Detection and registration of vessels of fundus and OCT images using curevelet analysis

In recent years, advanced analysis of retinal images, has built automatic systems for diagnosis of various diseases. These devices help us save both time and money. The new techniques of 3D-Optical Coherence Tomography (OCT) imaging is very useful for detecting retinal pathologic changes in various diseases and determining retinal thickness abnormalities. Fundus color images have been used for several years for detecting retinal abnormalities too. If the two image modalities were combined, the resulted image would be more informative because some abnormalities such as drusen, geographic atrophy, and macular hemorrhages are detected in color fundus images but the exact morphology and localization of these abnormalities are released in OCT images. The first step to combine the different modalities is to register color fundus images with OCT projection. Ten eyes were imaged in this study with Topcon 3D OCT-1000 instrument. This instrument is used to observe the retina, take fundus and tomograms and record them. An en face representation of OCT reflectivity can be registered with color fundus photography. In this study curvelet transform is used to extract vessels for both modalities. Then the extracted vessels from two modalities are registered together. In this way more blood vessels can be obtained and the results would be more informative.