Split-spectrum dual-domain phase-intensity fusion optical coherence tomography angiography

Optical coherence tomography angiography (OCTA) provides micrometer-resolution maps of the retinal microvasculature. However, even slight ocular motion can introduce pronounced motion artifacts that degrade image quality. To overcome this, we present a split-spectrum dual-domain phase-intensity fusion algorithm. The approach mitigates low-frequency phase drift in the time domain, corrects systematic phase errors in the frequency domain, and integrates complementary amplitude-decorrelation and phase-difference information. Independent processing of spectral sub-bands further enhances the flow signal-to-noise ratio. In vivo mouse-retina imaging shows that, even without additional inter-frame registration, the method markedly improves angiographic contrast and signal fidelity while greatly reducing motion artifacts. This technique provides a reliable path to high-quality OCTA under dynamic conditions or at low acquisition frame rates.