Application of high-resolution ultrasound/photoacoustic imaging for medicine and biology

Abstract Because the frequency is inversely proportional to the wavelength or beamwidth of the ultrasound, very high-resolution imaging is available by high frequency ultrasound. The application of ultrasound microscopy in medicine and biology has three main purposes. The first is rapid diagnosis, the second is to collect the basic acoustic properties necessary to understand clinical ultrasound imaging and the third is to gather information about the biomechanics of the tissue. In photoacoustic imaging, very short pulsed light emitted to the material evoked thermal expansion to generate photoacoustic signal. A number of photoacoustic systems have been devised and put into practical use to efficiently irradiate light and receive photoacoustic signal. Those systems can be broadly classified into acoustical resolution photoacoustic microscopy (AR-PAM), optical resolution photoacoustic microscopy, optical resolution photoacoustic microscopy (AR-PAM) and optical acoustic microscopy (PAM). There is a need for more compact systems with stable prices for clinical applications.