A piezoelectric detection system consisting of an annular array is investigated for large depth of field photoacoustic imaging. In comparison to a single ring detection system, X-shaped imaging artifacts are suppressed. Sensitivity and image resolution studies are performed in simulations and in experiments and compared to a simulated spherical detector. In experiment an eight ring detection sy...

EGFR is a promising cell surface target for in vivo imaging that is highly overexpressed in hepatocellular carcinoma (HCC), a common cancer worldwide. Peptides penetrate easily into tumors for deep imaging, and clear rapidly from the circulation to minimize background. We aim to demonstrate use of an EGFR specific peptide to detect HCC xenograft tumors in mice with photoacoustic imaging. Nude m...

We introduce a method to extract the photoacoustic (PA) signal from the phase time evolution of an optical coherence tomography (OCT) swept source spectral sweep. This all-optical detection is achieved in a noncontact fashion directly on the sample surface by using its specular reflection. High-speed measurement and referencing allow for close to shot noise limited phase-sensitive detection. It...

We report the development of photoacoustic flowmetry assisted by high-intensity focused ultrasound (HIFU). This novel method employs HIFU to generate a heating impulse in the flow medium, followed by photoacoustic monitoring of the thermal decay process. Photoacoustic flowmetry in a continuous medium remains a challenge in the optical diffusive regime. Here, both the HIFU heating and photoacous...

The photoacoustic effect produced by laser-induced stress waves in liquids has found a variety of scientific and practical applications in industry, medicine and environmental protection. The photoacoustic effect has the natural advantage of being less sensitive to scattering than traditional optical tools, thus offering increased accuracy and sensitivity. This paper aims to give a systematic o...

Photoacoustic imaging (PAI) is an emerging noninvasive and inexpensive bioimaging modality, which has stimulated a wide interest in recent years for cancer theranostics. Hybrid nano- microgels have been designed as protective carriers to incorporate PAI contrast agents due their biocompatibility biodegradability, high loading capacity, versatile surface chemistry, stimuli-responsive properties....

The thermo physical parameters thermal effusivity (e) and thermal diffusivity (α) have been measured using Fourier transform infrared (FTIR) Photoacoustic spectroscopy (PAS) for two different purities of C60 fullerenes (99.5 % , 98.5%) samples in the powder form. The experimental results shows that the values of thermal diffusivity is less then that obtained for crystalline C60 fullerenes. The ...

There exist various reconstruction formulas and back-projection algorithms for photoacoustic imaging (see the survey [4] and the references therein). Also different measurement devices for the ultrasound pressure have been suggested. Most common are small detectors based on materials, which exhibit a strong piezoelectric effect and can be immersed safely in water (i.e. polymers such as PVDF). I...

Photoacoustic imaging using a closed photoacoustic cell and an open photoacoustic cell with gasmicrophone detection scheme was described. R/G/B LED light sources were used for the closed photoacoustic (PA) cell configuration. The colored specimen enclosed in a PA cell was imaged with R/G/B color light sources, and an image restored from the inverted PA images was compared with the original imag...

A photoacoustic (PA) imaging that utilizes acoustic detection of sound generated by a specimen due to the absorption of modulated light was applied to measure the amount of the pollen of the Cryptomeria japonica, Asian allergic plant. High-sensitivity PA imaging can measure pollen particles with a large dynamic range from single particle to several hundred micrograms. The PA signal dependence o...