Photoacoustic clinical imaging

Abstract

Photoacoustic is an emerging biomedical imaging modality, which allows imaging optical absorbers in the tissue by acoustic detectors (light in - sound out). Such a technique has an immense potential for clinical translation since it allows high resolution, sufficient imaging depth, with diverse endogenous and exogenous contrast, and is free from ionizing radiation. In recent years, tremendous developments in both the instrumentation and imaging agents have been achieved. These opened avenues for clinical imaging of various sites allowed applications such as brain functional imaging, breast cancer screening, diagnosis of psoriasis and skin lesions, biopsy and surgery guidance, the guidance of tumor therapies at the reproductive and urological systems, as well as imaging tumor metastases at the sentinel lymph nodes. Here we survey the various clinical and pre-clinical literature and discuss the potential applications and hurdles that still need to be overcome.

Real-time spectroscopic photoacoustic/ultrasound (PAUS) scanning with simultaneous fluence compensation and motion correction for quantitative molecular imaging

“…Unlike previous delivery systems coupling laser pulses into all fibers in a bundle simultaneously [9], we couple light into individual fibers sequentially (see Figs We integrated all controls, including laser pulse activation/sequencing, motor scanning, and PAUS image acquisition, with a commercial scanner (Vantage, Verasonics, WA, USA). The motor encoder triggers the US system to launch interleaved US and PA pulse sequences and the US system externally triggers the laser, synchronizing all sub-systems ( Fig.…”

“…After compensation, every pixel carries information from all wavelengths without motion artifacts and, therefore, enables spectral decomposition of molecular constituents. 9 The images in Fig. 2c are in vivo data from a small animal.…”

“…For 25 years, PA imaging has been an active area and is now one of the hottest topics in biomedical optics. PA tomography (PAT) and microscopy (PAM) have numerous diagnostic applications [9][10][11], providing both endogenous [12][13][14][15] and exogenous molecular contrast in structural and functional images [15][16][17]. In particular, PA spectroscopy has produced functional images in the brain and heart [10,[18][19][20], and molecular images using the unique spectra of nanoengineered contrast agents [16,[20][21][22].…”

Short-wavelength optoacoustic spectroscopy based on water muting

“…However, the change in position should not pose a problem for quantitation of solutes in homogeneous solution. Nevertheless, accurate determination of the speed of sound may be useful, especially since it can allow an estimation of sample temperature [47] during solute quantification or spectral analysis, or in imaging applications [48]. CIROAS appears to be superior to alternative optical spectroscopic methods that use heavy water as the means to overcome the effects of strong water absorption [8].…”

An Up-To-Date Review on Biomedical Applications of Palladium Nanoparticles

“…The strong absorption in the NIR region of PdNPs maximizes the penetration of light into tissue [35]. Using the optical property of material, photoacoustic imaging (PAI) has been also recently developed as a novel promising imaging technique for early tumor diagnosis and management [36,37]. To enhance the photoacoustic signal from the tissue, photoacoustic agents are often required [38].…”