Experimental Fluorescence Tomography of Tissues With Noncontact Measurements

Abstract

Noncontact optical measurements from diffuse media could facilitate the use of large detector arrays at multiple angles that are well suited for diffuse optical tomography applications. Such imaging strategy could eliminate the need for individual fibers in contact with tissue, restricted geometries, and matching fluids. Thus, it could significantly improve experimental procedures and enhance our ability to visualize functional and molecular processes in vivo. In this paper, we describe the experimental implementation of this novel concept and demonstrate capacity to perform small animal imaging.

Magnetic resonance–coupled fluorescence tomography scanner for molecular imaging of tissue

“…The diffuse, Gaussian shape of the elevated region is typical of fluorescent molecular tomography imaging without spatial guidance. 3,5,[26][27][28][29][30][31] The use of hard priors, as implemented here, transforms the imaging problem to one of quantification since the recovery of the tumor region size and location is not the ultimate objective. In this case, the tumor region outline is given by a region-growing threshold of the enhanced MR image, and the fluorescence recovery algorithm estimates the fluorescence uptake in that predefined region.…”

“…Given the availability of targeted molecular imaging agents for animal research, several small animal fluorescence tomography scanners have been developed to provide volumetric images of fluorescence activity. [1][2][3][4][5][6] Other studies have focused on the systematic development and assessment of diffuse optical fluorescence tomographic ͑DOFT͒ imaging techniques in tissue volumes relevant to human imaging, if targeted probes earn clinical approval. [7][8][9][10][11] Most previous work involving human breast imaging has been completed using tissue simulating phantoms, though fluorescence tomography images of human breast using the nontargeted fluorophore indocyanine green ͑ICG͒ have very recently been published.…”

Molecular Tomographic Imaging of Lymph Nodes With Nir Fluorescence

“…To alleviate this concern to a degree, the legs of the animal were slightly stretched to create a nearly planar profile on the groin surface. Current work is underway on incorporating a 3D surface capturing camera system [8] with the ICCD detection setup, so that the true animal geometry can also be acquired and used for finite element simulations involved in image reconstruction. Additional improvements needed for clinical translation include the need to co-register the fluorescence images and reconstructed fluorophore maps with white light images of skin surface to ease image interpretation by non-experts, and rectifying the out of focus blur created when nonplanar surfaces are imaged by the CCD camera.…”

Fundamentals of Optical Imaging

“…An important property of optical tomographic systems is whether light coupling is performed using fibers in contact with the imaged object, or whether contact-free detection via an objective lens is implemented (noncontact imaging; Schulz et al 2004). While in fiber-based designs, complex shaped objects have to be embedded in some kind of optically matching fluid as the fiber ends usually cannot be positioned arbitrarily, this is unnecessary for non-contact designs.…”