  Optoacoustic image formation is conventionally based upon ultrasound
time-of-flight readings from multiple detection positions. Herein, we exploit
acoustic scattering to physically encode the position of optical absorbers in
the acquired signals, thus reduce the amount of data required to reconstruct an
image from a single waveform. This concept is experimentally tested by
including a random distribution of scatterers between the sample and an
ultrasound detector array. Ultrasound transmission through a randomized
scattering medium was calibrated by raster scanning a light-absorbing
microparticle across a Cartesian grid. Image reconstruction from a single
time-resolved signal was then enabled with a regularized model-based iterative
algorithm relying on the calibration signals. The signal compression efficiency
is facilitated by the relatively short acquisition time window needed to
capture the entire scattered wavefield. The demonstrated feasibility to form an
image using a single recorded optoacoustic waveform paves a way to the
development of faster and affordable optoacoustic imaging systems.
