一种分析活的动物体内生化异常的新方法有可能让科学家检查肿瘤和周围组织，这可以用于观察一种癌症的进展。靶向荧光分子已经被证明对于显示蛋白质、分子路径和区分健康及患病组织极为有用。同样地，全动物和临床尺度的荧光断层成像技术为研究活体的整个器官和疾病发展提供了极大的前景。然而，这项技术的临床使用受到了限制，因为光子和生物组织相互作用的时候光线会被散射，这从根本上模糊了重建后的图像并让重要的特征难以分辨。
Mark Niedre及其同事发现了一种技术，它可以通过利用来自高速脉冲激光源的最早到达而被散射最少的光子，从而减少了散射效应。这组科学家应用这种“早期光子断层成像”技术显示小鼠的肺部肿瘤，他们在小鼠的肺部发现了肿瘤和邻近组织的变化，因而揭示出了活动物细胞和分子层次的变化。相关论文发表在美国《国家科学院院刊》（PNAS）上。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS，doi: 10.1073/pnas.0804798105，Mark J. Niedre，Vasilis Ntziachristos
Early photon tomography allows fluorescence detection of lung carcinomas and disease progression in mice in vivo
Mark J. Niedrea,b, Ruben H. de Kleinea, Elena Aikawaa, David G. Kirscha,c, Ralph Weissledera, and Vasilis Ntziachristosa,d,1
aCenter for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129;
bDepartment of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115;
cDepartment of Radiation Oncology, Duke University, Durham, NC 27710; and
dInstitute for Biological and Medical Imaging, Technical University of Munich and Helmholtz Center Munich, Ismaningerstrasse 21, D-85764 Munich, Germany
Edited by Britton Chance, University of Pennsylvania School of Medicine, Philadelphia, PA, and approved October 7, 2008 (received for review May 16, 2008)
Abstract
Imaging of targeted fluorescent probes offers significant advantages for investigating disease and tissue function in animal models in vivo. Conversely, macroscopic tomographic imaging is challenging because of the high scatter of light in biological tissue and the ill-posed nature of the reconstruction mathematics. In this work, we use the earliest-transmitted photons through Lewis Lung Carcinoma bearing mice, thereby dramatically reducing the effect of tissue scattering. By using a fluorescent probe sensitive to cysteine proteases, the method yielded outstanding imaging performance compared with conventional approaches. Accurate visualization of biochemical abnormalities was achieved, not only in the primary tumor, but also in the surrounding tissue related to cancer progression and inflammatory response at the organ level. These findings were confirmed histologically and with ex vivo fluorescence microscopy. The imaging fidelity demonstrated underscores a method that can use a wide range of fluorescent probes to accurately visualize cellular- and molecular-level events in whole animals in vivo.
