Sound Out the Deep Clarity: Super-Resolution Photoacoustic Imaging at Depths.

Photoacoustic imaging (PAI), also known as optoacoustic imaging, is a hybrid imaging modality that combines the rich contrast of optical imaging with the deep penetration of ultrasound (US) imaging. Over the past decade, PAI has been increasingly utilized in biomedical studies, providing high-resolution high-contrast images of endogenous and exogenous chromophores in various fundamental and clinical research. However, PAI faces challenges in achieving high imaging resolution and deep tissue penetration simultaneously, limited by the optical and acoustic interactions with tissues. Overcoming these limitations is crucial for maximizing the potential of PAI for biomedical applications. Recent advances in super-resolution (SR) PAI have opened new possibilities for achieving high imaging resolution at greater depths. This review provides a comprehensive summary of these promising strategies, highlights their representative applications, envisions the potential future directions, and discusses the broader impact on biomedical imaging.