Basics and Clinical Applications of Photoacoustic Imaging

Photoacoustic Imaging in Oncology: Translational Preclinical and Early Clinical Experience

“…These systems are mainly geared toward research and often provide custom image processing software that allows users to perform a multitude of tasks ranging from importing raw data for offline processing, to onboard three-dimensional image reconstruction, and real-time image display. Currently, there are two commercially available preclinical photoacoustic imaging systems as shown in Figure 3: Vevo LAZR (Fujifilm VisualSonics, Toronto, Canada; technology licensed from Seno Medical Instruments, San Antonio, Tex) and Nexus 128 (Endra, Ann Arbor, Mich; technology licensed from OptoSonics, Oriental, NC) (7,(44)(45)(46)(47)(48)(49). Vevo LAZR uses high-frequency where tissue with lower oxygen saturation is considered more likely to be cancerous due to cancer's known hypoxic nature in later stages (27,28).…”

Fabrication of a novel C-scan photoacoustic imaging camera

“…A valuable feature of PAI is the ability to discriminate among tissue constituents on the basis of optical absorption properties, allowing for PAI spectroscopy, which can detect biological function [1,2]. PAI can map the concentration of deoxy-hemoglobin and oxy-hemoglobin, as well as water and lipid in the tissue [1,2] . Research based evidence pointing towards its usefulness in cancer diagnosis and disease management is growing day by day [1,2].…”

“…A linear array of N ultrasound transducer receiving elements is located in the image plane at a distance 2f to the right of the lens. When the tissue is exposed to a short pulse of NIR laser, point absorbers expand and relax, generating a short pulse of US waves via PA effect [1,2] . These US waves propagating towards the lens are brought to focus at the image plane where the resulting sensor electrical signal is recorded at N pixel locations simultaneously.…”

“…PAI can map the concentration of deoxy-hemoglobin and oxy-hemoglobin, as well as water and lipid in the tissue [1,2] . Research based evidence pointing towards its usefulness in cancer diagnosis and disease management is growing day by day [1,2]. Many believe that PAI is poised to become the next major clinical imaging modality within a decade.…”

“…It employs short laser light pulses in the near-infra-red (NIR) to excite molecules in the tissue, producing localized thermal expansion that generates ultrasonic waves [1]. A valuable feature of PAI is the ability to discriminate among tissue constituents on the basis of optical absorption properties, allowing for PAI spectroscopy, which can detect biological function [1,2]. PAI can map the concentration of deoxy-hemoglobin and oxy-hemoglobin, as well as water and lipid in the tissue [1,2] .…”