Table 2.
Summary of the microscale photoacoustic imaging system specifications
| Ref. | System scale | Functionality and application | Transducer | Laser | Lateral resolution | Imaging depth | ||
|---|---|---|---|---|---|---|---|---|
| f (MHz) | Element | PRF | Wavelength (nm) | |||||
| [82] | SW-PAM | Single cells, blood vessels and melanoma | 40 | 1 | – | 532 | 220 nm | a hundred of nm |
| [137] | SW-PAM | Microvasculature network | 42.6 | 1 | 40 k | 532 | 320 nm | a hundred of nm |
| [93] | SW-PAM | Microvasculature network | 41 | 1 | – | 532 | 270 nm | hundreds of nm |
| [83] | OR-PAM | Whole brain, oxygen saturation, stroke | 40 | 1 | 800 k | 532, 558 | 7 μm | 1.5 mm |
| [140] | OR-PAM | Oxygen saturation, stroke | 35 | 1 | – | 532, 558 | – | – |
| [141] | OR-PAM | Diabetes, oxygen saturation, blood Fow | 50 | 1 | – | 532, 561 | 3.4 μm | – |
| [142] | OR-PAM | Oxygen saturation, lymph mapping, blood flow speed, cancer | 50 | 1 | 4 k | 532, 545, 558, 570, 620/640 | 3.1 μm | 0.8 mm |
| [143] | OR-PAM | Fractional change, glioma | – | 1 | 600 k | 532 | 11.8 μm | – |
| [17] | OR-PAM | Quadruple images, ophthalmic diseases | 31.5 | 1 | – | 532 | 2.4 μm | – |
f, center frequency; PRF, pulse repetition frequency; SW-PAM, subwavelength photoacoustic microscope; OR-PAM, optical-resolution photoacoustic microscope; k, kHz