الفهرس 
Principles of OCT and OCT AngiographyOnly 14 pages are availabe for public view
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Abstract
Optical coherence tomography (OCT) is an imaging system designed to acquire high resolution cross-sectional retinal images. The technique is analogous to ultrasonography, but the tomographic OCT image is an intensity map of light back-scattered or reflected from tissue structures.
OCT is based on a classical principle of optics, which is known as low-coherence interferometry. Low-coherence interferometry is a simple method, which can be used to precisely measure distances between objects by measuring Light reflected from them.
Optical coherence tomography angiography (OCTA) is a new non-invasive imaging technique that employs motion contrast imaging to high-resolution volumetric blood flow information generating angiographic images in a matter of seconds.
OCTA compares the decorrelation signal (differences in the backscattered OCT signal intensity or amplitude) between sequential OCT b-scans taken at precisely the same cross-section in order to construct a map of bA split-spectrum amplitude decorrelation angiography (SSADA) algorithm use the natural flow as the target of the algorithm, and then,no need for injection of any dye to obtain the image of retinochoroidal vascular network. The flow is detected by comparison of same acquisitions in different times. SSADA algorithm is based on amplitude decorrelation.
key words : Optical Coherence TomographyAngiography (OCTA) as a New Modality for Posterior Segment Imaging