Optoacoustic Tomography enables the acquisition of images based on optical contrast with a spatial resolution and penetration depth approaching that of ultrasound. Absorption of a nanosecond laser pulse by tissue generates a thermoelastic expansion and results in a detectable ultrasound wave. Emerging evidence suggests that Multi Spectral Optoacoustic Tomography (MSOT), referring to optoacoustic tomography performed at multiple wavelengths, can assess tissue vascular function without the need for injectable contrast. The differential optical absorption of oxy- and deoxy-haemoglobin enable spectral unmixing of blood hemoglobin concentration and oxygenation in tissue. Moreover, MSOT is a relatively low cost imaging modality that can be combined with existing ultrasound systems and therefore holds significant potential as a future clinical tool.
We are working on the technical and biological validation of novel experimental and analytical methodologies for MSOT that provide new opportunities for evaluating cancer prognosis. This includes the use of light fluence models relevant for application in vivo as well as standardised protocols for contrast enhancement in tumour tissue. New fluorescent/optoacoustic contrast agents are also under development. We are ensuring biological validation of the available MSOT image features using preclinical models of breast and prostate cancer. We expect the use of MSOT to provide us with new insight into process of angiogenesis and mechanisms of response to novel anti-angiogenic therapies.
Michal Tomaszewski, Judith Weber, Dr James Joseph, Dr Isabel Quiros-Gonzalez, Dr Joanna Brunker.
Dr Oshaani Obeyakoon, Prof. Fiona Gilbert (Department of Radiology, University of Cambridge); Prof. Paul Beard (Department of Medical Physics and Bioengineering, UCL).