Comparison of the Quality of Lymphatic Vessel Images Obtained Using Two Photoacoustic Imaging Systems

Photoacoustic imaging (PAI) can evaluate lymphatic vessels with a high resolution (0.2 mm) compared with other methods. LUB0, a new PAI device that is smaller than the PAI-05 used since 2020 (both from Luxonus, Inc.), has been introduced. We aimed to determine the imaging capability of LUB0 by comparing it with that of PAI-05. Two healthy individuals and 4 patients with lymphedema underwent PAI using PAI-05 and LUB0. Each participant was subcutaneously injected with indocyanine green to visualize the lymphatic vessels. PAI was performed after confirming that the lymphatic flow had moved to the central part of the body using a near-infrared camera. Four physicians selected a device with superior image clarity based on a 5-point scale. LUB0 produced sharper images of lymphatic vessels and veins than PAI-05. The physicians scored 3.0 ± 1.2 with PAI-05 and 3.9 ± 0.9 with LUB0 (P < 0.05), implying that LUB0 provided significantly clearer images. Additionally, the dermal backflow image obtained using LUB0 from a patient with lymphedema depicted the precollector lymphatic vessels more clearly. LUB0 occupies approximately one-seventh of the footprint of PAI-05 and requires a shorter imaging time (5 minutes) than PAI-05 (10 minutes). The PAI model LUB0 improved the visualization of lymphatic vessels and veins, allowing better detection and evaluation of lymphatic vessels.