Free-space fluorescence molecular tomography utilizing 360° geometry projections

Abstract

Fluorescence tomography of diffuse media can yield optimal three-dimensional imaging when multiple projections over 360 degrees geometries are captured, compared with limited projection angle systems such as implementations in the slab geometry. We demonstrate how it is possible to perform noncontact, 360 degrees projection fluorescence tomography of mice using CCD-camera-based detection in free space, i.e., in the absence of matching fluids. This approach achieves high spatial sampling of photons propagating through tissue and yields a superior information content data set compared with fiber-based 360 degrees implementations. Reconstruction feasibility using 36 projections in 10 degrees steps is demonstrated in mice.

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

“…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.…”

Computed Tomography-guided Time-domain Diffuse Fluorescence Tomography in Small Animals for Localization of Cancer Biomarkers

“…At present, there are two competing approaches to FT system design. The most common design is based on cooled charge-coupled device (CCD) cameras for fluorescence detection [4][5][6][7][8][9] . This design provides a high density of measurements, maximizing tissue sampling since each pixel in the CCD camera can detect light that has traveled a unique path through the tissue.…”

“…The majority of research groups have invested in charge-coupled device (CCD)-based systems that provide abundant tissue-sampling but suboptimal sensitivity [4][5][6][7][8][9] , while our group and a few others [10][11][12][13] have pursued systems based on very high sensitivity detectors, that at this time allow dense tissue sampling to be achieved only at the cost of low imaging throughput. Here we demonstrate the methodology for applying single-photon detection technology in a fluorescence tomography system to localize a cancerous brain lesion in a mouse model.…”

Spectral distortion in diffuse molecular luminescence tomography in turbid media

“…9,10 Extracting meaningful spectroscopic measurements or accurate images of the luminescent activity in tissue requires accurate light transport modeling, which, through substantial growth since the early 1990s, 11 has become fairly mature field of research. While fluorescence molecular imaging and spectroscopy systems for use in small animals 4,10,[12][13][14][15][16] have evolved to the point of commercial availability and clinical trials in humans are underway, 17 some of the more subtle complexities of the signal acquisition remain to be examined. One important consideration that has not been investigated in detail, especially in the near-infrared ͑NIR͒, is the interaction between the remission spectrum of the reporter and the intervening tissue through which the light transport occurs prior to detection.…”