Calibration-free absolute quantification of optical absorption coefficients using acoustic spectra in 3D photoacoustic microscopy of biological tissue.
Optical absorption is closely associated with many physiological important parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of nonfluorescent molecules. We propose a method to use acoustic spectra of photoacoustic signals to quantify the absolute optical absorption. This method is self-calibrating and thus insensitive to variations in the optical fluence. Factors such as system bandwidth and acoustic attenuation can affect the quantification but can be canceled by dividing the acoustic spectra measured at two optical wavelengths. Using optical-resolution photoacoustic microscopy, we quantified the absolute optical absorption of black ink samples with various concentrations. We also quantified both the concentration and oxygen saturation of hemoglobin in a live mouse in absolute units.
Guo
Zijian
Z
Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University, 1 Brookings Drive, Saint Louis, Missouri 63130, USA.
Hu
Song
S
Wang
Lihong V
LV
D000042:Absorption; D000162:Acoustics / Q000295:instrumentation*; D000818:Animals; D001784:Blood Gas Analysis; D002138:Calibration; D004423:Ear / Q000098:blood supply; D005240:Feasibility Studies; D006454:Hemoglobins / Q000032:analysis; D051379:Mice; D008819:Mice, Nude; D008853:Microscopy; D010092:Oximetry / Q000379:methods
D006454:Hemoglobins