Photoacoustic imaging on its way toward clinical utility: a tutorial review focusing on practical application in medicine

Abstract

Photoacoustic imaging (PAI) enables the visualization of optical contrast with ultrasonic imaging. It is a field of intense research, with great promise for clinical application. Understanding the principles of PAI is important for engineering research and image interpretation.Aim: In this tutorial review, we lay out the imaging physics, instrumentation requirements, standardization, and some practical examples for (junior) researchers, who have an interest in developing PAI systems and applications for clinical translation or applying PAI in clinical research.Approach: We discuss PAI principles and implementation in a shared context, emphasizing technical solutions that are amenable to broad clinical deployment, considering factors such as robustness, mobility, and cost in addition to image quality and quantification.Results: Photoacoustics, capitalizing on endogenous contrast or administered contrast agents that are approved for human use, yields highly informative images in clinical settings, which can support diagnosis and interventions in the future.Conclusion: PAI offers unique image contrast that has been demonstrated in a broad set of clinical scenarios. The transition of PAI from a "nice-to-have" to a "need-to-have" modality will require dedicated clinical studies that evaluate therapeutic decision-making based on PAI and consideration of the actual value for patients and clinicians, compared with the associated cost.

Mapping cutaneous field carcinogenesis of nonmelanoma skin cancer using mesoscopic imaging of pro‐inflammation cues

“…Photoacoustic imaging is another emerging biomedical imaging modality that combines the strengths of both ultrasound and optical imaging 67–69 . Short laser pulses are delivered to tissues, leading to the generation of acoustic waves through the photoacoustic effect—the absorption of light energy by tissues results in thermoelastic expansion and the subsequent emission of ultrasound waves.…”

“…Photoacoustic imaging is another emerging biomedical imaging modality that combines the strengths of both ultrasound and optical imaging. [67][68][69] Short laser pulses are delivered to tissues, leading to the generation of acoustic waves through the photoacoustic effect-the absorption of light energy by tissues results in thermoelastic expansion and the subsequent emission of ultrasound waves. These ultrasound signals are then detected and used to construct high-resolution images that reveal the distribution of light-absorbing molecules, such as haemoglobin, within biological tissue.…”

Pre-transplant kidney quality evaluation using photoacoustic imaging during normothermic machine perfusion

“…Unlike optical imaging modalities, PA can image up to a depth of a few centimeters, making it suitable for imaging renal cortex. The unique absorption spectrum of each chromophore enables its quantification within the sample [25] , [26] .…”

Mini review of photoacoustic clinical imaging: a noninvasive tool for disease diagnosis and treatment evaluation

“… 1 , 3 , 4 The transformation of PA effects from a theoretical concept to a valuable imaging modality has taken over a century of development. 5 , 6 In recent years, numerous research groups and companies have developed medical devices and processing systems available for human imaging. 1 , 2 , 6 – 8 Typically, PA imaging devices consist of several essential components, including a short-pulsed laser for generating PA signals, an ultrasonic transducer or transducer array for detecting PA signals, a data-acquisition system for amplifying and digitizing PA signals, and a computer for forming image.…”

“… 1 , 2 , 6 – 8 Typically, PA imaging devices consist of several essential components, including a short-pulsed laser for generating PA signals, an ultrasonic transducer or transducer array for detecting PA signals, a data-acquisition system for amplifying and digitizing PA signals, and a computer for forming image. 1 , 6 …”