Custom-designed Verasonics-based multi-wavelength photoacoustic and ultrasound imaging: from technical advances to preclinical applications in cancer.

Real-time multi-wavelength photoacoustic (PA) imaging has emerged as a powerful modality for investigating tumor vascular dynamics, offering non-invasive, high-resolution visualization of hemodynamic changes that are critical for cancer diagnosis and therapeutic monitoring. In this study, we present a custom integration of the Verasonics Vantage ultrasound platform with an optical parametric oscillator (OPO) laser system. The first part of the study provides a comprehensive review of the current literature on PA imaging using the Verasonics system, emphasizing its capabilities, limitations, and adaptability for advanced imaging applications. Building upon this foundation, we introduce a robust framework that leverages the Verasonics system in conjunction with the fast-tuning capabilities of the OPO laser to enable synchronized, multi-wavelength PA imaging. In the second part of the study, we demonstrate selected applications of the developed system, such as multi-wavelength spectral imaging of tumor vasculature and near-real-time monitoring of therapeutic response. These case studies highlight the system's capability to capture dynamic physiological changes and support functional, longitudinal assessments in complex pathological environments. Future directions include the exploration of alternative tunable laser sources and the integration of machine learning algorithms to enhance real-time image reconstruction and spectral unmixing. Collectively, this work establishes a versatile and scalable platform for advancing PA imaging in preclinical and translational cancer research.