像（MRI）用于定位病变，同步辐射快速扫描 X 射线荧光（XRF）映射用于定位和定量钙、铁和锌，对一例近期伴有出血的中风病例和两例死亡前 3 年和 7 年的缺血性病变进行了检查，后两例显示表浅性坏死。在出血性病变中，发现更多的 Fe 伴随着更少的 Zn。在慢性缺血性病变中，Fe、Zn 和 Ca 水平较低，表明随着正常组织死亡和瘢痕组织形成，这些元素被清除。计算磁敏感和 T2图以可视化出血中的铁，并通过 XRF Ca 和 Fe 图进行验证。前者在显示出血性转化和坏死中的铁方面更具优势，但不能捕获缺血性病变。相比之下，T2不能区分坏死组织中的 Ca 和 Fe，但可以捕获缺血性病变，补充了磁敏感图。这里显示的空间定位、准确的定量数据和元素分化对于成像具有异常 Ca 和 Fe 含量的其他脑组织损伤也可能具有重要价值。
