Figure 3.
Major hardware configurations for PAI. (A) OR-PAM of oxygen saturation in a mouse ear. The light source is focused by an objective lens and sound is focused by a concave lens at the bottom of the prism where it is reflected to the ultrasound transducer (UST). (B) AR-PAM of hemoglobin concentration in a human palm. Dark-field illumination creates a cone of light rather than a point. (C) Linear Array PACT of methylene blue localized to a rat sentinel lymph node. Diffuse homogenous light illuminates the sample and is collected by a scanning line of transducer elements. (D) Circular Array PACT of cerebral [hemoglobin] dynamics. The array of ultrasound transducers can detect acoustic waves generated by the sample in all directions of a given plane. (E) PAE of a rabbit esophagus where components have been miniaturized for internal imaging. Adapted with permission from 3, copyright 2012 AAAS.