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In an animal model, IVPAT allowed characterization of spatial and quantitative features of lipid-rich plaques.

We have developed an intravascular confocal photoacoustic (PA) endoscope with symmetrically aligned dual-element ultrasonic transducers. By combining focused laser excitation and focused acoustic collection, the intravascular confocal PA endoscope is capable of realizing resolution enhanced intravascular PA imaging with improved signal-to-noise ratio (SNR) to ameliorate the resolution reduction caused by laser scattering with increasing tissue depth. The detection sensitivity of the endoscope is improved by 5 dB compared with that of single transducer endoscope, and the transverse resolution of the system can up to 13 μm. Intravascular PA tomography of a normal vessel and an atherosclerotic vessel have been performed to demonstrate the imaging ability of the system. This intravascular confocal PA endoscope with an outer diameter of 1.2 mm supports potential for clinical applications in intravascular plaque imaging and subsequent diagnosis.

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We present a 3D-visual laser-diode-based photoacoustic imaging (LD-PAI) system with a pulsed semiconductor laser source, which has the properties of being inexpensive, portable, and durable. The laser source was operated at a wavelength of 905 nm with a repetition rate of 0.8 KHz. The energy density on the sample surface is about 2.35 mJ/cm(2) with a pulse energy as low as 5.6 μJ. By raster-scanning, preliminary 3D volumetric renderings of the knotted and helical blood vessel phantoms have been visualized integrally with an axial resolution of 1.1 mm and a lateral resolution of 0.5 mm, and typical 2D photoacoustic image slices with different thickness and orientation were produced with clarity for detailed comparison and analysis in 3D diagnostic visualization. In addition, the pulsed laser source was integrated with the optical lens group and the 3D adjustable rotational stage, with the result that the compact volume of the total radiation source is only 10 × 3 × 3 cm(3). Our goal is to significantly reduce the costs and sizes of the deep 3D-visual PAI system for future producibility.

BaTiO3 (BTO) ceramics were fabricated based on stereolithography technology. The microstructures and electric properties of the BTO ceramics were studied. X-ray patterns of sintered BTO ceramics indicated that the tetragonal phase had formed, and the grain size increased clearly as BTO weight percentage increased. Moreover, the BTO ceramics exhibited good electric properties, with a piezoelectric constant d33 of 166 pC/N at 80% BTO weight percentage. To evaluate the properties of 3D printed BTO ceramics, a 1.4 MHz focused ultrasonic array was fabricated and characterized. The −6dB bandwidth of the array was 40%, and the insertion loss at the center frequency was 50 dB. The results show that the printed BTO ceramics array have good potential to be used in ultrasonic transducers for various applications.

Optical-resolution photoacoustic microscopy (OR-PAM) has been significantly improved in terms of spatial resolution, detection sensitivity, imaging speed, and penetration depth. However, the popular producibility of OR-PAM system is still limited by the size and cost of solid-state laser excitation. Here, we developed a portable laser-diode-based OR-PAM (LD-OR-PAM) system using a pulsed semiconductor laser source, which was operated at 905 ± 15 nm with a pulse energy as low as 4.9 μJ. The measured lateral resolution has been improved to ∼1.5 μm from hundreds of microns. The compact and inexpensive natures of LD-OR-PAM would promote the potential clinical applications such as in dermatology.