A comparison of cross-correlation-based and phasecorrelation-based image registration algorithms for optical coherence tomographic angiography

A large field of view is in high demand for disease diagnosis in clinical applications of optical coherence tomography(OCT)and OCT angiography(OCTA)imaging.Due to limits on the optical scanning range,the scanning speed,or the data processing speed,only a relatively small region could be acquired and processed for most of the current clinical OCT systems at one time and could generate a mosaic image of multiple adjacent small-region images with registration algorithms for disease analysis.In this work,we investigated performing cross-correlation(instead of phase-correlation)in the workflow of the Fourier–Mellin transform(FMT)method(called dual-cross-correlation-based translation and rotation registration,DCCTRR)for calculating translation and orientation offsets and compared its performance to the FMT method used on OCTA images alignment.Both phantom and in vivo experiments were implemented for comparisons,and the results quantitatively demonstrate that DCCTRR can align OCTA images with a lower overlap rate,which could improve the scanning efficiency of large-scale imaging in clinical applications.

Advances in the application of optical coherence tomography in the assessment of ischemic stroke

Ischemic stroke has high morbidity,mortality,disability rate and recurrence.It is the one of the main diseases that threaten people's health in China.Its etiology,pathogenesis,and reaction mechanism has been the research hotspot and difficulty of related studies have shown that the optical coherence tomography technology is an effective measure to evaluate ischemic cerebral apoplexy.Optical coherence tomography(OCT)is a gradually developed and mature imaging technology in recent years,and there are related studies on internal carotid artery,retina and coronary artery.Based on the above background,this paper reviews the research progress of optical coherence tomography in the assessment of the etiology,pathogenesis and response mechanism of ischemic stroke.