Cost-effective imaging of optoacoustic pressure, ultrasonic scattering, and optical diffuse reflectance with improved resolution and speed.

The idea of a method of cost-effective upgrades from an acoustic resolution photoacoustic microscope to a triple-modality imaging system is validated using phantoms. The newly developed experimental setup is based on a diode pumped solid state laser coupled to a fiber bundle with a spherically focused polyvinylidene fluoride detector integrated into the center of a ring shaped optical illuminator. Each laser pulse illuminating the sample performs two functions. While the photons absorbed by the sample provide a measurable optoacoustic (OA) signal, the photons absorbed by the detector provide the measurable diffuse reflectometry (DR) signal from the sample and the probing ultrasonic (US) pulse. At a 3 mm imaging depth, the axial resolution of the OA/US modalities is 38 μm/26 μm, while the lateral resolution of the DR/OA/US modalities is 3.5 mm/50 μm/35 μm. The maximum acquisition rate of the trimodal DR/OA/US A-scans is 2 kHz.