DOI: 10.6084/m9.figshare.28122386.v1
title: A domed window chamber for multi-modality optical imaging

description: Current dorsal skin flap window chambers with flat glass windows are compatible with optical coherence tomography (OCT) and multiphoton microscopy (MPM) imaging. However, light sheet fluorescence microscopy (LSFM) performs best with a cylindrical or spherical sample located between its two 90° objectives and when all sample materials have the same index of refraction (<i>n</i>). A modified window chamber with a domed viewing window made from fluorinated ethylene propylene (FEP), with n similar to water and tissue, was designed. <i>In vitro</i> imaging of collagen gels and microsphere phantoms with and without the dome showed small decreases in signal strength and image resolution due to the dome. Using a custom mouse platform for stabilization and anesthesia support, <i>in vivo</i> multimodality imaging with OCT, MPM, and LSFI was demonstrated. Experimental techniques for live tumor imaging have traditionally used flat glass skin window chambers. These windows enable tumor assessment in the natural environment using light-based imaging modalities including optical coherence tomography (OCT) and multiphoton microscopy (MPM), however, they are not compatible with the geometry of light sheet fluorescence microscopy (LSFM). Multi-instrument imaging may improve our ability to characterize and understand tumors. We developed an optically clear plastic dome-shaped window to accommodate LSFM imaging in addition to OCT and MPM since the raised dome fits between the two objectives of the light sheet microscope. The dome-shaped window chamber was tested with microsphere targets to understand the impact of the dome on the image quality of OCT, MPM, and LSFM. It was also implanted onto the skin of live mice with tumors and imaging was demonstrated. The window chamber and a custom-designed mouse imaging platform were compatible with OCT, MPM, and LSFM imaging of live mice. The dome-shaped plastic window caused minor (less than 10%) degradation of the resolution and signal strength in all three imaging modalities. Overall, our experiments confirmed that assessment of live tumors using LSFM imaging, in addition to OCT and MPM imaging, can be made possible by using a dome-shaped window. Window chambers enable the visualization of interior body structure and function in mouse research models. A modified dorsal skin flap window chamber was designed and built, containing an optically clear dome made from fluorinated ethylene propylene (FEP). This window chamber was tested for compatibility and image quality with three optical imaging modalities: optical coherence tomography, multiphoton microscopy, and light sheet fluorescence microscopy. The index of refraction of FEP (similar to water) and the domed shape enabled quality imaging with all three modalities. <i>In vivo</i> imaging was demonstrated using the window chamber installed on a mouse, and facilitated by a custom <i>in vivo</i> imaging fixture, including a window chamber holder and a stable imaging base. A custom domed dorsal skin flap window chamber and custom <i>in vivo</i> imaging fixture were designed and fabricated. Imaging was successfully performed with optical coherence tomography (OCT), multi-photon microscopy (MPM), and light sheet fluorescence microscopy (LSFM) imaging modalities, both <i>in vitro</i> with phantoms, and <i>in vivo</i> with a wild-type mouse.