Deep Tissue Imaging: Acoustic and Thermal Wave Propagation and Light Interactions in Tissue
This chapter describes a set of tools for functional and structural imaging with localized treatment under feedback. Photothermal, photoacoustic, radiotherapy under thermal imaging for real time assessment of treatment are described and discussed. The chapter presents the works which consist of photoacoustic imaging to quantify blood flow rate through the Doppler effect and the thermal diffusion effect. Photoacoustic (PA) imaging is a relatively new, non-ionizing, biomedical imaging modality, based on light-generated ultrasound. Although the PA effect was first discovered by Alexander Graham Bell in the 19th century. Despite the similarities in detection methods, ultrasound (US) and PA imaging are based on different contrast sources. Acousto-optic modulation of coherent, near-infrared light signals within scattering biological tissue enables to better localize the optical path of photons within the tissue and thus reduce the effect of superficial contamination.