—
Medical professionals have long sought after a non-invasive imaging technique that can provide deep insight into the condition and function of blood vessels within the human body. A breakthrough in this quest has been made with the development of a revolutionary technique known as photoacoustic vector tomography (PAVT).
Blood flow plays a pivotal role in numerous health conditions, such as heart attacks, diabetes, tumors, and brain function. However, examining blood vessels located deep within the body has traditionally required invasive procedures. Optical imaging techniques have been limited to imaging within approximately 1mm below the skin’s surface, hindering our ability to fully assess the haemodynamics of deeper vessels.
Recent research, detailed in a report by Nature Biomedical Engineering, has showcased the potential of PAVT to break through this optical diffusion limit. By leveraging the spatial heterogeneity of blood and its photoacoustic contrast, successive single-shot wide-field photoacoustic images of blood vessels can visualize the frame-to-frame propagation of blood and estimate blood flow speed and direction pixel-wise. This innovative imaging method has been shown to allow for the quantification of haemodynamics in veins more than 5mm deep, as demonstrated in regions in the hands and arms of healthy volunteers.
Moreover, another groundbreaking study detailed in the same report has introduced a technique for ultrafast volumetric photoacoustic imaging of haemodynamics in the human body at up to 1kHz using a single laser pulse and a single element functioning as 6,400 virtual detectors. This method enables the longitudinal volumetric imaging of haemodynamics in vasculature a few millimetres below the skin’s surface and may facilitate the early detection and monitoring of peripheral vascular diseases.
These breakthroughs have the potential to revolutionize the diagnosis and monitoring of vascular diseases, as well as the mapping of the function of the circulatory system. Notably, the non-invasive nature of these imaging techniques eliminates the need for ionizing radiation or contrast agents and overcomes the limitations of current imaging depth, data-acquisition systems, imaging speeds, and system complexity. The implications of these advancements have far-reaching possibilities, from enabling early detection and monitoring of diseases to facilitating biometrics and point-of-care testing.
The introduction of PAVT and ultrafast volumetric photoacoustic imaging represents a paradigm shift in how medical professionals can assess blood vessel conditions and haemodynamics within the human body. These cutting-edge techniques have the potential to significantly improve the diagnostic capabilities and overall understanding of vascular health, paving the way for more effective treatments and interventions in the future.
