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.

Real-time eye motion correction in phase-resolved OCT angiography with tracking SLO

Abstract: In phase-resolved OCT angiography blood flow is detected from phase changes in between A-scans that are obtained from the same location. In ophthalmology, this technique is vulnerable to eye motion. We address this problem by combining inter-B-scan phase-resolved OCT angiography with real-time eye tracking. A tracking scanning laser ophthalmoscope (TSLO) at 840 nm provided eye tracking functionality and was combined with a phase-stabilized optical frequency domain imaging (OFDI) system at 1040 nm. Real-time eye tracking corrected eye drift and prevented discontinuity artifacts from (micro)saccadic eye motion in OCT angiograms. This improved the OCT spot stability on the retina and consequently reduced the phase-noise, thereby enabling the detection of slower blood flows by extending the inter-B-scan time interval. In addition, eye tracking enabled the easy compounding of multiple data sets from the fovea of a healthy volunteer to create high-quality eye motion artifact-free angiograms. High-quality images are presented of two distinct layers of vasculature in the retina and the dense vasculature of the choroid. Additionally we present, for the first time, a phase-resolved OCT angiogram of the mesh-like network of the choriocapillaris containing typical pore openings.

Optical coherence tomography: high resolution intravascular imaging to evaluate vascular healing after coronary stenting.

Abstract: The risk of late stent thrombosis represents a major concern for patients treated with drug-eluting stents (DES). Delayed healing and incomplete stent coverage were commonly observed in pathologic specimens of vessels treated with DES. In-situ assessment of the stent coverage has been limited by the low spatial resolution of current image modalities. Optical coherence tomography (OCT) enables real-time, full tomographic, in-vivo visualization of coronary vessel microstructure. Struts coverage and vessel response of DES compared to BMS are the most immediate clinical applications of OCT. Thickness of coverage and strut apposition can be quantified at micron-scale level with a resolution 10–30 times higher than conventional intravascular ultrasound. Current clinical experience demonstrates the high level of accuracy of OCT in evaluating the heterogeneity of vascular healing following DES implantation. Neointimal coverage at strut level assessed by OCT seems a reasonable intermediate endpoint to quickly scrutinize in preregistration studies the safety profile of the next generation of DES. Major limitations of current OCT technology are shallow depth of light penetration and the need to occlude the vessel for blood removal. Second generation forms of OCT, which allow images to be recorded faster (≅10 times) during a nonocclusive flush, have been recently developed. Full, quick scan of multiple and long stent without occlusion balloon is possible. Further technical advancements are expected to provide sharper images with additional contrast and tissue texture characterization. The value of these improvements must be gauged by the degree of impact in DES technology and patient care. © 2008 Wiley-Liss, Inc.

Impact of Frequency-Domain Optical Coherence Tomography Guidance for Optimal Coronary Stent Implantation in Comparison With Intravascular Ultrasound Guidance

Abstract: Background—Frequency-domain optical coherence tomography (FD-OCT) is a novel, high resolution intravascular imaging modality. Intravascular ultrasound (IVUS) is a widely used conventional imaging modality for achieving optimal stent deployment. The aim of this study was to evaluate the impact of FD-OCT guidance for coronary stent implantation compared with IVUS guidance. Methods and Results—A total of 70 patients with de novo coronary artery lesions and either unstable or stable angina pectoris were enrolled in this randomized study (optical coherence tomography [OCT] group: n=35, IVUS group: n=35). In the OCT group, stent implantation was performed under FD-OCT guidance alone and final stent expansion was evaluated by IVUS. In the IVUS group, conventional IVUS guidance was used and final stent apposition was evaluated by FD-OCT. There were no significant differences regarding the procedural, fluoroscopy time, and contrast volume. Although device and clinical success rates also were similar, the visibilit...

Deep learning approach for the detection and quantification of intraretinal cystoid fluid in multivendor optical coherence tomography.

Abstract: We developed a deep learning algorithm for the automatic segmentation and quantification of intraretinal cystoid fluid (IRC) in spectral domain optical coherence tomography (SD-OCT) volumes independent of the device used for acquisition. A cascade of neural networks was introduced to include prior information on the retinal anatomy, boosting performance significantly. The proposed algorithm approached human performance reaching an overall Dice coefficient of 0.754 ± 0.136 and an intraclass correlation coefficient of 0.936, for the task of IRC segmentation and quantification, respectively. The proposed method allows for fast quantitative IRC volume measurements that can be used to improve patient care, reduce costs, and allow fast and reliable analysis in large population studies.

Imaging the Internal Structure of the Rat Cochlea Using Optical Coherence Tomography at 0.827 μm and 1.3 μm

Abstract: Objective The purpose of this study was to use high-speed optical coherence tomography (OCT) to obtain cross-sectional images of the rat cochlea. Study design and methods The cochleae of Sprague- Dawley rats were imaged within 2 to 4 hours after death. Specimens were prepared by removing the bulla to expose the mesotympanum; some images were obtained in intact temporal bones removed from the cranium. The central element of an OCT imaging device is a Michelson interferometer combined with a low-coherence light source. This study used 2 OCT systems with different light sources: 1) a semiconductor optical amplifier operating and 2) a superluminescent diode with peak emissions wavelengths of 1.3 μm and 827 nm, respectively. Images (1.87 × 2.00 mm or 1.87 × 1.00 mm, 10 × 10 μm pixel resolution) were acquired at a frame rate of 1 Hz. Cross-sectional images at 100-μm increments were obtained from a medial-to-lateral direction. Results The scala vestibuli, scala media, scala tympani, modiolus, spiral ligament, and several turns of the cochlea were identified. Conclusion These images reflect the ability of OCT to provide images of the internal cochlea structure with micron scale resolution and at near-real time frame rates.