Fig. 1
From: Functional photoacoustic imaging: from nano- and micro- to macro-scale
Characteristics of PAI, from surface to cm depth. a PAI depths, from the surface to one cm deep, with corresponding lateral resolutions. b Configuration of PAI for different scales. At nanoscale, microscale, and macroscale, the lateral resolutions are approximated by the sizes of the tip, optical focus, and acoustic focus, respectively. c Representitve super-resolution to deep-tissue functional PA images. Panels 1–9 respectively show an organic semiconductor crack, mitochondria, microvasculature with melanoma, brain vasculature and SO2 change, a blood vessel SO2 map with melanoma, human melanoma vasculature, the hemodynamics of a fatty liver, the hemodynamics of cerebral, and whole body vasculature, PAI, photoacoustic imaging; PA, photoacoustic; SO2, oxygen saturation; TR, ultrasound transducer; BC, beam combiner; Obj, objective lens. The images are reproduced with permission from [17, 24, 25, 82,83,84,85,86,87]