Vascular Phenotyping with Photoacoustic and Ultrasound Imaging in Cardiovascular Disease: Recent Innovations.

Purpose of Review: Photoacoustic and ultrasound imaging together resolve vascular structure, wall biomechanics, blood flow, oxygenation, and tissue composition without ionizing radiation or iodinated contrast. This review summarizes what each modality can now measure in patients and asks which of these measurements are close enough to clinical use to inform cardiovascular management decisions. Recent Findings: Recent advances have expanded photoacoustic imaging toward faster, higher-resolution functional vascular phenotyping, including clinically relevant biomarkers and co-registered ultrasound imaging. Ultrafast and super-resolution ultrasound now quantify vascular biomechanics, hemodynamics, and microvasculature, with ultrasound localization microscopy entering clinical studies. Wearable ultrasound has also been validated for blood-pressure monitoring across diverse care settings, alongside increasingly quantitative feature extraction. Summary: Ultrasound and photoacoustic imaging provide complementary vascular information: ultrasound offers depth, speed, and continuous access, while photoacoustic imaging adds compositional and oxygenation contrast. Despite limitations in quantitative accuracy, imaging depth, and system standardization, emerging patient studies now span super-resolution vascular mapping, functional biomarkers, and wearable monitoring. Their integration offers a potential route toward continuous, operator-independent vascular phenotyping for clinical decision-making.