Five-wavelength optical-resolution photoacoustic microscopy of blood and lymphatic vessels

Abstract

In vivo imaging of blood vessels and lymphatic vessels is important for monitoring physiological parameters and early diagnosing of fatal diseases.^{1 – 3} The blood and lymphatic vessels are two sets of circulatory networks that have distinct but interdependent functions. Lymphatic vessels are found in most tissues and play an important role in many physiological processes.⁴ The blood circulation supplies oxygen and nutrients, removes waste, and is highly associated with the lymphatic circulation. Recent research has shown that blood flow, local oxygen content, and lymphatic vessels are important factors in tumor growth and metastasis.^{5 – 14} Simultaneous imaging of blood and lymphatic vessels is of great value in disease diagnosis and treatment.³ Most existing bioimaging techniques are limited to either low spatial/temporal resolution or unable to simultaneously image multi-contrasts in the blood and lymphatic vessels. A high-resolution multi-contrast imaging technique that can image both the blood and the lymphatic vessels is highly needed.