Abstract
Photoacoustic imaging (PAI) was performed to evaluate oxygen saturation (sO(2)) of blood-mimicking phantoms, femoral arteries in beagles, and radial arteries in humans at various sO(2) plateaus. The accuracy (root mean square error, RMSE) of PAI sO(2) compared with reference sO(2) was calculated. In blood-mimicking phantoms, PAI achieved an accuracy of 1.49% and a mean absolute error (MAE) of 1.09% within 25 mm depth, and good linearity (R = 0.968; p < 0.001) was obtained between PAI sO(2) and reference sO(2). In canine femoral arteries, PAI achieved an accuracy of 2.16% and an MAE of 1.58% within 8 mm depth (R = 0.965; p < 0.001). In human radial arteries, PAI achieved an accuracy of 3.97% and an MAE of 3.28% in depth from 4 to 14 mm (R = 0.892; p < 0.001). For PAI sO(2) evaluation at different depths in healthy volunteers, the RMSE accuracy of PAI sO(2) increased from 2.66% to 24.96% with depth increasing from 4 to 14 mm. Through the multiscale method, we confirmed the feasibility of the hand-held photoacoustic/ultrasound (PA/US) in evaluating sO(2). These results demonstrate the potential clinical value of PAI in evaluating blood sO(2). Consequently, protocols for verifying the feasibility of medical devices based on PAI may be established.