scholarly journals Interferometer-in-Spectrometer for High-Resolution Optical Coherence Tomography

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Lishuang Liu ◽  
Jun Xie ◽  
Linbo Liu ◽  
Si Chen
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Axial Resolution ◽  
Testing Method ◽  
Spectral Domain Oct ◽  
Standard Design

Ultrahigh-resolution optical coherence tomography provides an axial resolution of 1-2 μm for resolving cellular structures of biological tissues critical for the diagnosis of diseases. However, it requires a relatively large spectral bandwidth which is not supported by the key components of the imaging system. We propose a novel spectral-domain OCT design, termed interferometer-in-spectrometer, which is able to compensate the bandwidth limitations of the grating and the line scan sensor by spectral shaping without compromising the signal intensity and adding the system cost. The advantage of axial resolution and ranging depth over the standard design is experimentally validated using the standard testing method and fresh swine cornea ex vivo. Moreover, opportunities that opened up by this new scheme for improving the performances of spectral-domain OCT are also discussed.

scholarly journals Morpho-molecular ex vivo detection and grading of non-muscle-invasive bladder cancer using forward imaging probe based multimodal optical coherence tomography and Raman spectroscopy

The Analyst ◽  
2020 ◽  
Vol 145 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Fabian Placzek ◽  
Eliana Cordero Bautista ◽  
Simon Kretschmer ◽  
Lara M. Wurster ◽  
Florian Knorr ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Coherence Tomography ◽  
Imaging System ◽  
Ex Vivo ◽  
Large Field ◽  
Optical Coherence ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Muscle Invasive

Characterization of bladder biopsies, using a combined fiber optic probe-based optical coherence tomography and Raman spectroscopy imaging system that allows a large field-of-view imaging and detection and grading of cancerous bladder lesions.

scholarly journals Design and Implementation Guidelines for a Modular Spectral-Domain Optical Coherence Tomography Scanner

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Farid Atry ◽  
Israel Jacob De La Rosa ◽  
Kevin R. Rarick ◽  
Ramin Pashaie
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Optical Design ◽  
Spectral Domain ◽  
Design Parameters ◽  
Optical Coherence ◽  
Custom Made ◽  
Essential Knowledge ◽  
Sd Oct

In the past decades, spectral-domain optical coherence tomography (SD-OCT) has transformed into a widely popular imaging technology which is used in many research and clinical applications. Despite such fast growth in the field, the technology has not been readily accessible to many research laboratories either due to the cost or inflexibility of the commercially available systems or due to the lack of essential knowledge in the field of optics to develop custom-made scanners that suit specific applications. This paper aims to provide a detailed discussion on the design and development process of a typical SD-OCT scanner. The effects of multiple design parameters, for the main optical and optomechanical components, on the overall performance of the imaging system are analyzed and discussions are provided to serve as a guideline for the development of a custom SD-OCT system. While this article can be generalized for different applications, we will demonstrate the design of a SD-OCT system and representative results for in vivo brain imaging. We explain procedures to measure the axial and transversal resolutions and field of view of the system and to understand the discrepancies between the experimental and theoretical values. The specific aim of this piece is to facilitate the process of constructing custom-made SD-OCT scanners for research groups with minimum understanding of concepts in optical design and medical imaging.

scholarly journals Retinal Damage in Multiple Sclerosis Disease Subtypes Measured by High-Resolution Optical Coherence Tomography

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Timm Oberwahrenbrock ◽  
Sven Schippling ◽  
Marius Ringelstein ◽  
Falko Kaufhold ◽  
Hanna Zimmermann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Neuritis ◽  
Large Scale ◽  
Retinal Nerve Fibre Layer ◽  
Spectral Domain ◽  
Healthy Controls ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Spectral Domain Oct ◽  
Rnfl Thickness

Background.Optical coherence tomography (OCT) has facilitated characterisation of retinal alterations in MS patients. Only scarce and in part conflicting data exists on different MS subtypes.Objective.To analyse patterns of retinal changes in different subtypes of MS with latest spectral-domain technology.Methods.In a three-centre cross-sectional study 414 MS patients and 94 healthy controls underwent spectral-domain OCT examination.Results.Eyes of MS patients without a previous optic neuritis showed a significant reduction of both retinal nerve fibre layer (RNFL) thickness and total macular volume (TMV) compared to healthy controls independent of the MS subtype (P<0.001for all subtypes). RNFL thickness was lower in secondary progressive MS (SPMS) eyes compared to relapsing-remitting MS (RRMS) eyes (P=0.007), and TMV was reduced in SPMS and primary progressive MS (PPMS) eyes compared to RRMS eyes (SPMS:P=0.039, PPMS:P=0.005). Independent of the subtype a more pronounced RNFL thinning and TMV reduction were found in eyes with a previous optic neuritis compared to unaffected eyes.Conclusion.Analysis of this large-scale cross-sectional dataset of MS patients studied with spectral-domain OCT confirmed and allows to generalize previous findings. Furthermore it carves out distinct patterns in different MS subtypes.

Retinal Nerve Fiber Layer Imaging with Spectral-domain Optical Coherence Tomography (OCT)—A Review of the Cirrus HD-OCT

2011 ◽  
Vol 04 (01) ◽  
pp. 12 ◽  
Author(s):  
Elaine To ◽  
Dennis Lam ◽  
Christopher Kai-shun Leung ◽  
◽  
◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Nerve Fiber ◽  
Retinal Nerve Fiber Layer ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Spectral Domain Oct ◽  
Rnfl Thickness ◽  
Retinal Nerve Fiber

High-speed, high-resolution imaging of the retinal nerve fiber layer (RNFL) with spectral-domain optical coherence tomography (OCT) has become an essential tool for evaluation of glaucoma. The Cirrus HD-OCT (Carl Zeiss Meditec, Inc. Dublin, CA) is a spectral-domain OCT that provides visualization of the distribution pattern and measurement of RNFL abnormalities in a 6x6mm2optic disc region. Analysis of the RNFL thickness deviation map—a color-coded map displaying areas of RNFL abnormalities—detects glaucoma with high sensitivity and specificity. Trend analysis of average and sectorial RNFL thicknesses, and event analysis of the RNFL thickness maps and the RNFL thickness profiles can be used to detect and follow diffuse and focal RNFL progression. RNFL measurement with spectral-domain OCT could provide important information for use in formulating treatment plans and evaluating disease prognosis in the management of glaucoma.

scholarly journals Spectral Domain OCT: An Aid to Diagnosis and Surgical Planning of Retinal Detachments

2011 ◽  
Vol 2011 ◽  
pp. 1-4
Author(s):  
Graham Auger ◽  
Stephen Winder
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Surgical Planning ◽  
Surgical Intervention ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Spectral Domain Oct

Regmatogenous retinal detachments need prompt intervention particularly when macula is on. Unfortunately this is not always easy to ascertain clinically and the chronicity of the event is often muddled in patient's histories. Developments in optical coherence tomography (OCT) have allowed high-resolution axial scans which have enabled the characterisation of retinal changes in retinal detachments. In this paper, we show the changes in retinal morphology observed by spectral domain OCT and how this can be used to plan appropriate surgical intervention.

scholarly journals Quantitative Diagnosis of Colorectal Polyps by Spectral Domain Optical Coherence Tomography

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chen Wang ◽  
Qinqin Zhang ◽  
Xiaojing Wu ◽  
Tao Tang ◽  
Hong Liu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Early Diagnosis ◽  
Colorectal Polyp ◽  
Primary Diagnosis ◽  
Colorectal Polyps ◽  
Spectral Domain ◽  
Scattering Coefficient ◽  
Optical Coherence ◽  
Scattering Coefficients ◽  
Spectral Domain Oct

The principal aim of this study is to investigate the scattering coefficient of colorectal polyp tissues using an optical coherence tomography (OCT) technique. It combines the existing scattering coefficient model and spectral domain OCT to achieve method of early diagnosis of colorectal polyp in hospitals. Seventeen patients were studied, and a total of 1456 data points were extracted by curve-fitting the OCT signals into a confocal single-backscattering model. The results show that the mean scattering coefficient value for colorectal polyps is 1.91 mm−1(std: ±0.54 mm−1), which is between the values for normal and malignant tissues. In addition, we studied the difference between adenomatous polyps (n=15) and inflammatory polyps (n=2) quantitatively and found that the adenomatous tissues had lower scattering coefficients than the inflammatory ones. The quantitative measurements confirmed that OCT can be used in primary diagnosis to compensate for the deficiencies in methods of pathological diagnosis, with a great potential for early diagnosis of tissues.

scholarly journals Flexible Computationally Efficient Platform for Simulating Scan Formation in Optical Coherence Tomography with Accounting for Arbitrary Motions of Scatterers

2021 ◽  
Vol 7 (1) ◽  
pp. 010304
Author(s):  
Alexey Zykov ◽  
Alexander Matveyev ◽  
Lev Matveev ◽  
Alexander Sovetsky ◽  
Vladimir Zaitsev
Keyword(s):  
Optical Coherence Tomography ◽  
Numerical Simulations ◽  
Biological Tissues ◽  
Realistic Model ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Computationally Efficient ◽  
Proposed Model ◽  
Speckle Patterns ◽  
Rotational Motions

A computationally efficient and fairly realistic model of OCT-scan formation in spectral-domain optical coherence tomography is described. The model is based on the approximation of discrete scatterers and ballistic character of scattering, these approximations being widely used in literature. An important feature of the model is its ability to easily account for arbitrary scatterer motions and computationally efficiently generate large sequences of OCT scans for gradually varying configurations of scatterers. This makes the proposed simulation platform very convenient for studies related to the development of angiographic processing of OCT scans for visualization of microcirculation of blood, as well as for studies of decorrelation of speckle patterns in OCT scans due to random (Brownian type) motions of scatterers. Examples demonstrating utilization of the proposed model for generation OCT scans imitating perfused vessels in biological tissues, as well as evolution of speckles in OCT scans due to random translational and rotational motions of localized (but not-point-like) scatterers are given. To the best of our knowledge, such numerical simulations of large series of OCT scans in the presence of various types of motion of scatterers have not been demonstrated before.

scholarly journals Corneal and Epithelial Thickness Mapping: Comparison of Swept-Source- and Spectral-Domain-Optical Coherence Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Cristina Georgeon ◽  
Ilanite Marciano ◽  
Roxane Cuyaubère ◽  
Otman Sandali ◽  
Nacim Bouheraoua ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Spectral Domain ◽  
Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Swept Source ◽  
Epithelial Thickness ◽  
Spectral Domain Oct ◽  
Anterior Lamellar Keratoplasty ◽  
Sd Oct

Objective. To compare the results and repeatability of the corneal thickness (CT) and epithelial thickness (ET) maps provided by Swept-Source-Optical Coherence Tomography with those of Spectral-Domain-OCT in normal eyes. Methods. 30 normal eyes of 30 patients were assessed by 3 trained operators with SS-OCT and SD-OCT. Results. The central and minimum ET obtained with both devices were correlated: central ET, r = 0.86, p < 0.05 ; minimum ET, r = 0.72, p < 0.05 . Compared with SD-OCT, SS-OCT tended to underestimate these figures by 1.4 and 1.9 μm on average. The central and minimum CT obtained with both devices were strongly correlated: central CT, r = 0.994, p < 0.05 ; minimum CT, r = 0.995, p < 0.05 . SS-OCT tended to overestimate these figures by 11 and 14 μm on average. Repeatability was good for both devices with a mean coefficient of variation of measurements <6% for ET and <2% for CT. Interoperator variability (standard deviation and COV) was significantly higher for SS-OCT than for SD-OCT for all local epithelial thicknesses and significantly lower for the central CT and several local corneal thicknesses, whereas no significant differences between both technologies were found for the central and minimum ET and the minimum CT. Conclusion. SS-OCT and SD-OCT provide reproducible measurements of CT and ET in normal corneas with a strong correlation between both technologies. However, both technologies are not interchangeable when the main thickness parameters (i.e., central and minimum CT and minimum ET) are used for diagnosing early keratoconus or calculating the expected residual stromal bed thickness before corneal refractive surgery or anterior lamellar keratoplasty.

scholarly journals Integrating photoacoustic microscopy, optical coherence tomography, OCT angiography, and fluorescence microscopy for multimodal imaging

2020 ◽  
Vol 245 (4) ◽  
pp. 342-347 ◽  
Author(s):  
Arash Dadkhah ◽  
Shuliang Jiao
Keyword(s):  
Optical Coherence Tomography ◽  
Fluorescence Microscopy ◽  
Multimodal Imaging ◽  
Imaging System ◽  
Optical Resolution ◽  
Biological Tissues ◽  
Large Field ◽  
Optical Coherence ◽  
Photoacoustic Microscopy

We have developed a multimodal imaging system, which integrated optical resolution photoacoustic microscopy, optical coherence tomography, optical coherence tomography angiography, and confocal fluorescence microscopy in one platform. The system is able to image complementary features of a biological sample by combining different contrast mechanisms. We achieved fast imaging and large field of view by combining optical scanning with mechanical scanning, similar to our previous publication. We have demonstrated the capability of the multimodal imaging system by imaging a mouse ear in vivo. Impact statement Photoacoustic microscopy-based multimodal imaging technology can provide high-resolution complementary information for biological tissues in vivo. It will potentially bring significant impact on the research and diagnosis of diseases by providing combined structural and functional information.

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