In Vivo MRI and Intravital Optical Microscopy of Window Chambers in Mice

A. F. Gmitro, S. Moore, R. Gatenby Department of Radiology, University of Arizona, Tucson, AZ, United States, College of Optical Sciences, University of Arizona, Tucson, AZ, United States, Biomedical Engineering, University of Arizona, Tucson, AZ, United States Introduction: MRI of mouse models is a powerful method of investigation in cancer biology. It is used routinely to study anatomic, physiologic, and functional aspects of tumor growth and tumor microenvironments [1]. Intravital optical microscopic imaging of implanted window chambers in mouse models is another approach for studying tumor microenvironments. It provides a method for direct high resolution imaging of tumors and the tumor-host interface. Optical imaging of window chambers can be used to study the vascular, pH, and oxygen distributions within tumors and surrounding normal tissues [2]. A key issue in both MRI and optical studies of biological properties is validation of methods. Although relative changes can be appreciated it is often difficult to assess the absolute accuracy of quantitative measures of many of the relevant biological parameters. Cross validation of one technique (e.g. MRI) by another (e.g. intravital microscopy) could provide such an assessment. Here we report on the first in vivo experiments to demonstrate the dual imaging modalities of MRI and intravital optical microscopy.