Calibration-free in vivo transverse blood flowmetry based on cross correlation of slow time profiles from photoacoustic microscopy
We propose a cross-correlation-based method to measure blood-flow velocity by using photoacoustic microscopy. Unlike in previous autocorrelation-based methods, the measured flow velocity here is independent of particle size. Thus an absolute flow velocity can be obtained without calibration. We first measured the flow velocity ex vivo, using defibrinated bovine blood. Then flow velocities in vessels with different structures in a mouse ear were quantified in vivo. We further measured the flow variation in the same vessel and at a vessel bifurcation. All the experimental results indicate that our method can be used to accurately quantify blood velocity in vivo.
Additional Information© 2013 Optical Society of America. Received July 30, 2013; accepted August 26, 2013; posted August 29, 2013 (Doc. ID 194945); published September 26, 2013. The authors thank Professor James Ballard for his close reading of the manuscript. This work was sponsored in part by the National Institutes of Health grants DP1 EB016986 (NIH Director's Pioneer Award), R01 EB008085, R01 CA134539, U54 CA136398, R01 EB010049, R01 CA157277, and R01 CA159959. L. W. has a financial interest in Microphotoacoustics, Inc. and Endra, Inc., which, however, did not support this work. K. M. has a financial interest in Microphotoacoustics, Inc., which, however, did not support this work.
Published - ol-38-19-3882.pdf