Automated retinal shadow compensation of optical coherence tomography images.
نویسندگان
چکیده
We present an automated numerical method of compensating for retinal shadows in the choroid. In this method, signal extinction caused by retinal vessels is estimated by subtracting median A-scans obtained from beneath the retinal vessels and A-scans from the surrounding area. Adding the obtained offset vector to A-scans from beneath the retinal vessels allows compensating for shadows in the choroid. In vivo imaging of the human eye was performed by 840-nm-band standard resolution spectral domain optical coherence tomography (SD-OCT), and choroidal vasculature projection images were calculated. Removal of retinal shadows distinctly improved the readability of choroidal images.
منابع مشابه
Speckle Noise Reduction for the Enhancement of Retinal Layers in Optical Coherence Tomography Images
Introduction One of the most important pre-processing steps in optical coherence tomography (OCT) is reducing speckle noise, resulting from multiple scattering of tissues, which degrades the quality of OCT images. Materials and Methods The present study focused on speckle noise reduction and edge detection techniques. Statistical filters with different masks and noise variances were applied on ...
متن کاملEvaluation of Optical Coherence Tomography Angiography Findings in Patients with Branch Retinal Vein Occlusion
Purpose: To analyze the correlation of optical coherence tomography angiography (OCTA) findings with visual acuity (VA) in patients with branch retinal vein occlusion (BRVO). Methods: This cross-sectional study was performed on 20 eyes of 20 patients with unilateral BRVO involving the macula referred to the ophthalmology clinic of Rassoul Akram Hospital. OCTA imaging was conducted for all patie...
متن کاملShadow removal and contrast enhancement in optical coherence tomography images of the human optic nerve head.
PURPOSE To improve the quality of optical coherence tomography (OCT) images of the optic nerve head (ONH). METHODS Two algorithms were developed, one to compensate for light attenuation and the other to enhance contrast in OCT images. The former was borrowed from developments in ultrasound imaging and was proven suitable with either time- or spectral-domain OCT. The latter was based on direct...
متن کاملRetinal Ganglion Cell Complex in Alzheimer Disease: Comparing Ganglion Cell Complex and Central Macular Thickness in Alzheimer Disease and Healthy Subjects Using Spectral Domain-Optical Coherence Tomography
Introduction: Alzheimer disease (AD) is the most common form of dementia worldwide. The modalities to diagnose AD are generally expensive and limited. Both the central nervous system (CNS) and the retina are derived from the cranial neural crest; therefore, changes in retinal layers may reflect changes in the CNS tissue. Optical coherence tomography (OCT) machine can show delicate retinal layer...
متن کاملEffects of Laser Physical Parameters on Lesion Size in Retinal Photocoagulation Surgery: Clinical OCT and Experimental Study
Introduction: The aim of the present study was to determine burn intensity in retinal laser photocoagulation based on laser parameters; wavelength, power, beam size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera, physical eye model and computer simulation in a clinical study.Materials and Methods: Participants were 10 adult patients between 50-80 years with prolifer...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of biomedical optics
دوره 14 1 شماره
صفحات -
تاریخ انتشار 2009