de Crespigny Alex, Bou-Reslan Hani, Nishimura Merry C, Phillips Heidi, Carano Richard A D, D'Arceuil Helen E
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
J Neurosci Methods. 2008 Jun 30;171(2):207-13. doi: 10.1016/j.jneumeth.2008.03.006. Epub 2008 Mar 27.
Magnetic resonance microscopy (microMRI) is becoming an important tool for non-destructive analysis of fixed brain tissue. However, unlike MRI, X-ray computed tomography (CT) scans show little native soft tissue contrast. In this paper, we explored the use of contrast enhanced (brains immersion stained in iodinated CT contrast media) micro-CT (microCT) for high resolution 3D imaging of fixed normal and pathological brains, compared to microMRI and standard histopathology. An optimum iodine concentration of 0.27 M resulted in excellent contrast between gray and white matter in normal brain and a wide range of anatomical structures were identified. In glioma bearing mouse brains, there was clear deliniation of tumor margin which closely matched that seen on histopathology sections. microCT tumor volume was strongly correlated with histopathology volume. Our data suggests that microCT image contrast in the immersion-stained brains is related to axonal density and myelin content. Compared to traditional histopathology, our microCT approach is relatively rapid and less labor intensive. In addition, compared to microMRI, microCT is robust and requires much lower equipment and maintenance costs. For simple measurements, such as tumor volume and non-destructive postmortem brain screening, microCT may prove to be a valuable alternative to standard histopathology or microMRI.
磁共振显微镜(显微MRI)正成为对固定脑组织进行无损分析的重要工具。然而,与MRI不同,X射线计算机断层扫描(CT)几乎没有天然软组织对比度。在本文中,我们探索了使用对比增强(将脑浸泡在碘化CT造影剂中染色)显微CT(microCT)对固定的正常和病理脑进行高分辨率三维成像,并与显微MRI和标准组织病理学进行比较。0.27M的最佳碘浓度在正常脑中产生了灰质和白质之间的出色对比度,并且识别出了广泛的解剖结构。在患有胶质瘤的小鼠脑中,肿瘤边缘清晰可辨,与组织病理学切片上所见密切匹配。microCT肿瘤体积与组织病理学体积高度相关。我们的数据表明,浸泡染色脑中的microCT图像对比度与轴突密度和髓磷脂含量有关。与传统组织病理学相比,我们的microCT方法相对快速且劳动强度较小。此外,与显微MRI相比,microCT坚固耐用,所需的设备和维护成本要低得多。对于简单测量,如肿瘤体积和无损死后脑筛查,microCT可能被证明是标准组织病理学或显微MRI的有价值替代方法。