© 2015 SPIE. We propose a new reconstruction algorithm for photoacoustic and laser-ultrasound imaging based on reversetime migration (RTM), a time reversal imaging algorithm originally developed for exploration seismology. RTM inherently handles strong velocity heterogeneity and complex propagation paths. A successful RTM analysis with appropriate handling of boundary conditions results in enhanced signal-to-noise, accurately located structures, and minimal artifacts. A laser-ultrasound experiment begins with a source wavefield generated at the surface that propagates through the sample. Acoustic scatterers in the propagation path give rise to a scattered wavefield, which travels to the surface and is recorded by acoustic detectors. To reconstruct the laser-ultrasound image, a synthetic source function is forward propagated and cross-correlated with the time-reversed and back-propagated recorded (scattered) wavefield to image the scatterers at the correct location. Conversely, photoacoustic waves are generated by chromophores within the sample and propagate "one-way" to the detection surface. We utilize the velocity model validated by the laser-ultrasound reconstruction to accurately reconstruct the photoacoustic image with RTM. This approach is first validated with simulations, where inclusions behave both as a photoacoustic source and an acoustic scatterer. Subsequently, we demonstrate the capabilities of RTM with tissue phantom experiments using an all-optical, multi-channel acquisition geometry.
|Title of host publication||Proceedings Volume 9323, Photons Plus Ultrasound: Imaging and Sensing 2015|
|Place of Publication||Washington, USA|
|Publication status||Published - 2015|
|Event||SPIE BiOS 2015 - San Francsisco, United States|
Duration: 7 Feb 2015 → 12 Feb 2015
|Conference||SPIE BiOS 2015|
|Period||7/02/15 → 12/02/15|