Simultaneous in vivo imaging of diffuse optical reflectance, optoacoustic pressure and ultrasonic scattering.

ABSTRACT

We present reflection-mode bioimaging system providing complementary optical, photoacsoutic and acoustic measurements by acoustic detector after each laser pulse. While the photons absorbed within the sample provide optoacoustic (OA) signals, the photons absorbed by the external electrode of a detector provide the measurable diffuse reflectance (DR) from the sample and the probing ultrasonic (US) pulse. To demonstrate the in vivo capabilities of the system we present the results of complementary DR/OA/US imaging of a mouse tumor, head of a newborn rat, and the back of a newborn rat with 3.5mm/50µm/35µm lateral resolution. Trimodal approach allows visualization of mechanical structures in healthy and pathological tissues along with peculiarities of blood supply. The system may be used for diagnostics of diseases accompanied by the defects of vascularization as well as for assessing the mechanisms of vascular changes when monitoring response to therapy.