in: Emerging Trends in Ultrasound Imaging, Dave Fornell, Editor, OpenAccess e Books, Nevada, pp.1-8, 2020
Ultrasound has proved its diagnostic value through last five decades. For the observation of soft tissue, ultrasound (US) imaging has become very popular, since it has high axial and lateral resolutions of approximately 20-100 μm and a good penetration depth of approximately 5 mm. US imaging has also low cost, however, it can only provide information about the morphology. Scanning acoustic microscopy (SAM) is an imaging tool which uses high frequency ultrasound and provides morphological and mechanical information about the specimen simultaneously at microscopic levels. Photoacoustic microscopy (PAM) is a well- known imaging modality that combines optical and ultrasound imaging and obtains chemical and morphology information with a good penetration depth and with a micrometer resolution. Detection of micro-meter sized formations within tissues or cells with a good penetration depth is possible with a combined SAM and PAM system, which uses ultrasound waves rather than a system using ionizing radiation.