Pulse photothermal optical coherence tomography for multimodal hemodynamic imaging.

To realize multimodal hemodynamic imaging, pulse photothermal optical coherence tomography (P-PTOCT) is proposed in this Letter to solve the separation problem of photothermal phase and Doppler phase, which is difficult to solve in traditional PTOCT. This technique can obtain blood flow distribution, light absorption distribution, and concentration images simultaneously. Based on the difference between pulse photothermal phase and Doppler phase, we propose an even number differential demodulation algorithm that can separate the photothermal phase and Doppler phase from the same scanning data set. The separated photothermal phase can characterize the trend of drug concentration, which provides the possibility for quantitative measurement of plasma concentration. The combination of photothermal phase and Doppler phase is helpful for potential clinical research on hemodynamics of cerebral ischemia and provides a technical reference for the rapid acquisition of perfusion volume and plasma concentration at one time.