Towards very high resolution imaging in ultrasound-modulated optical tomography of biological tissues

Abstract

We explored the possibility of applying very high ultrasound frequencies to achieve very high resolution in ultrasound-modulated optical tomography of soft biological tissues. The ultrasound-modulated coherent light that traversed the scattering biological tissue was detected by a long-cavity and a large etendue confocal Fabry- Perot interferometer. We used various focused ultrasound transducers of 15 MHz, 30 MHz, and 50 MHz to obtain two dimensional images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. This technology is complementary to other imaging technologies, such as confocal microscopy and optical-coherence tomography, and has potential for broad biomedical applications