Table 4.
Summary of functional photoacoustic computed tomography systems’ specifications
| Ref. | System scale | Functionality and application | Transducer | Laser | Lateral resolution (μm) | Imaging depth (mm) | ||
|---|---|---|---|---|---|---|---|---|
| f (MHz) | Element | PRF | Wavelength (nm) | |||||
| [87] | PACT | Oxygen saturation | 2 | 1024 | 20 | 750, 850 | 380 | 12.8 |
| [86] | PACT | Cerebral hemodynamics; HbO2, HbR, HbT, SO2 | 5.4 | 512 | 200 | 532, 594 | 170 | 3.5 |
| [171] | PACT | Cerebral hemodynamics; HbO2, HbR, HbT, SO2 | 7 | 512 | 20 (100/5) | 700, 730, 755, 800, 850 | 133 | 4 |
| [172] | PACT | Cerebral sensory response hemodynamics; HbO2, HbR, HbT, SO2 | 5 | 384 | 10 (50/5) | 700, 730, 755, 800, 850 | 163 | 4 |
| [173] | PACT | liver steatosis; Normalized ratio spectrum, normalized optoacoustic ratio at 930 nm | 5/4 | 256/256 | 10/25 | 680–960 (10 nm step)/700–970 (10 nm step) | 300 | 34 |
| [84] | PACT | liver steatosis; Liver mask volume, vessel number density, vessel volume occupancy, angiographic irregularity, speed of sound | 2.25 | 4 × 256 | 12.5 | 1064 | 380 | 12 |
| [120] | PACT | Venous flow hemodynamics; flow speed, flow vector map, fractional speed change | 13–24 | 256 | 10/20/100 | 1064/670–1070 | 125 | 5.5 |
f, center frequency; PRF, pulse repetition frequency; PACT, photoacoustic computed tomography