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 Scattering Coefficients of Mice Organs Categorized Pathologically by Spectral Domain Optical Coherence Tomography

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Q. Q. Zhang ◽  
X. J. Wu ◽  
C. Wang ◽  
S. W. Zhu ◽  
Y. L. Wang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Curve Fitting ◽  
Spectral Domain ◽  
Scattering Coefficient ◽  
Optical Coherence ◽  
Tissue Specific ◽  
Tissue Density ◽  
Tissue Diagnosis ◽  
Scattering Coefficients

Differences in tissue density cause a variety of scattering coefficients. To quantify optical coherence tomography (OCT) images for diagnosis, the tissue's scattering coefficient is estimated by curve fitting the OCT signals to a confocal single backscattering mode. The results from a group of 30 mice show that the scattering coefficients of bone, skin, liver, brain, testis, and spleen can be categorized into three groups: a scattering coefficient between 1.947 and 2.134 mm−1: bone and skin; a scattering coefficient between 1.303 and 1.461 mm−1: liver and brain; a scattering coefficient between 0.523 and 0.634 mm−1: testis and spleen. The results indicate that the scattering coefficient is tissue specific and could be used in tissue diagnosis.

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.

CHARACTERIZATION OF VITILIGO BY IN VIVO SCATTERING COEFFICIENT OF HUMAN SKIN

2011 ◽  
Vol 04 (01) ◽  
pp. 67-72 ◽  
Author(s):  
WANRONG GAO ◽  
PENG LEE ◽  
XIANLING ZHANG
Keyword(s):  
Optical Coherence Tomography ◽  
Human Skin ◽  
Experimental Results ◽  
Scattering Coefficient ◽  
Optical Coherence ◽  
Scattering Coefficients ◽  
Significant Difference

Scattering coefficients of human skin in vivo with and without vitiligo were measured with optical coherence tomography (OCT). The experimental results show that there exist significant difference between the scattering coefficient of the epidermis of in vivo human skin with and without vitiligo disease. The results may be helpful for quantitatively diagnosing or evaluating the treatment of the disease.

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.

Imaging of the Retinal Nerve Fibre Layer with Spectral-domain Optical Coherence Tomography in Patients with Glaucoma

2010 ◽  
Vol 04 (01) ◽  
pp. 17
Author(s):  
Antonio Ferreras ◽  
Luis E Pablo ◽  
◽  
Keyword(s):  
Optical Coherence Tomography ◽  
Nerve Fibre ◽  
Time Domain ◽  
Retinal Nerve Fibre Layer ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Spectral Domain Oct ◽  
Fibre Layer ◽  
Diagnostic Potential ◽  
Nerve Fibre Layer

Evaluation of the retinal nerve fibre layer (RNFL) is key to diagnosing and monitoring changes in glaucoma. Optical coherence tomography (OCT) is a non-invasive, objective, quantitative method that provides realtimein vivoimages of the retina. The new spectral-domain OCTs have increased resolution and acquisition speed compared with earlier time-domain OCTs, enabling the generation of highly detailed 3D images. Axial resolution has also been improved from 10 to 3–5μm. Thus, spectral-domain OCT is a promising new clinical tool for evaluating the RNFL in glaucoma and other retinal diseases. Recent studies report that spectral-domain OCT provides peri-papillary RNFL measurements with excellent repeatability and reproducibility. The reduced variability compared with time-domain OCT may improve detection of disease progression in glaucoma patients. In cross-sectional studies, most authors suggest that the two OCT systems have similar diagnostic potential to discriminate between healthy and glaucoma patients. Nevertheless, the Cirrus HD-OCT (spectral-domain) tends to yield a slightly higher sensitivity at fixed specificities than the Stratus OCT (time-domain) for glaucoma diagnosis. In healthy subjects and patients with glaucoma, RNFL thickness measurements acquired with the two OCT systems correlated well, but their values cannot be used interchangeably.

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