Progress of clinical translation of handheld and semi-handheld photoacoustic imaging

Abstract

Photoacoustic imaging (PAI), featuring rich contrast, high spatial/temporal resolution and deep penetration, is one of the fastest-growing biomedical imaging technology over the last decade. To date, numbers of handheld and semi-handheld photoacoustic imaging devices have been reported with corresponding potential clinical applications. Here, we summarize emerged handheld and semi-handheld systems in terms of photoacoustic computed tomography (PACT), optoacoustic mesoscopy (OAMes), and photoacoustic microscopy (PAM). We will discuss each modality in three aspects: laser delivery, scanning protocol, and acoustic detection. Besides new technical developments, we also review the associated clinical studies, and the advantages/disadvantages of these new techniques. In the end, we propose the challenges and perspectives of miniaturized PAI in the future.

3D Ultrasound-Guided Photoacoustic Imaging to Monitor the Effects of Suboptimal Tyrosine Kinase Inhibitor Therapy in Pancreatic Tumors

“…We believe that these changes may become even more pronounced through intravenous delivery of the therapies, as oral delivery may not produce as drastic volumetric reductions as anticipated and seen in previous studies (76). Furthermore, recent developments in clinical translation of PAI (77)(78)(79) including portable real-time LED-based PAI systems for cancer applications (80) and endoscopic PAI systems (81)(82)(83) show promise toward employing photoacoustic monitoring of tumor response to treatment not only for pancreatic tumors but also for other solid tumors undergoing neoadjuvant treatment. Overall, given the exponential rise in the technical advances and biological applications of PAI over the past decade, the results presented in this study further support its utility as a useful tool to monitor cancer treatment response, especially in imaging response of suboptimal therapies.…”

Randomized multi‐angle illumination for improved linear array photoacoustic computed tomography in brain

“…Photoacoustic (PA) tomography is an imaging modality based on photoacoustic technique, where acoustic wave in ultrasound range is induced from transient thermo-elastic expansion of biological tissue chromophores due to absorption of light [1][2][3]. Among PA imaging techniques, photoacoustic computed tomography (PACT) using a handheld linear array ultrasound transducer is the most popular configuration in a clinical setup [4][5][6]. With this configuration, typically the delivery of the optical energy is realized through circular or rectangular optical fiber output; attached to both side of the elevation plane of the transducer.…”

High-speed photoacoustic microscopy: A review dedicated on light sources

“…The PACT typically uses multi-element US transducers with various geometries such as linear [ [17] , [18] , [19] ], arc [ [20] , [21] , [22] ], hemisphere [ [23] , [24] , [25] ], or planar [ 26 ] array to obtain tomographic or cross-sectional images. The PACT systems take advantages of real-time imaging capability (typically 5–20 Hz) and deep imaging depth (up to ∼5 cm) and have been used for several clinical applications [ [27] , [28] , [29] , [30] , [31] , [32] , [33] ], such as breast [ [34] , [35] , [36] ], prostate [ [37] , [38] , [39] ], thyroid [ 40 , 41 ], and melanoma [ 42 , 43 ]. In addition to the human clinical applications, PACT systems also have been applied to small animal studies, including brain imaging [ 44 ], whole-body dynamics monitoring [ 45 ], and deep-tissue imaging [ 46 ].…”