Self-fluence-compensated functional photoacoustic microscopy

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)3856-3866
Journal / PublicationIEEE Transactions on Medical Imaging
Volume40
Issue number12
Online published26 Jul 2021
Publication statusPublished - Dec 2021

Abstract

Optical-resolution photoacoustic microscopy (OR-PAM) can image blood oxygen saturation (sO2) in vivo with high resolution and excellent sensitivity and offers a great tool for neurovascular study and early cancer diagnosis. OR-PAM ignores the wavelength-dependent optical attenuation in superficial tissue, which cause errors in sO2 imaging. Monte Carlo simulation shows that variations in imaging depth, vessel diameter, and focal position can cause up to ~60% decrease in sO2 imaging. Here, we develop a self-fluence-compensated OR-PAM to compensate for the wavelength-dependent fluence attenuation. We propose a linearized model to estimate the fluence attenuations and use three optical wavelengths to compensate for them in sO2 calculation. We validate the model in both numerical and physical phantoms and show that the compensation method can effectively reduce the sO2 errors. In functional brain imaging, we demonstrate that the compensation method can effectively improve sO2 accuracy, especially in small vessels. Compared with uncompensated ones, the sO2 values are improved by 10~30% in the brain. We monitor ischemic-stroke-induced brain injury which demonstrates great potential for the preclinical study of vascular diseases.

Research Area(s)

  • Absorption, Adaptive optics, Biomedical optical imaging, ischemic stroke, Monte Carlo simulation, Optical attenuators, Optical imaging, Optical saturation, Optical scattering, oxygen saturation, Photoacoustic microscopy