We propose to develop a thermoacoustic computed tomography (TCT) scanner for localizing optical-dye-labeled molecular probes in laboratory mice in vivo. This device offers two significant improvements over fluorescence intensity measurements: 1. Fully three-dimensional images will be acquired using a single axial scan of a novel, cylindrical detector army. 2. Exogenous molecular probes, to which a cyanine dye has been attached, will be detected using a dual-wavelength imaging approach. In Phase I we intend to quantify the spatial resolution and low contrast detection limitations of a TCT device that incorporates a 128-element, cylindrical transducer array. These studies will be carried out in tissue-mimicking phantoms, and the results compared to those we have acquired using a TCT device that incorporates a conventional, linear transducer array. We will employ a dual-wavelength, differential-measurement technique for isolating two non-tumor specific carbocyanine dyes (indocyanine dye and cypate), and a tumor-specific optical imaging agent (cytate) with peak absorption at 790 nm. These probes have high extinction coefficient (> 150,000 M-1 cm-1) and low fluorescence quantum yield (<20%), characteristics that favor thermoacoustic imaging. Our goals are to: 1. achieve < 0.5-mm high-contrast, spatial resolution in three dimensions, and 2. image a dye concentration of < 100 nM with a signal-to-noise ratio (SNR) of > 5 within a 1 mm3 volume (100 fmoles) embedded in a tissue-mimicking phantom. In Phase II we will construct a prototype TCT scanner and site the device at the Optical Radiology Laboratory, Washington University, St. Louis, MO. There, researchers will utilize novel monomolecular multimodal imaging agents to compare the imaging capabilities of this TCT scanner to a commercial mu-PET scanner and conventional fluorescence intensity imaging system in a series of phantom and in vivo mouse-imaging experiments.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Small Business Innovation Research Grants (SBIR) - Phase II (R44)
Project #
1R44CA102891-01
Application #
6684838
Study Section
Special Emphasis Panel (ZRG1-SRB (52))
Program Officer
Croft, Barbara
Project Start
2003-08-01
Project End
2003-12-31
Budget Start
2003-08-01
Budget End
2003-12-31
Support Year
1
Fiscal Year
2003
Total Cost
$145,640
Indirect Cost
Name
Optosonics, Inc.
Department
Type
DUNS #
929665875
City
Oriental
State
NC
Country
United States
Zip Code
28571
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Cao, Ning; Cao, Minsong; Chin-Sinex, Helen et al. (2014) Monitoring the effects of anti-angiogenesis on the radiation sensitivity of pancreatic cancer xenografts using dynamic contrast-enhanced computed tomography. Int J Radiat Oncol Biol Phys 88:412-8