Noninvasive photoacoustic synergistic measurement of vascular morphology and blood flow velocity

Photoacoustic imaging is a multimodal imaging technique combining optical and acoustic principles to observe and analyze structural and functional tissue information. This study presents a photoacoustic velocimetry and imaging experimental system for synergistic measurement of vascular morphology and blood flow velocity. The system, equipped with a 532 nm pulsed laser and optical-acoustic combiner, achieves a horizontal resolution of 10 μm. It measures flow velocities ranging from 25 to 200 mm/s with an average error of 8.2%. Through two-dimensional scanning and Gaussian filtering, the vascular morphology was reconstructed with a Dice Similarity Coefficient of 0.92. Compared to conventional imaging systems, the proposed system enhances small vessel resolution by up to 40% and achieves a signal-to-noise ratio improvement of 7 dB. These results highlight the system's potential for precise and noninvasive biomedical applications, including real-time diagnosis and monitoring. Vascular imaging plays a critical role in biomedical research, aiding in understanding vascular structure and function and exploring cardiovascular diseases, tumor angiogenesis, hemodynamics, and other related diseases. Noninvasive imaging techniques can evaluate disease progression and therapy efficacy. Accurate blood flow measurement is essential for diagnosing various diseases, including stroke, diabetes, and cancer. This work demonstrates a synergistic photoacoustic system capable of achieving high-resolution vascular imaging and flow velocity measurements.