scholarly journals Speckle-modulating optical coherence tomography in living mice and humans

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Orly Liba ◽  
Matthew D. Lew ◽  
Elliott D. SoRelle ◽  
Rebecca Dutta ◽  
Debasish Sen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Speckle Noise ◽  
Coherent Detection ◽  
Speckle Reduction ◽  
Optical Coherence ◽  
Coherent Noise ◽  
Speckle Patterns ◽  
Reduction Methods ◽  
Diagnostic Capabilities

Abstract Optical coherence tomography (OCT) is a powerful biomedical imaging technology that relies on the coherent detection of backscattered light to image tissue morphology in vivo. As a consequence, OCT is susceptible to coherent noise (speckle noise), which imposes significant limitations on its diagnostic capabilities. Here we show speckle-modulating OCT (SM-OCT), a method based purely on light manipulation that virtually eliminates speckle noise originating from a sample. SM-OCT accomplishes this by creating and averaging an unlimited number of scans with uncorrelated speckle patterns without compromising spatial resolution. Using SM-OCT, we reveal small structures in the tissues of living animals, such as the inner stromal structure of a live mouse cornea, the fine structures inside the mouse pinna, and sweat ducts and Meissner’s corpuscle in the human fingertip skin—features that are otherwise obscured by speckle noise when using conventional OCT or OCT with current state of the art speckle reduction methods.

scholarly journals Optical coherence tomography: how it all began, and present-time diagnostic capabilities

2014 ◽  
Vol 7 (2) ◽  
pp. 60-68 ◽  
Author(s):  
Yuriy Sergeyevich Astakhov ◽  
Svetlana Georgiyevna Belekhova
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Practical Interest ◽  
Detailed Examination ◽  
Modern Method ◽  
Optical Coherence ◽  
Continual Improvement ◽  
Diagnostic Capabilities ◽  
Very High

The optical coherence tomography is a modern method to assist the ophthalmologist examine the eye fundus. Tomographs have a very high resolution and give the ophthalmologist a in real-time mode in vivo a detailed examination of retinal, optic nerve and choroidal structures. A continual improvement of this technique offers great opportunities and is not only of scientific but also of practical interest.

scholarly journals Aperture Phase Modulation with Adaptive Optics: A Novel Approach for Speckle Reduction and Structure Extraction in Optical Coherence Tomography

2018 ◽  
Author(s):  
Pengfei Zhang ◽  
Suman K. Manna ◽  
Eric B. Miller ◽  
Yifan Jian ◽  
Ratheesh Kumar Meleppat ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Adaptive Optics ◽  
Phase Modulation ◽  
Imaging System ◽  
Speckle Pattern ◽  
Speckle Noise ◽  
Image Resolution ◽  
Speckle Reduction ◽  
Universal Method ◽  
Optical Coherence

Abstract:Speckle is an inevitable consequence of the use of coherent light in optical coherence tomography (OCT), and often acts as noise that obscures micro-structures of biological tissue. We here present a novel method of suppressing speckle noise intrinsically compatible with adaptive optics (AO) in OCT system: by modulating the phase inside the imaging system pupil aperture with a segmented deformable mirror, thus producing minor perturbations in the point spread function (PSF) to create un-correlated speckle pattern between B-scans, and further averaging to wash out the speckle but maintain the structures. It is a well-controlled and universal method which can efficiently determine the optimal range of phase modulation that minimizing speckle noise while maximizing image resolution and signal strength for different systems and/or samples. As an active method, its effectiveness and efficiency were demonstrated by both ex-vivo non-biological and in-vivo biological applications.

scholarly journals A high-accuracy and high-efficiency digital volume correlation method to characterize in-vivo optic nerve head biomechanics from optical coherence tomography

2021 ◽  
Author(s):  
Fuqiang Zhong ◽  
Junchao Wei ◽  
Yi Hua ◽  
Bo Wang ◽  
Juan Reynaud ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Gaussian Noise ◽  
High Efficiency ◽  
Speckle Noise ◽  
High Accuracy ◽  
Digital Volume Correlation ◽  
Optical Coherence

In-vivo optic nerve head (ONH) biomechanics characterization is emerging as a promising way to study eye physiology and pathology. We propose a high-accuracy and high-efficiency digital volume correlation (DVC) method for the purpose of characterizing the in-vivo ONH deformation from volumes acquired by optical coherence tomography (OCT). Using a combination of synthetic tests and analysis of OCTs from monkey ONHs subjected to acute and chronically elevated intraocular pressure, we demonstrate that our proposed methodology overcomes several challenges for conventional DVC methods. First, it accounts for large ONH rigid body motion in the OCT volumes which could otherwise lead to analysis failure; second, sub-voxel accuracy displacement can be guaranteed despite high noise and low image contrast of some OCT volumes; third, computational efficiency is greatly improved, such that the memory consumption of our method is substantially lower than with conventional methods; fourth, we introduce a parameter measuring displacements confidence. Test of image noise effects showed that the proposed DVC method had displacement errors smaller than 0.028 voxels with speckle noise and smaller than 0.037 voxels with Gaussian noise; The absolute (relative) strain errors in the three directions were lower than 0.0018 (4%) with speckle noise and than 0.0045 (8%) with Gaussian noise. Compared with conventional DVC methods, the proposed DVC method had substantially improved overall displacement and strain errors under large body motions (lower by up to 70%), with 75% lower computation times, while saving about 30% memory. The study thus demonstrates the potential of the proposed technique to investigate ONH biomechanics.

258: Diagnosis and Intraoperative Staging of Bladder Disease by in-vivo Optical Coherence Tomography (OCT)

2004 ◽  
Vol 171 (4S) ◽  
pp. 68-68 ◽  
Author(s):  
Markus D. Sachs ◽  
Dmitry Daniltchenko ◽  
Eva Lankenau ◽  
Frank Koenig ◽  
Gerion Huettmann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Bladder Disease

scholarly journals Evaluating Retinal and Choroidal Perfusion Changes after Isometric and Dynamic Activity Using Optical Coherence Tomography Angiography

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 808
Author(s):  
Max Philipp Brinkmann ◽  
Nikolas Xavier Kibele ◽  
Michelle Prasuhn ◽  
Vinodh Kakkassery ◽  
Mario Damiano Toro ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Isometric Exercise ◽  
Dynamic Exercise ◽  
Exercise Heart Rate ◽  
Optical Coherence ◽  
Dynamic Activity ◽  
Capillary Plexus ◽  
Choroidal Perfusion

Optical coherence tomography angiography (OCTA) is a non-invasive tool for imaging and quantifying the retinal and choroidal perfusion state in vivo. This study aimed to evaluate the acute effects of isometric and dynamic exercise on retinal and choroidal sublayer perfusion using OCTA. A pilot study was conducted on young, healthy participants, each of whom performed a specific isometric exercise on the first day and a dynamic exercise the day after. At baseline and immediately after the exercise, heart rate (HR), mean arterial pressure (MAP), superficial capillary plexus perfusion (SCPP), deep capillary plexus perfusion (DCPP), choriocapillaris perfusion (CCP), Sattlers’s layer perfusion (SLP), and Haller’s layer perfusion (HLP) were recorded. A total of 34 eyes of 34 subjects with a mean age of 32.35 ± 7.87 years were included. HR as well as MAP increased significantly after both types of exercise. Both SCPP and DCPP did not show any significant alteration due to isometric or dynamic exercise. After performing dynamic exercise, CCP, SLP, as well as HLP significantly increased. Changes in MAP correlated significantly with changes in HLP after the dynamic activity. OCTA-based analysis in healthy adults following physical activity demonstrated a constant retinal perfusion, supporting the theory of autoregulatory mechanisms. Dynamic exercise, as opposed to isometric activity, significantly changed choroidal perfusion. OCTA imaging may represent a novel and sensitive tool to expand the diagnostic spectrum in the field of sports medicine.

scholarly journals Quantitative Swept-Source Optical Coherence Tomography of Early Enamel Erosion in vivo

2017 ◽  
Vol 51 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Rupert S. Austin ◽  
Maisalamah Haji Taha ◽  
Frederic Festy ◽  
Richard Cook ◽  
Manoharan Andiappan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Volunteers ◽  
Orange Juice ◽  
Signal Intensity ◽  
Surface States ◽  
Enamel Surface ◽  
Optical Coherence ◽  
Swept Source ◽  
Water Rinsing

Swept-source optical coherence tomography (SS-OCT) shows potential for the in vivo quantitative evaluation of micro-structural enamel surface phenomena occurring during early erosive demineralization. This randomized controlled single-blind cross-over clinical study aimed to evaluate the use of SS-OCT for detecting optical changes in the enamel of 30 healthy volunteers subjected to orange juice rinsing (erosive challenge) in comparison to mineral water rinsing (control), according to wiped and non-wiped enamel surface states. Participants were randomly allocated to 60 min of orange juice rinsing (pH 3.8) followed by 60 min of water rinsing (pH 6.7) and vice versa, with a 2-week wash-out period. In addition, the labial surfaces of the right or left maxillary incisors were wiped prior to SS-OCT imaging. An automated ImageJ algorithm was designed to analyse the back-scattered OCT signal intensity (D) after orange juice rinsing compared to after water rinsing. D was quantified as the OCT signal scattering from the 33 µm sub-surface enamel, normalised by the total OCT signal intensity entering the enamel. The back-scattered OCT signal intensity increased by 3.1% (95% CI 1.1-5.1%) in the wiped incisors and by 3.5% (95% CI 1.5-5.5%) in the unwiped incisors (p < 0.0001). Wiping reduced the back-scattered OCT signal intensity by 1.7% (95% CI -3.2 to -0.3%; p = 0.02) in comparison to the unwiped enamel surfaces for both rinsing solutions (p = 0.2). SS-OCT detected OCT signal changes in the superficial sub-surface enamel of maxillary central incisor teeth of healthy volunteers after orange juice rinsing.

In vivo cellular optical coherence tomography imaging

1998 ◽  
Vol 4 (7) ◽  
pp. 861-865 ◽  
Author(s):  
Stephan A. Boppart ◽  
Brett E. Bouma ◽  
Costas Pitris ◽  
James F. Southern ◽  
Mark E. Brezinski ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Tomography Imaging ◽  
Optical Coherence Tomography Imaging

scholarly journals Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Radiation Dose ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Optical Coherence ◽  
X Rays ◽  
High Quality ◽  
X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

scholarly journals Multi-center clinical study using optical coherence tomography for evaluation of cervical lesions in-vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenchen Ren ◽  
Xianxu Zeng ◽  
Zhongna Shi ◽  
Chunyan Wang ◽  
Huifen Wang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Precancerous Lesions ◽  
Diagnostic Value ◽  
Optical Coherence ◽  
Cervical Lesions ◽  
In Vivo Evaluation ◽  
Histological Sections ◽  
Histological Images

AbstractIn this prospective study of an in-vivo cervical examination using optical coherence tomography (OCT), we evaluated the diagnostic value of non-invasive and real-time OCT in cervical precancerous lesions and cancer diagnosis, and determined the characteristics of OCT images. 733 patients from 5 Chinese hospitals were inspected with OCT and colposcopy-directed biopsy. The OCT images were compared with the histological sections to find out the characteristics of various categories of lesions. The OCT images were also interpreted by 3 investigators to make a 2-class classification, and the results were compared against the pathological results. Various structures of the cervical tissue were clearly observed in OCT images, which matched well with the corresponding histological sections. The OCT diagnosis results delivered a sensitivity of 87.0% (95% confidence interval, CI 82.2–90.7%), a specificity of 84.1% (95% CI 80.3–87.2%), and an overall accuracy of 85.1%. Both good consistency of OCT images and histological images and satisfactory diagnosis results were provided by OCT. Due to its features of non-invasion, real-time, and accuracy, OCT is valuable for the in-vivo evaluation of cervical lesions and has the potential to be one of the routine cervical diagnosis methods.

Sign in / Sign up

Export Citation Format

Share Document