Acoustic attenuation compensation in photoacoustic tomography: Application to high-resolution 3D imaging of vascular networks in mice

Abstract

The reconstruction algorithms commonly used in photoacoustic tomography do not account for the effects of acoustic attenuation on the measured time-domain signals. For experimental measurements made in biological tissue, acoustic attenuation causes the high frequency components of the generated ultrasound signals to be significantly reduced. When this signal loss is neglected, it manifests as a depth dependent magnitude error and blurring of features within the reconstructed photoacoustic image. Here, the approach described by Treeby et al. [Inverse Problems 26(11), p. 115003, 2010] is applied to the reconstruction of high-resolution three-dimensional photoacoustic images of vascular networks around the abdomen of a pregnant female mouse. The reconstruction is based on the idea of time reversal in which a numerical model of the acoustic forward problem is run backwards in time. Compensation of acoustic attenuation in the inverse problem is achieved by using a forward model that accurately accounts for the frequency dependent attenuation experimentally observed in biological tissue. The regularisation of the inverse problem is discussed, and the methodology demonstrated through the reconstruction of several images. Clear improvements in image magnitude and resolution are seen when attenuation compensation is included.