Photoacoustic microscopy using Evans Blue dye as a contrast agent
Complete and continuous imaging of microvascular networks is crucial for a wide variety of biomedical applications. Photoacoustic tomography can provide high resolution microvascular imaging using hemoglobin within red blood cells (RBC) as an endogenous contrast agent. However, intermittent RBC flow in capillaries results in discontinuous and fragmentary capillary images. To overcome this problem, we used Evans Blue (EB) dye as a contrast agent for in vivo photoacoustic imaging. EB has strong optical absorption at 610 nm and distributes uniformly in the blood stream by chemically binding to albumin. By intravenous injection of EB (6%, 200 μL), complete and continuous microvascular networks-especially capillaries-of the ears of nude mice were imaged. The diffusion of EB (3%, 100 μL) leaving the blood stream was monitored for 2 hours. At lower administration dose of EB (3%, 50 μL), the clearance of the EB-albumin complex was imaged for 10 days and quantitatively investigated using a two-compartment model.
Additional Information© 2010 Society of Photo-Optical Instrumentation Engineers (SPIE). This research is supported by the National Institutes of Health Grants R01 EB000712, R01 NS46214, R01 EB008085 and U54 CA136398. Lihong V. Wang has a financial interest in Endra, Inc., which, however, did not support this work.
Published - 75642J.pdf