Evaluation of scan protocols for optical coherence tomography angiography

Optical coherence tomography angiography (OCTA) is a label-free, high-resolution imaging technique for detecting blood flow based on optical coherence tomography (OCT) and time-series signal analysis. In OCTA, the time-series signals at the same position are captured, and the changes in the signals are analyzed to detect the blood flow. In this study, we evaluated different scan protocols for the OCTA regarding image quality and sampling time, including the dense A-scan, dense B-scan, and multiple B-scan protocols. In the dense A-scan or the dense B-scan protocols, the beam continues scanning with a slight change between adjacent positions. Whereas, the scan beam will pause at each slow scan position to repeatedly capture the B-scans in the multiple B-scan protocol. After the time-series signals were captured using different scan protocols and analyzed using an OCTA algorithm, the vasculature of the rat tissue was visualized. The image quality was analyzed to assess the efficiency of the scan protocols. The quantitative evaluation of the scan protocols allows for optimizing the sampling schemes in the OCTA imaging of biological tissues.