Quantitative measurement of tissue optical absorption spectrum in a scattering medium by photoacoustic technique

The photoacoustic technique can be used to quantify tissue absorption spectrum in a wide spectral range from visible to near infrared. As the photoacoustic signal intensity is proportional to tissue optical absorption coefficient and light fluence, it is important to know the local light fluence at the regional target in order to obtain the accurate absorption spectrum because the tissue optical properties including scattering and absorption are wavelength dependent and affect the distribution and intensity of light in the sample. In this work, an optical contrast agent has been employed to enhance the performance of spectroscopic photoacoustic technique. From the photoacoustic measurements with and without the contrast agent in a target tissue, the spectroscopic local light fluence in the tissue can be determined. Then a quantified measurement of the tissue optical absorption spectrum can be realized in a strong scattering medium without need to know the wavelength-dependent optical properties in the scattering medium. A commercially available dye which has strong absorption in the wavelength range of interest was used. The results of the spectroscopic photoacoustic measurements on fresh canine blood specimens in scattering media such as milk and chicken breast tissue have been presented. It was found that photoacoustic measurements after employing this new technique have an improved match with the standard absorption spectra of both oxygenated and deoxygenated blood.

[1]  Lihong V. Wang,et al.  Functional photoacoustic microscopy for high-resolution and noninvasive in vivo imaging , 2006, Nature Biotechnology.

[2]  Robert A. Kruger,et al.  Thermoacoustic Molecular Imaging of Small Animals , 2003 .

[3]  D. Prough,et al.  Multiwavelength optoacoustic system for noninvasive monitoring of cerebral venous oxygenation: a pilot clinical test in the internal jugular vein. , 2006, Optics letters.

[4]  F. D. de Mul,et al.  Three-dimensional photoacoustic imaging of blood vessels in tissue. , 1998, Optics letters.

[5]  Geng Ku,et al.  Noninvasive photoacoustic angiography of animal brains in vivo with near-infrared light and an optical contrast agent. , 2004, Optics letters.

[6]  Roy G. M. Kolkman,et al.  In vivo photoacoustic imaging of blood vessels using an extreme-narrow aperture sensor , 2003 .

[7]  Geng Ku,et al.  Noninvasive imaging of hemoglobin concentration and oxygenation in the rat brain using high-resolution photoacoustic tomography. , 2006, Journal of biomedical optics.

[8]  R. Kruger,et al.  Photoacoustic ultrasound (PAUS)--reconstruction tomography. , 1995, Medical physics.

[9]  Lihong V. Wang,et al.  In vivo imaging and characterization of hypoxia-induced neovascularization and tumor invasion. , 2007, International journal of oncology.

[10]  Lihong V. Wang,et al.  Effects of wavelength-dependent fluence attenuation on the noninvasive photoacoustic imaging of hemoglobin oxygen saturation in subcutaneous vasculature in vivo , 2007 .

[11]  Xueding Wang,et al.  Noninvasive photoacoustic tomography of human peripheral joints toward diagnosis of inflammatory arthritis. , 2007, Optics letters.

[12]  Xu Xiao.  Photoacoustic imaging in biomedicine , 2008 .

[13]  Lihong V. Wang,et al.  Photoacoustic tomography of a nanoshell contrast agent in the in vivo rat brain , 2004 .

[14]  Bo Liu,et al.  Photoacoustic spectroscopic imaging of intra-tumor heterogeneity and molecular identification , 2006, SPIE BiOS.

[15]  Lihong V. Wang,et al.  Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain , 2003, Nature Biotechnology.

[16]  R. Myllylä,et al.  The effects of optical scattering on pulsed photoacoustic measurement in weakly absorbing liquids , 2001 .

[17]  T. Goulet,et al.  Time-gated transillumination of objects in highly scattering media using a subpicosecond optical amplifier , 1999 .

[18]  Hao Zhang,et al.  Imaging of hemoglobin oxygen saturation variations in single vessels in vivo using photoacoustic microscopy , 2007 .

[19]  Lihong V. Wang,et al.  Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels , 2007, Physics in medicine and biology.

[20]  Jan Laufer,et al.  Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration , 2007, Physics in medicine and biology.

[21]  Risto Myllylä,et al.  Scattering photoacoustic study of weakly-absorbing substances in aqueous suspensions , 2006 .