Photoacoustic Imaging
Photoacoustic tomography (PAT) presents a new non-invasive imaging modality that has great potential in medical applications, most promising in early stage breast cancer diagnostics and imaging of small animals The principle of photoacoustic tomography is the so called photoacoustic effect which is based on a conversion of light energy into acoustic waves. For medical applications acoustic waves are generated inside tissue by stimulating it with short laser pulses which cause acoustic waves. The acoustic waves are then measured outside of the tissue and converted (using mathematical algorithms) into a three dimensional image.
Differently to the main approach, in this project integrals of the acoustic waves over planes [1], lines [2], [3], and recently over circles [4] are used for imaging. Circular and linear detectors, for example, can be realized by a laser beam that is guided along a circle or a line in an optical fiber in some kind of an interferometric set-up. The advantage of this technique is that it leads to images with high resolution and high contrast due to the high measurement accuracy of integrating detectors.
References
- [1] M. Haltmeier, O. Scherzer, P. Burgholzer, and G. Paltauf. Thermoacoustic computed tomography with large planar receivers. Inverse Problems 20(5):1663-1673 (2004).
- [2] P. Burgholzer, C. Hofer, G. Paltauf, M. Haltmeier, and O.Scherzer. Thermoacoustic tomography with integrating area and line detectors. IEEE Trans. on Ultras. Ferroel. and Frequ. Control 52(9): 1577- 1583 (2005).
- [3] M. Haltmeier, O.Scherzer , P. Burgholzer, R. Nuster, and G. Paltauf. Thermoacoustic tomography and the circular Radon transform. Math. Model. Appl. Sci. 17(4): 635-655 (2007).
- [4] Zangerl, G. and Haltmeier, M. and Scherzer, O. Exact Series Reconstruction in Photoacoustic Tomography with Circular Integrating Detectors. Commun. Math. Sci.7(3):665–678 (2009).
Contributors
Markus Haltmeier, Otmar Scherzer, Gerhard Zangerl
Links
- Homepage of our national research network on photoacoustic imaging.
- Photoacoustic tomography on Wikipedia.