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Optical coherence tomography

About: Optical coherence tomography is a research topic. Over the lifetime, 19051 publications have been published within this topic receiving 477433 citations. The topic is also known as: optical coherent tomography.


Papers
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Journal ArticleDOI
TL;DR: A B-spline based free form deformation method is used to automatically register variance images from multiple volumes to obtain a motion-free composite image of the retinal vessels and extends this technique to automatically mosaic individual vascular images into a widefield image ofThe retinal vasculature.
Abstract: Variance processing methods in Fourier domain optical coherence tomography (FD-OCT) have enabled depth-resolved visualization of the capillary beds in the retina due to the development of imaging systems capable of acquiring A-scan data in the 100 kHz regime. However, acquisition of volumetric variance data sets still requires several seconds of acquisition time, even with high speed systems. Movement of the subject during this time span is sufficient to corrupt visualization of the vasculature. We demonstrate a method to eliminate motion artifacts in speckle variance FD-OCT images of the retinal vasculature by creating a composite image from multiple volumes of data acquired sequentially. Slight changes in the orientation of the subject’s eye relative to the optical system between acquired volumes may result in non-rigid warping of the image. Thus, we use a B-spline based free form deformation method to automatically register variance images from multiple volumes to obtain a motion-free composite image of the retinal vessels. We extend this technique to automatically mosaic individual vascular images into a widefield image of the retinal vasculature.

147 citations

Journal ArticleDOI
TL;DR: It is believed that this new type of handheld OCT device and system has the potential to be an efficient point-of-care imaging tool in primary care medicine.
Abstract: The goal of this study is to develop an advanced point-of-care diagnostic instrument for use in a primary care office using handheld optical coherence tomography (OCT). This system has the potential to enable earlier detection of diseases and accurate image-based diagnostics. Our system was designed to be compact, portable, user-friendly, and fast, making it well suited for the primary care office setting. The unique feature of our system is a versatile handheld OCT imaging scanner which consists of a pair of computer-controlled galvanometer-mounted mirrors, interchangeable lens mounts, and miniaturized video camera. This handheld scanner has the capability to guide the physician in real time for finding suspicious regions to be imaged by OCT. In order to evaluate the performance and use of the handheld OCT scanner, the anterior chamber of a rat eye and in vivo human retina, cornea, skin, and tympanic membrane were imaged. Based on this feasibility study, we believe that this new type of handheld OCT device and system has the potential to be an efficient point-of-care imaging tool in primary care medicine.

146 citations

Journal ArticleDOI
TL;DR: Computer-driven, automated measurement of retinal thickness within 500 microns of fixation needs to be refined and its reproducibility reassessed in this region.
Abstract: BACKGROUND AND OBJECTIVE: To determine the reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography (OCT). PATIENTS AND METHODS: Multiple 3.20-mm vertical cross-sectional images through the center of fixation of consecutive patients with normal results on ocular examinations were obtained. Each image was divided into seven 320-micron segments. Regional retinal thicknesses for each section were measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes (observer-independent measurement) of the computer software. RESULTS: Eighteen right eyes were studied. The mean coefficient of variation was less than 10% for all locations using the manually assisted method (average standard deviation less than 17 microns [range 9 to 16 microns]). The automated method was less reliable, with a coefficient of variation greater than 10% for locations within 500 microns of fixation. Automated measurements at fixation were the least reproducible because of poor internal limiting membrane reflectivity. CONCLUSION: OCT is capable of reproducible measurement of retinal thickness in normal eyes. Computer-driven, automated measurement of retinal thickness within 500 microns of fixation needs to be refined and its reproducibility reassessed in this region.

145 citations

Patent
22 Jan 2002
TL;DR: A method and apparatus for extracting the vector optical properties of biological samples with micron-scale resolution in three dimensions, using polarization-sensitive optical coherence tomography (PS-OCT) was proposed in this article.
Abstract: A method and apparatus for extracting the vector optical properties of biological samples with micron-scale resolution in three dimensions, using polarization-sensitive optical coherence tomography (PS-OCT) The method measures net retardance, net fast axis, and reflexivity Polarization sensing is accomplished by illuminating the sample with at least three separate polarization states, using consecutive acquisitions of the same pixel, A-scan, or B-scan The method can be implemented using non-polarization-maintaining fiber and a single detector This PS-OCT method reported measures fast axis explicitly In a calibration test of the system, net retardance was measured with an average error of 75° (standard deviation 22°) over the retardance range 0° to 180°, and fast axis with average error of 48° over the range 0° to 180°

145 citations

Book ChapterDOI
14 Aug 2019
TL;DR: Optical coherence tomography (OCT) is a non-invasive technique for cross-sectional tissue imaging as mentioned in this paper, which typically uses light in the near-infrared spectral range which has a penetration depth of several hundred microns.
Abstract: Optical coherence tomography (OCT) is a non-invasive technique for cross-sectional tissue imaging. It typically uses light in the near-infrared spectral range which has a penetration depth of several hundred microns in tissue. The backscattered light is measured with an interferometric set-up to reconstruct the depth profile of the sample at the selected location. A scanning OCT beam allows for acquisition of cross-sectional images of the tissue structure. Different technical methods are introduced and compared regarding their properties like sensitivity, imaging speed and penetration depth. Regardless of the technical realization, axial resolution and imaging range of an OCT system are determined by light source and detector characteristics. Combining retinal OCT with a confocal scanning laser ophthalmoscope allows for motion tracking during acquisition and to examine the exact same position at any time again. Segmentation of features is the basis for automatic depth measurements and standardized measurements to be compared with normative databases. New trends show the ability of functional OCT to image flow, polarizing properties of tissue and even mechanical properties like elasticity. Recent approaches to improve the resolution and the acquisition speed show the ongoing research interest in OCT.

145 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,805
20223,557
2021907
20201,074
20191,127
20181,113