Abstract
Optical contrast agents, such as indocyanine dyes, nano-particles and their functional derivatives, have been widely applied to enhance the sensitivity and specificity of optical imaging. However, due to the overwhelming scattering of light in biological tissues, the spatial resolution of traditional optical imaging degrades drastically as the imaging depth increases. For the first time to our knowledge, non-invasive in vivo photoacoustic imaging of an optical contrast agent, distributed in the rat brain, was implemented with near-infrared light. Injection of indocyanine green polyethylene glycol, a contrast agent with a high absorption at the 805-nm wavelength, into the circulatory system of a rat enhanced the absorption contrast between the blood vessels and the background brain tissues. Because near-infrared light can penetrate deep into the brain tissues through the skin and skull, we were able to successfully reconstruct the vascular distribution in the rat brain from the detected photoacoustic signals. The dynamic concentration of this contrast agent in the brain blood after the intravenous injection was also studied. This work proved that the distribution of an exogenous contrast agent in biological tissues can be imaged clearly and accurately by photoacoustic tomography. This new technology has high potential for application in dynamic and molecular medical imaging.
Original language | English (US) |
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Article number | 12 |
Pages (from-to) | 77-82 |
Number of pages | 6 |
Journal | Progress in Biomedical Optics and Imaging - Proceedings of SPIE |
Volume | 5 |
Issue number | 9 |
DOIs | |
State | Published - 2004 |
Event | Photons Plus Ultrasound: Imaging and Sensing - San Jose, CA, United States Duration: Jan 25 2004 → Jan 26 2004 |
Keywords
- Contrast agent
- Indocyanine green
- Near-infrared light
- Neuroimaging
- Photoacoustic tomography
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Atomic and Molecular Physics, and Optics
- Radiology Nuclear Medicine and imaging