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Sample records for coherence tomography ultrasound

  1. Spatial smoothing coherence factor for ultrasound computed tomography

    Science.gov (United States)

    Lou, Cuijuan; Xu, Mengling; Ding, Mingyue; Yuchi, Ming

    2016-04-01

    In recent years, many research studies have been carried out on ultrasound computed tomography (USCT) for its application prospect in early diagnosis of breast cancer. This paper applies four kinds of coherence-factor-like beamforming methods to improve the image quality of synthetic aperture focusing method for USCT, including the coherence-factor (CF), the phase coherence factor (PCF), the sign coherence factor (SCF) and the spatial smoothing coherence factor (SSCF) (proposed in our previous work). The performance of these methods was tested with simulated raw data which were generated by the ultrasound simulation software PZFlex 2014. The simulated phantom was set to be water of 4cm diameter with three nylon objects of different diameters inside. The ring-type transducer had 72 elements with a center frequency of 1MHz. The results show that all the methods can reveal the biggest nylon circle with the radius of 2.5mm. SSCF gets the highest SNR among the proposed methods and provides a more homogenous background. None of these methods can reveal the two smaller nylon circles with the radius of 0.75mm and 0.25mm. This may be due to the small number of elements.

  2. [Dome-shaped macula: appearance on ultrasound and optical coherence tomography].

    Science.gov (United States)

    Chéour, M; Ben Aleya, N; Brour, J; Falfoul, Y; Agrebi, S; Skhiri, M; Kraïem, A

    2013-10-01

    The purpose of our work is to demonstrate the role of optical coherence tomography and ocular ultrasound in the diagnosis of the dome-shaped macula in high myopia. We report the case of a patient with high myopia who presented with a decrease in visual acuity and metamorphopsia in the left eye. She underwent visual acuity measurement, biomicroscopic examination and measurement of axial length. B-mode ultrasound and optical coherence tomography showed a projection of the macula in the convexity of the myopic staphyloma confirming the diagnosis of dome-shaped macula. Dome-shaped macula is a recently discovered entity, which may be responsible for a decrease in visual acuity in patients with high myopic posterior staphyloma. Ultrasound and optical coherence tomography are very helpful in making the diagnosis. Copyright © 2013. Published by Elsevier Masson SAS.

  3. Currently available methodologies for the processing of intravascular ultrasound and optical coherence tomography images.

    Science.gov (United States)

    Athanasiou, Lambros; Sakellarios, Antonis I; Bourantas, Christos V; Tsirka, Georgia; Siogkas, Panagiotis; Exarchos, Themis P; Naka, Katerina K; Michalis, Lampros K; Fotiadis, Dimitrios I

    2014-07-01

    Optical coherence tomography and intravascular ultrasound are the most widely used methodologies in clinical practice as they provide high resolution cross-sectional images that allow comprehensive visualization of the lumen and plaque morphology. Several methods have been developed in recent years to process the output of these imaging modalities, which allow fast, reliable and reproducible detection of the luminal borders and characterization of plaque composition. These methods have proven useful in the study of the atherosclerotic process as they have facilitated analysis of a vast amount of data. This review presents currently available intravascular ultrasound and optical coherence tomography processing methodologies for segmenting and characterizing the plaque area, highlighting their advantages and disadvantages, and discusses the future trends in intravascular imaging.

  4. Offline fusion of co-registered intravascular ultrasound and frequency domain optical coherence tomography images for the analysis of human atherosclerotic plaques

    DEFF Research Database (Denmark)

    Räber, Lorenz; Heo, Jung Ho; Radu, Maria D

    2012-01-01

    To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images.......To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images....

  5. Perspectives on Imaging the Left Main Coronary Artery Using Intravascular Ultrasound and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Harry C Lowe

    2015-01-01

    Full Text Available Percutaneous Coronary Intervention (PCI for significant left main coronary artery (LMCA stenosis is increasingly being viewed as a viable alternative to Coronary Artery Bypass Grafting (CABG (1. This is leading to an expectation of increasing numbers of such procedures, with a consequent focus on both the ability to image both lesion severity, and assess more accurately the results of PCI. While there have been advances in physiologic assessment of left main severity using fractional flow reserve (FFR, imaging of the LMCA using Intravascular Ultrasound (IVUS and more recently Optical Coherence Tomography (OCT has the specific advantage of being able to provide detailed anatomical information both pre and post PCI, such that it is timely to review briefly the current status of these two imaging technologies in the context of LMCA intervention.

  6. Head to head comparison of optical coherence tomography, intravascular ultrasound echogenicity and virtual histology for the detection of changes in polymeric struts over time

    DEFF Research Database (Denmark)

    Brugaletta, Salvatore; Gomez-Lara, Josep; Bruining, Nico

    2012-01-01

    To analyse and to compare the changes in the various optical coherence tomography (OCT), echogenicity and intravascular ultrasound virtual histology (VH) of the everolimus-eluting bioresorbable scaffold (ABSORB) degradation parameters during the first 12 months after ABSORB implantation. In the A......To analyse and to compare the changes in the various optical coherence tomography (OCT), echogenicity and intravascular ultrasound virtual histology (VH) of the everolimus-eluting bioresorbable scaffold (ABSORB) degradation parameters during the first 12 months after ABSORB implantation...

  7. Macular hole: 10 and 20-MHz ultrasound and spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Juliana Mantovani Bottós

    2012-12-01

    Full Text Available PURPOSE: Optical coherence tomography (OCT is valuable for macula evaluation. However, as this technique relies on light energy it cannot be performed in the presence of opaque media. In such cases, the ultrasound (US may predict some macular features. The aim of this study was to characterize images obtained by ultrasound with 10 and 20-MHz transducers comparing to OCT, as well as to analyze the relationship between the vitreous and retina in eyes with macular hole (MH. METHODS: 29 eyes of 22 patients with biomicroscopic evidence of MH at different stages were included. All patients were evaluated using ultrasonography with 10 and 20-MHz transducers and OCT. RESULTS: OCT identified signs of MH in 25 of 29 eyes. The remaining 4 cases not identified by US were pseudoholes caused by epiretinal membranes. In MH stages I (2 eyes and II (1 eye, both transducers were not useful to analyze the macular thickening, but suggestive findings as macular irregularity, operculum or partial posterior vitreous detachment (PVD were highlighted. In stages III (14 eyes and IV (5 eyes, both transducers identified the double hump irregularity and thickening. US could measure the macular thickness and other suggestive findings for MH: operculum, vitreomacular traction and partial or complete PVD. In cases of pseudoholes, US identified irregularities macular contour and a discrete depression. CONCLUSION: 10-MHz US was useful for an overall assessment of the vitreous body as well as its relationship to the retina. The 20-MHz transducer allowed valuable information on the vitreomacular interface and macular contour. OCT provides superior quality for fine morphological study of macular area, except in cases of opaque media. In these cases, and even if OCT is not available, the combined US study is able to provide a valid evaluation of the macular area improving therapeutic approach.

  8. Exploratory Analysis of Carbon Dioxide Levels, Ultrasound and Optical Coherence Tomography Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Coble, C.; Mason, S.; Young, M.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Patel, N.; Gibson, C.; Alexander, D.; hide

    2017-01-01

    Carbon dioxide (CO2) levels on board the International Space Station (ISS) have typically averaged 2.3 to 5.3 mmHg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow (CBF). Increased CBF leads to elevated intracranial pressure (ICP), a factor leading to visual disturbances, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve and optical coherence tomography (OCT) provide surrogate measurements of ICP; in-flight measurements of both were implemented as enhanced screening tools for the Visual Impairment/Intracranial Pressure (VIIP) syndrome. This analysis examines the relationships between ambient CO2 levels on ISS, ultrasound and OCT measures of the eye in an effort to understand how CO2 may possibly be associated with VIIP and to inform future analysis of in-flight VIIP data.

  9. Optical Coherence Tomography Analysis of Attenuated Plaques Detected by Intravascular Ultrasound in Patients with Acute Coronary Syndromes

    Directory of Open Access Journals (Sweden)

    Takashi Kubo

    2011-01-01

    Full Text Available Background. Recent intravascular ultrasound (IVUS studies have demonstrated that hypoechoic plaque with deep ultrasound attenuation despite absence of bright calcium is common in acute coronary syndrome. Such “attenuated plaque” may be an IVUS characteristic of unstable lesion. Methods. We used optical coherence tomography (OCT in 104 patients with unstable angina to compare lesion characteristics between IVUS-detected attenuated plaque and nonattenuated plaque. Results. IVUS-detected attenuated plaque was observed in 41 (39% patients. OCT-detected lipidic plaque (88% versus 49%, <0.001, thin-cap fibroatheroma (48% versus 16%, <0.001, plaque rupture (44% versus 11%, <0.001, and intracoronary thrombus (54% versus 17%, <0.001 were more often seen in IVUS-detected attenuated plaques compared with nonattenuated plaques. Conclusions. IVUS-detected attenuated plaque has many characteristics of unstable coronary lesion. The presence of attended plaque might be an important marker of lesion instability.

  10. Comparison of immersion ultrasonography, ultrasound biomicroscopy and anterior segment optical coherence tomography in the evaluation of traumatic phacoceles

    Directory of Open Access Journals (Sweden)

    Harikrishna Vodapalli

    2012-01-01

    Full Text Available Blunt ocular trauma in the elderly can result in anterior dislocation of the crystalline lens into the subconjunctival space (phacocele. Although rare, this presentation can be missed, especially if the patient presents several days after the injury and if the lid is not everted on examination. While a careful clinical examination is adequate in the diagnosis, imaging techniques can be put to use for the accurate location of the associated sclera rupture. We report three cases of post-traumatic phacocele wherein ultrasound biomicroscopy (UBM was compared to the anterior segment optical coherence tomography (AS-OCT and B-scan ultrasonography (B-scan, in order to establish the best imaging tool for this condition. We concluded, based on image quality, that UBM could be the imaging modality of choice to aid in the diagnosis of phacocele.

  11. Intracoronary optical coherence tomography

    DEFF Research Database (Denmark)

    Tenekecioglu, Erhan; Albuquerque, Felipe N; Sotomi, Yohei

    2017-01-01

    By providing valuable information about the coronary artery wall and lumen, intravascular imaging may aid in optimizing interventional procedure results and thereby could improve clinical outcomes following percutaneous coronary intervention (PCI). Intravascular optical coherence tomography (OCT...

  12. Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Pier Alberto Testoni

    2007-01-01

    Full Text Available Optical coherence tomography (OCT is an optical imaging modality that performs high-resolution, cross-sectional, subsurface tomographic imaging of the microstructure of tissues. The physical principle of OCT is similar to that of B-mode ultrasound imaging, except that it uses infrared light waves rather than acoustic waves. The in vivo resolution is 10–25 times better (about 10 µm than with high-frequency ultrasound imaging, but the depth of penetration is limited to 1–3 mm, depending on tissue structure, depth of focus of the probe used, and pressure applied to the tissue surface. In the last decade, OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice, including the gastrointestinal tract and pancreatico-biliary ductal system. OCT imaging from the gastrointestinal tract can be done in humans by using narrow-diameter, catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope, for investigating the epithelial structure of the gastrointestinal tract, or a side-view endoscope, inside a standard transparent ERCP (endoscopic retrograde cholangiopancreatography catheter, for investigating the pancreatico-biliary ductal system. The esophagus and esophagogastric junction have been the most widely investigated organs so far; more recently, duodenum, colon, and the pancreatico-biliary ductal system have also been extensively investigated. OCT imaging of the gastrointestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa, lamina propria, muscularis mucosae, and part of the submucosa. The technique may therefore be used to identify preneoplastic conditions of the gastrointestinal tract, such as Barrett's epithelium and dysplasia, and evaluate the depth of penetration of early-stage neoplastic lesions. OCT imaging

  13. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging

    Science.gov (United States)

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  14. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Themstrup, Lotte; Banzhaf, Christina

    2014-01-01

    Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described as the o......Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described...

  15. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Fercher, A.F.; Andersen, Peter E.

    2017-01-01

    Optical coherence tomography (OCT) is a technique that is used to peer inside a body noninvasively. Tissue structure defined by tissue absorption and scattering coefficients, and the speed of blood flow, are derived from the characteristics of light remitted by the body. Singly backscattered light...... detected by partial coherence interferometry (PCI) is used to synthesize the tomographic image coded in false colors. A prerequisite of this technique is a low time-coherent but high space-coherent light source, for example, a superluminescent diode or a supercontinuum source. Alternatively, the imaging...... technique can be realized by using ultrafast wavelength scanning light sources. For tissue imaging, the light source wavelengths are restricted to the red and near-infrared (NIR) region from about 600 to 1300 nm, the so-called therapeutic window, where absorption (μa ≈ 0.01 mm−1) is small enough. Transverse...

  16. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography.

    Science.gov (United States)

    Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

    2014-06-01

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography

    International Nuclear Information System (INIS)

    Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

    2014-01-01

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator’s identification of landmarks to establish the image synchronization

  18. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, Stéphane, E-mail: sgcarlier@hotmail.com [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Didday, Rich [INDEC Medical Systems Inc., Santa Clara, CA (United States); Slots, Tristan [Pie Medical Imaging BV, Maastricht (Netherlands); Kayaert, Peter; Sonck, Jeroen [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); El-Mourad, Mike; Preumont, Nicolas [Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Schoors, Dany; Van Camp, Guy [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium)

    2014-06-15

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator’s identification of landmarks to establish the image synchronization.

  19. Optical coherence tomography in dermatology

    Science.gov (United States)

    Sattler, Elke; Kästle, Raphaela; Welzel, Julia

    2013-06-01

    Optical coherence tomography (OCT) is a noninvasive diagnostic method that offers a view into the superficial layers of the skin in vivo in real-time. An infrared broadband light source allows the investigation of skin architecture and changes up to a depth of 1 to 2 mm with a resolution between 15 and 3 μm, depending on the system used. Thus OCT enables evaluation of skin lesions, especially nonmelanoma skin cancers and inflammatory diseases, quantification of skin changes, visualization of parasitic infestations, and examination of other indications such as the investigation of nails. OCT provides a quick and useful diagnostic imaging technique for a number of clinical questions and is a valuable addition or complement to other noninvasive imaging tools such as dermoscopy, high-frequency ultrasound, and confocal laser scan microscopy.

  20. In vitro study of the effects of ultrasound-mediated glycerol on optical attenuation of human normal and cancerous esophageal tissues with optical coherence tomography

    International Nuclear Information System (INIS)

    Zhang, Y Q; Wei, H J; Guo, Z Y; Gu, H M; Guo, X; Zhu, Z G; Yang, H Q; Xie, S S

    2013-01-01

    Previous studies from our group have demonstrated that glucose solution can induce optical clearing enhancement of esophageal tissues with optical coherence tomography (OCT). The aims of this study were to evaluate the optical clearing effects of ultrasound-mediated optical clearing agents (OCAs) and to find more effective methods to distinguish human normal esophageal tissues (NE) and cancerous esophageal tissues (CE). Here we used the OCT technique to investigate the optical attenuation of NE and CE in vitro after treatment with 30% glycerol alone and glycerol combined with ultrasound, respectively. Experimental results showed that the averaged attenuation coefficient of CE was significantly larger than that of NE. The maximal decreases of averaged attenuation coefficients of NE and CE were approximately 48.7% and 36.2% after treatment with 30% glycerol alone, and they were significantly lower than those treated with 30% glycerol and ultrasound (57.5% in NE and 44.8% in CE). Moreover, after treatment with 30% glycerol alone, the averaged attenuation coefficients of NE and CE reached their minima in about 80 min and 65 min, respectively. The times were much shorter in NE and CE after treatment with glycerol with ultrasound, being about 62 min and 50 min, respectively. The results suggest that there is a significant difference in the optical properties of NE and CE, and that OCT with an ultrasound–OCAs combination has the ability to distinguish CE from NE. (paper)

  1. Optical coherence tomography: Technique and applications

    DEFF Research Database (Denmark)

    Thomsen, Jakob Borup; Sander, Birgit; Mogensen, Mette

    2009-01-01

    Optical coherence tomography (OCT) is a noninvasive optical imaging modality providing real-time video rate images in two and three dimensions of biological tissues with micrometer resolution. OCT fills the gap between ultrasound and confocal microscopy, since it has a higher resolution than...... of retinal diseases. The potential of OCT in many other applications is currently being explored, such as in developmental biology, skin cancer diagnostics, vulnerable plaque detection in cardiology, esophageal diagnostics and a number of other applications within oncology....

  2. Comparison of Central Corneal Thickness Measured by Standard Ultrasound Pachymetry, Corneal Topography, Tono-Pachymetry and Anterior Segment Optical Coherence Tomography.

    Science.gov (United States)

    González-Pérez, Javier; Queiruga Piñeiro, Juan; Sánchez García, Ángelx; González Méijome, José Manuel

    2018-04-10

    To compare central corneal thickness (CCT) measured by standard ultrasound pachymetry (USP), and three non-contact devices in healthy eyes. A cross-sectional study of CCT measurement in 52 eyes of 52 healthy volunteers was done by a single examiner at Ocular Surface and Contact Lens Laboratory. Three consecutive measurements were done by standard USP, non-contact tono-pachymeter, Pentacam corneal topographer, and Anterior Segment Optical Coherence Tomography (AS-OCT). The mean values were used for assessment. The results were compared using multivariate ANOVA, linear regression, and Pearson correlation. Agreement among the devices was analyzed using mean differences and Bland-Altman analysis with 95% limits of agreement (LoA). Finally, reliability was analyzed using intraclass correlation coefficient (ICC). Mean CCT by ultrasound pachymeter, tono-pachymeter, corneal topographer and AS-OCT were 558.9 ± 31.2 µm, 525.8 ± 43.1 µm, 550.4 ± 30.5 µm, and 545.9 ± 30.5 µm respectively. There was a significant positive correlation between AS-OCT and USP (Pearson correlation = 0.957, p device, and USP. Mean CCT among USP, Pentacam and AS-OCT were comparable and had significant linear correlations. In clinical practice, these three modalities could be interchangeable in healthy patients.

  3. Optical coherence tomography of the newborn airway.

    Science.gov (United States)

    Ridgway, James M; Su, Jianping; Wright, Ryan; Guo, Shuguang; Kim, David C; Barretto, Roberto; Ahuja, Gurpreet; Sepehr, Ali; Perez, Jorge; Sills, Jack H; Chen, Zhongping; Wong, Brian J F

    2008-05-01

    Acquired subglottic stenosis in a newborn is often associated with prolonged endotracheal intubation. This condition is generally diagnosed during operative endoscopy after airway injury has occurred. Unfortunately, endoscopy is unable to characterize the submucosal changes observed in such airway injuries. Other modalities, such as magnetic resonance imaging, computed tomography, and ultrasound, do not possess the necessary level of resolution to differentiate scar, neocartilage, and edema. Optical coherence tomography (OCT) is an imaging modality that produces high-resolution, cross-sectional images of living tissue (8 to 20 microm). We examined the ability of this noninvasive technique to characterize the newborn airway in a prospective clinical trial. Twelve newborn patients who required ventilatory support underwent OCT airway imaging. Comparative analysis of intubated and non-intubated states was performed. Imaging of the supraglottis, glottis, subglottis, and trachea was performed in 12 patients, revealing unique tissue characteristics as related to turbidity, signal backscattering, and architecture. Multiple structures were identified, including the vocal folds, cricoid cartilage, tracheal rings, ducts, glands, and vessels. Optical coherence tomography clearly identifies in vivo tissue layers and regional architecture while offering detailed information concerning tissue microstructures. The diagnostic potential of this technology makes OCT a promising modality in the study and surveillance of the neonatal airway.

  4. Imaging granulomatous lesions with optical coherence tomography

    DEFF Research Database (Denmark)

    Banzhaf, Christina; Jemec, Gregor B E

    2012-01-01

    To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors.......To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors....

  5. Extracting subsurface fingerprints using optical coherence tomography

    CSIR Research Space (South Africa)

    Akhoury, SS

    2015-02-01

    Full Text Available Subsurface Fingerprints using Optical Coherence Tomography Sharat Saurabh Akhoury, Luke Nicholas Darlow Modelling and Digital Science, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract Physiologists have found... approach to extract the subsurface fingerprint representation using a high-resolution imaging technology known as Optical Coherence Tomography (OCT). ...

  6. Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial.

    Science.gov (United States)

    Ali, Ziad A; Maehara, Akiko; Généreux, Philippe; Shlofmitz, Richard A; Fabbiocchi, Franco; Nazif, Tamim M; Guagliumi, Giulio; Meraj, Perwaiz M; Alfonso, Fernando; Samady, Habib; Akasaka, Takashi; Carlson, Eric B; Leesar, Massoud A; Matsumura, Mitsuaki; Ozan, Melek Ozgu; Mintz, Gary S; Ben-Yehuda, Ori; Stone, Gregg W

    2016-11-26

    Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25-3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural

  7. Polarization sensitive optical coherence tomography in dentistry

    International Nuclear Information System (INIS)

    Dichtl, S.

    1998-01-01

    Optical coherence tomography (OCT) is a noninvasive and noncontact technique for obtaining cross-sectional images of biologic structure, which was initially introduced to depict the transparent tissue of the eye. It employs the partial coherence properties of a light source to image structures with high resolution (< 20 (m). Recently, this technique has also been applied in turbid media. This tomographic imaging is analogous to conventional ultrasound B mode imaging, except that OCT measures the intensity of backreflected infrared light rather than acoustical waves. First applications, of OCT in dentistry for diagnosing periodontal disease have been reported by Colston et al. presenting in vitro OCT images of the dental and periodontal tissues of porcine premolar teeth. In this work, the feasibility of polarisation sensitive OCT for dental material is suggested. In contrast with conventional OCT, where the magnitude of backscattered light as a function of depth is imaged, backscattered light is used to image the magnitude of the birefringence in the sample as a function of depth. Partial loss of birefringence is known to be an early indication of incipient caries or tissue thermal damage. Applying this technique for caries diagnosis or guidance regarding optimal dosimetry for thermally mediated laser therapeutic procedures, polarisation sensitive OCT would represent a promising new technology for dentistry. (author)

  8. Optical Coherence Tomography of the Aging Kidney.

    Science.gov (United States)

    Andrews, Peter M; Wang, Hsing-Wen; Guo, Hengchang; Anderson, Erik; Falola, Reuben; Chen, Yu

    2016-12-01

    The aging kidney exhibits a progressive decline in renal function with characteristic histopathologic changes and is a risk factor for renal transplant. However, the degree to which the kidney exhibits this decline depends on several factors that vary from one individual to the next. Optical coherence tomography is an evolving noninvasive imaging technology that has recently been used to evaluate acute tubular necrosis of living-human donor kidneys before their transplant. With the increasing use of kidneys from older individuals, it is important to determine whether optical coherence tomography also can distinguish the histopathology associated with aging. In this investigation, we used Munich-Wistar rats to evaluate the ability of optical coherence tomography to detect histopathologic changes associated with aging. Optical coherence tomography observations were correlated with renal function and conventional light microscopic evaluation of these same kidneys. With the onset of severe proteinuria at 10 to 12 months of age, optical coherence tomography revealed tubular necrosis/atrophy, interstitial fibrosis, tubular dilation, and glomerulosclerosis. With a further deterioration in kidney function at 16 to 18 months of age (as indicated by rising creatinine levels), optical coherence tomography revealed more extensive interstitial fibrosis and tubular atrophy, increased tubular dilation with cyst formation and more sclerotic glomeruli. The foregoing observations suggest that optical coherence tomography can be used to detect the histopathology of progressive nephropathy associated with aging.

  9. Diffusion tensor optical coherence tomography

    Science.gov (United States)

    Marks, Daniel L.; Blackmon, Richard L.; Oldenburg, Amy L.

    2018-01-01

    In situ measurements of diffusive particle transport provide insight into tissue architecture, drug delivery, and cellular function. Analogous to diffusion-tensor magnetic resonance imaging (DT-MRI), where the anisotropic diffusion of water molecules is mapped on the millimeter scale to elucidate the fibrous structure of tissue, here we propose diffusion-tensor optical coherence tomography (DT-OCT) for measuring directional diffusivity and flow of optically scattering particles within tissue. Because DT-OCT is sensitive to the sub-resolution motion of Brownian particles as they are constrained by tissue macromolecules, it has the potential to quantify nanoporous anisotropic tissue structure at micrometer resolution as relevant to extracellular matrices, neurons, and capillaries. Here we derive the principles of DT-OCT, relating the detected optical signal from a minimum of six probe beams with the six unique diffusion tensor and three flow vector components. The optimal geometry of the probe beams is determined given a finite numerical aperture, and a high-speed hardware implementation is proposed. Finally, Monte Carlo simulations are employed to assess the ability of the proposed DT-OCT system to quantify anisotropic diffusion of nanoparticles in a collagen matrix, an extracellular constituent that is known to become highly aligned during tumor development.

  10. The potential of high intensity focused ultrasound (HIFU) combine phase-sensitive optical coherence tomography (PhS-OCT) for diseases diagnosis, treatment and monitoring

    Science.gov (United States)

    Zhou, Kanheng; Wang, Yan; Feng, Kairui; Li, Chunhui; Huang, Zhihong

    2018-02-01

    HIFU is a truly noninvasive, acoustic therapeutic technique that utilizes high intensity acoustic field in the focus to kill the targeted tissue for disease treatment purpose. The mechanical properties of targeted tissue changes before and after treatment, and this change can be accurately detected by shear wave elastography. Hence, shear wave elastography is usually used for monitoring HIFU treatment asynchronously. To improve the low spatial resolution in ultrasound shear wave elastography, and to perform diseases diagnosis, treatment and monitoring in the same system, a new setup that combines HIFU and PhS-OCT system was proposed in this study. This proposed setup could do 1) HIFU treatment when the transducer works at high energy level, 2) ultrasound induced shear wave optical coherence elastography for HIFU treatment asynchronous monitoring when the transducer works at low energy level. Ex-vivo bovine liver tissue was treated at the same energy level for different time (0s, 1s, 5s, 9s) in this research. Elastography was performed on the lesion area of the sample after HIFU treatment, and the elastogram was reconstructed by the time of flight time method. The elastogram results clearly show the boundary of HIFU lesion area and surrounding normal tissue, even for 1s treatment time. And the average elasticity of the lesion grows linearly as the treatment time increases. Combined with OCT needle probe, the proposed method has a large potential not only to be used for superficial diseases treatment, but also to be used for high-precision-demanded diseases treatment, e.g. nervous disease treatment.

  11. Optical Coherence Tomography for the Assessment of Coronary Atherosclerosis and Vessel Response after Stent Implantation

    NARCIS (Netherlands)

    N. Gonzalo (Nieves)

    2010-01-01

    textabstractOptical Coherence Tomography (OCT) is a light-based imaging modality that can provide in vivo high-resolution images of the coronary artery with a level of resolution (axial 10-20 µm) ten times higher than intravascular ultrasound. The technique, uses low-coherent near infrarred light

  12. Optical coherence tomography technology and applications

    CERN Document Server

    Fujimoto, James

    2015-01-01

    Optical coherence tomography (OCT) is the optical analog of ultrasound imaging and is a powerful imaging technique that enables non-invasive, in vivo, high resolution, cross-sectional imaging in biological tissue.  Between 30 to 40 Million OCT imaging procedures are performed per year in ophthalmology.  The overall market is estimated at more than 0.5 Billion USD.  A new generation OCT technology was developed, dramatically increasing resolution and speed, achieving in vivo optical biopsy, i.e. the visualization of tissue architectural morphology in situ and in real time.  Functional extensions of OCT technology enable non-invasive, depth resolved functional assessment and imaging of tissue.  The book introduces OCT technology and applications not only from an optical and technological viewpoint, but also from the biomedical and clinical perspective. This second edition is widely extended and covers significantly more topics then the first edition of this book. The chapters are written leading intern...

  13. Optical coherence tomography in gastroenterology: a review and future outlook

    Science.gov (United States)

    Tsai, Tsung-Han; Leggett, Cadman L.; Trindade, Arvind J.; Sethi, Amrita; Swager, Anne-Fré; Joshi, Virendra; Bergman, Jacques J.; Mashimo, Hiroshi; Nishioka, Norman S.; Namati, Eman

    2017-12-01

    Optical coherence tomography (OCT) is an imaging technique optically analogous to ultrasound that can generate depth-resolved images with micrometer-scale resolution. Advances in fiber optics and miniaturized actuation technologies allow OCT imaging of the human body and further expand OCT utilization in applications including but not limited to cardiology and gastroenterology. This review article provides an overview of current OCT development and its clinical utility in the gastrointestinal tract, including disease detection/differentiation and endoscopic therapy guidance, as well as a discussion of its future applications.

  14. Dynamic Optical Coherence Tomography in Dermatology

    DEFF Research Database (Denmark)

    Ulrich, Martina; Themstrup, Lotte; De Carvalho, Nathalie

    2016-01-01

    Optical coherence tomography (OCT) represents a non-invasive imaging technology, which may be applied to the diagnosis of non-melanoma skin cancer and which has recently been shown to improve the diagnostic accuracy of basal cell carcinoma. Technical developments of OCT continue to expand the app...

  15. Optical coherence tomography as a diagnostic tool

    CSIR Research Space (South Africa)

    Singh, A

    2011-07-01

    Full Text Available Optical Coherence Tomography (OCT) has been used in biomedical applications as a method to non-invasively detect changes occurring in tissue such as the detection of skin cancer. The effect of skin tone on detection of skin cancer has however...

  16. Optical coherence tomography of basal cell carcinoma

    DEFF Research Database (Denmark)

    Yücel, D.; Themstrup, L.; Manfredi, Maddalena

    2016-01-01

    Background: Basal cell carcinoma (BCC) is the most prevalent malignancy in Caucasians. Optical coherence tomography (OCT) is a non-invasive optical imaging technology using the principle of interferometry. OCT has shown a great potential in diagnosing, monitoring, and follow-up of BCC. So far most...

  17. Optical coherence tomography of the rat cochlea

    NARCIS (Netherlands)

    Wong, B. J. F.; de Boer, JF; Park, B.H.; Chen, ZP; Nelson, JS

    2000-01-01

    Optical coherence tomography (OCT) was used to image the internal structure of a rat cochlea (ex vivo). Immediately following sacrifice, the temporal bone of a Sprague-Dawley rat was harvested. Axial OCT cross sectional images lover regions of interest, 1x1 mm-2x8 mm) were obtained with a spatial

  18. Optical coherence tomography in conjunction with bronchoscopy

    International Nuclear Information System (INIS)

    Rodrigues, Ascedio Jose; Takimura, Celso Kiyochi; Lemos Neto, Pedro Alves; Figueiredo, Viviane Rossi

    2012-01-01

    To evaluate the feasibility of and the potential for using optical coherence tomography in conjunction with conventional bronchoscopy in the evaluation of the airways. Methods: This was a pilot study based on an ex vivo experimental model involving three animals: one adult New Zealand rabbit and two Landrace pigs. An optical coherence tomography imaging catheter was inserted through the working channel of a flexible bronchoscope in order to reach the distal trachea of the animals. Images of the walls of the trachea were systematically taken along its entire length, from the distal to the proximal portion. Results: The imaging catheter was easily adapted to the working channel of the bronchoscope. High-resolution images of cross sections of the trachea were taken in real time, precisely delineating microstructures, such as the epithelium, submucosa, and cartilage, as well as the adventitia of the anterior and lateral tracheal walls. The corresponding layers of the epithelium, mucosa, and cartilage were clearly differentiated. The mucosa, submucosa, and trachealis muscle were clearly identified in the posterior wall. Conclusions: It is feasible to use an optical coherence tomography imaging catheter in combination with a flexible bronchoscope. Optical coherence tomography produces high resolution images that reveal the microanatomy of the trachea, including structures that are typically seen only on images produced by conventional histology. (author)

  19. Optical Coherence Tomography for Material Characterization

    NARCIS (Netherlands)

    Liu, P.

    2014-01-01

    Optical coherence tomography (OCT) is a non-invasive, contactless and high resolution imaging method, which allows the reconstruction of two or three dimensional depth-resolved images in turbid media. In the past 20 years, OCT has been extensively developed in the field of biomedical diagnostics,

  20. Optical coherence tomography in conjunction with bronchoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Ascedio Jose; Takimura, Celso Kiyochi; Lemos Neto, Pedro Alves; Figueiredo, Viviane Rossi, E-mail: ascedio@gmail.com [Servico de Endoscopia Respiratoria, Hospital das Clinicas, Universidade de Sao Paulo (FM/USP), SP (Brazil)

    2012-07-01

    To evaluate the feasibility of and the potential for using optical coherence tomography in conjunction with conventional bronchoscopy in the evaluation of the airways. Methods: This was a pilot study based on an ex vivo experimental model involving three animals: one adult New Zealand rabbit and two Landrace pigs. An optical coherence tomography imaging catheter was inserted through the working channel of a flexible bronchoscope in order to reach the distal trachea of the animals. Images of the walls of the trachea were systematically taken along its entire length, from the distal to the proximal portion. Results: The imaging catheter was easily adapted to the working channel of the bronchoscope. High-resolution images of cross sections of the trachea were taken in real time, precisely delineating microstructures, such as the epithelium, submucosa, and cartilage, as well as the adventitia of the anterior and lateral tracheal walls. The corresponding layers of the epithelium, mucosa, and cartilage were clearly differentiated. The mucosa, submucosa, and trachealis muscle were clearly identified in the posterior wall. Conclusions: It is feasible to use an optical coherence tomography imaging catheter in combination with a flexible bronchoscope. Optical coherence tomography produces high resolution images that reveal the microanatomy of the trachea, including structures that are typically seen only on images produced by conventional histology. (author)

  1. Reconstructions in ultrasound modulated optical tomography

    KAUST Repository

    Allmaras, Moritz; Bangerth, Wolfgang

    2011-01-01

    We introduce a mathematical model for ultrasound modulated optical tomography and present a simple reconstruction scheme for recovering the spatially varying optical absorption coefficient from scanning measurements with narrowly focused ultrasound signals. Computational results for this model show that the reconstruction of sharp features of the absorption coefficient is possible. A formal linearization of the model leads to an equation with a Fredholm operator, which explains the stability observed in our numerical experiments. © de Gruyter 2011.

  2. Intra-stent tissue evaluation within bare metal and drug-eluting stents > 3 years since implantation in patients with mild to moderate neointimal proliferation using optical coherence tomography and virtual histology intravascular ultrasound.

    Science.gov (United States)

    Kitabata, Hironori; Loh, Joshua P; Pendyala, Lakshmana K; Omar, Alfazir; Ota, Hideaki; Minha, Sa'ar; Magalhaes, Marco A; Torguson, Rebecca; Chen, Fang; Satler, Lowell F; Pichard, Augusto D; Waksman, Ron

    2014-04-01

    We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS). Neoatherosclerosis in neointima has been reported in BMS and in DES. Thirty patients with 36 stented lesions [BMS (n=17) or DES (n=19)] >3years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥70% diameter stenosis were excluded. The median duration from implantation was 126.0months in the BMS group and 60.0months in the DES group (p 3years to stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p=0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p=0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p=0.361) did not differ significantly. At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. High-definition optical coherence tomography

    DEFF Research Database (Denmark)

    Boone, Marc; Norrenberg, Sarah; Jemec, Gregor

    2013-01-01

    to those described for reflectance confocal microscopy but with the advantages not only to visualize individual cells up to a depth of 570 μm but also in both slice and en face mode. An adapted algorithmic method for pattern analysis of common inflammatory skin diseases could be proposed. This new......High-definition optical coherence tomography (HD-OCT) is a non-invasive technique for morphological investigation of tissue with cellular resolution filling the imaging gap between reflectance confocal microscopy and conventional optical coherence tomography. The aim of this study is first...... dermatitis. Additional studies to test the sensitivity and specificity of the proposed algorithm for pattern analysis are essential. The other categories of Ackerman's pattern recognition need to be evaluated. This study provides a set of morphological features generated by HD-OCT imaging very similar...

  4. Optical Coherence Tomography for the Assessment of Coronary Atherosclerosis and Vessel Response after Stent Implantation

    OpenAIRE

    Gonzalo, Nieves

    2010-01-01

    textabstractOptical Coherence Tomography (OCT) is a light-based imaging modality that can provide in vivo high-resolution images of the coronary artery with a level of resolution (axial 10-20 µm) ten times higher than intravascular ultrasound. The technique, uses low-coherent near infrarred light to create high-resolution cross sectional images of the vessel. The technology refinement achieved in the last years has made this imaging modality less procedurally demanding opening its possibiliti...

  5. Optical coherence tomography of dental structures

    Science.gov (United States)

    Baumgartner, Angela; Hitzenberger, Christoph K.; Dichtl, Sabine; Sattmann, Harald; Moritz, Andreas; Sperr, Wolfgang; Fercher, Adolf F.

    1998-04-01

    In the past ten years Partial Coherence Interferometry (PCI) and Optical Coherence Tomography (OCT) have been successfully developed for high precision biometry and tomography of biological tissues. OCT employs the partial coherence properties of a superluminescent diode and the Doppler principle yielding resolution and precision figures of the order of a few microns. Presently, the main application fields of this technique are biometry and imaging of ocular structures in vivo, as well as its clinical use in dermatology and endoscopic applications. This well established length measuring and imaging technique has now been applied to dentistry. First in vitro OCT images of the cemento (dentine) enamel junction of extracted sound and decayed human teeth have been recorded. These images distinguish dentine and enamel structures that are important for assessing enamel thickness and diagnosing caries. Individual optical A-Scans show that the penetration depth into enamel is considerably larger than into dentine. First polarization sensitive OCT recordings show localized changes of the polarization state of the light backscattered by dental material. Two-dimensional maps of the magnitude of the interference intensity and of the total phase difference between two orthogonal polarization states as a function of depth can reveal important structural information.

  6. Optical coherence tomography findings of quinine poisoning

    Directory of Open Access Journals (Sweden)

    John Christoforidis

    2011-01-01

    Full Text Available John Christoforidis, Robert Ricketts, Theodore Loizos, Susie ChangThe Ohio State University College of Medicine, Columbus, OH, USAPurpose: To report a case of acute quinine poisoning, document acute and chronic macular changes with optical coherence tomography imaging and fluorescein angiography (FA, and to review the literature on ocular toxicity of quinine.Methods: A 32-year-old white female presented to our Emergency Department after ingesting over 7.5 g of quinine. She underwent a complete ophthalmologic examination, fluorescein angiography, Stratus time-domain optical coherence tomography (OCT, and electroretinography at 72 hours and 15 months postingestion. Stratus time-domain and Cirrus spectral-domain OCT, fundus autofluorescence, and FA were obtained at 28 months postingestion.Results: Fluorescein angiography at 72 hours postingestion revealed normal filling times and vasculature. OCT showed marked thickening of the inner retina bilaterally. At 15 and 28 months follow-up, fundus photography and fluorescein angiography demonstrated optic nerve pallor, severely attenuated retinal vessels while OCT showed inner retinal atrophy. Fundus autofluorescence did not reveal any retinal pigmentary abnormalities.Conclusions: Quinine toxicity as seen by OCT reveals increased thickness with inner retinal hyperreflectivity acutely with development of significant retinal atrophy in the long-term. Fundus autofluorescence reveals an intact retinal pigment epithelial layer at 28 months. These findings suggest that quinine poisoning may produce a direct toxic effect on the inner retina in the acute phase resulting in long-term retinal atrophy.Keywords: retinal, optical coherence tomography, quinine toxicity 

  7. Gabor fusion master slave optical coherence tomography

    DEFF Research Database (Denmark)

    Cernat, Ramona; Bradu, Adrian; Israelsen, Niels Møller

    2017-01-01

    This paper describes the application of the Gabor filtering protocol to a Master/Slave (MS) swept source optical coherence tomography (SS)-OCT system at 1300 nm. The MS-OCT system delivers information from selected depths, a property that allows operation similar to that of a time domain OCT system......, where dynamic focusing is possible. The Gabor filtering processing following collection of multiple data from different focus positions is different from that utilized by a conventional swept source OCT system using a Fast Fourier transform (FFT) to produce an A-scan. Instead of selecting the bright...

  8. Optical biopsy of lymph node morphology using optical coherence tomography.

    Science.gov (United States)

    Luo, Wei; Nguyen, Freddy T; Zysk, Adam M; Ralston, Tyler S; Brockenbrough, John; Marks, Daniel L; Oldenburg, Amy L; Boppart, Stephen A

    2005-10-01

    Optical diagnostic imaging techniques are increasingly being used in the clinical environment, allowing for improved screening and diagnosis while minimizing the number of invasive procedures. Diffuse optical tomography, for example, is capable of whole-breast imaging and is being developed as an alternative to traditional X-ray mammography. While this may eventually be a very effective screening method, other optical techniques are better suited for imaging on the cellular and molecular scale. Optical Coherence Tomography (OCT), for instance, is capable of high-resolution cross-sectional imaging of tissue morphology. In a manner analogous to ultrasound imaging except using optics, pulses of near-infrared light are sent into the tissue while coherence-gated reflections are measured interferometrically to form a cross-sectional image of tissue. In this paper we apply OCT techniques for the high-resolution three-dimensional visualization of lymph node morphology. We present the first reported OCT images showing detailed morphological structure and corresponding histological features of lymph nodes from a carcinogen-induced rat mammary tumor model, as well as from a human lymph node containing late stage metastatic disease. The results illustrate the potential for OCT to visualize detailed lymph node structures on the scale of micrometastases and the potential for the detection of metastatic nodal disease intraoperatively.

  9. Nanoparticles displacement analysis using optical coherence tomography

    Science.gov (United States)

    StrÄ kowski, Marcin R.; Kraszewski, Maciej; StrÄ kowska, Paulina

    2016-03-01

    Optical coherence tomography (OCT) is a versatile optical method for cross-sectional and 3D imaging of biological and non-biological objects. Here we are going to present the application of polarization sensitive spectroscopic OCT system (PS-SOCT) for quantitative measurements of materials containing nanoparticles. The PS-SOCT combines the polarization sensitive analysis with time-frequency analysis. In this contribution the benefits of using the combination of timefrequency and polarization sensitive analysis are being expressed. The usefulness of PS-SOCT for nanoparticles evaluation is going to be tested on nanocomposite materials with TiO2 nanoparticles. The OCT measurements results have been compared with SEM examination of the PMMA matrix with nanoparticles. The experiment has proven that by the use of polarization sensitive and spectroscopic OCT the nanoparticles dispersion and size can be evaluated.

  10. Dynamic gonioscopy using optical coherence tomography.

    Science.gov (United States)

    Matonti, Frederic; Chazalon, Elodie; Trichet, Elodie; Khaled, El Samak; Denis, Danièle; Hoffart, Louis

    2012-01-01

    To describe the use of anterior segment optical coherence tomography (AS-OCT) in studying the dynamic changes of the anterior chamber angle by corneal indentation. In a prospective observational study, the anterior segments of 21 eyes were imaged using AS-OCT. After the initial scan, a second scan was executed on the same areas with a central corneal indentation. An evaluation of the reopening of the angle and its measurement were performed. With AS-OCT, the indirect signs were accurate enough to guide the diagnosis in all plateau iris confirmed by ultrabiomicroscopy. The angle widths were significantly increased after indentation. This method would appear to offer a convenient and rapid method of assessing the configuration of the anterior chamber; it may help during the routine clinical assessment and treatment of patients with narrow or closed angles, particularly when gonioscopy is difficult to interpret. Copyright 2012, SLACK Incorporated.

  11. Optical coherence tomography for diagnosing periodontal disease

    Science.gov (United States)

    Colston, Bill W., Jr.; Everett, Matthew J.; Da Silva, Luiz B.; Otis, Linda L.; Nathel, Howard

    1997-05-01

    We have, in this preliminary study, investigated the use of optical coherence tomography for diagnosis of periodontal disease. We took in vitro OCT images of the dental and periodontal tissues from a young pig and compared them to histological sections. These images distinguish tooth and soft tissue relationships that are important in diagnosing and assessing periodontal disease. We have imaged the attachment of gingiva to the tooth surface and located the cemento-enamel junction. This junction is an important reference point for defining attachment level in the diagnosis of periodontal disease. the boundary between enamel and dentin is also visible for most of the length of the anatomical crown, allowing quantitation of enamel thickness and character.

  12. Thermo-elastic optical coherence tomography.

    Science.gov (United States)

    Wang, Tianshi; Pfeiffer, Tom; Wu, Min; Wieser, Wolfgang; Amenta, Gaetano; Draxinger, Wolfgang; van der Steen, Antonius F W; Huber, Robert; Soest, Gijs van

    2017-09-01

    The absorption of nanosecond laser pulses induces rapid thermo-elastic deformation in tissue. A sub-micrometer scale displacement occurs within a few microseconds after the pulse arrival. In this Letter, we investigate the laser-induced thermo-elastic deformation using a 1.5 MHz phase-sensitive optical coherence tomography (OCT) system. A displacement image can be reconstructed, which enables a new modality of phase-sensitive OCT, called thermo-elastic OCT. An analysis of the results shows that the optical absorption is a dominating factor for the displacement. Thermo-elastic OCT is capable of visualizing inclusions that do not appear on the structural OCT image, providing additional tissue type information.

  13. Phase-conjugate optical coherence tomography

    International Nuclear Information System (INIS)

    Erkmen, Baris I.; Shapiro, Jeffrey H.

    2006-01-01

    Quantum optical coherence tomography (Q-OCT) offers a factor-of-2 improvement in axial resolution and the advantage of even-order dispersion cancellation when it is compared to conventional OCT (C-OCT). These features have been ascribed to the nonclassical nature of the biphoton state employed in the former, as opposed to the classical state used in the latter. Phase-conjugate OCT (PC-OCT) shows that nonclassical light is not necessary to reap Q-OCT's advantages. PC-OCT uses classical-state signal and reference beams, which have a phase-sensitive cross correlation, together with phase conjugation to achieve the axial resolution and even-order dispersion cancellation of Q-OCT with a signal-to-noise ratio that can be comparable to that of C-OCT

  14. Advanced modelling of optical coherence tomography systems

    International Nuclear Information System (INIS)

    Andersen, Peter E; Thrane, Lars; Yura, Harold T; Tycho, Andreas; Joergensen, Thomas M; Frosz, Michael H

    2004-01-01

    Analytical and numerical models for describing and understanding the light propagation in samples imaged by optical coherence tomography (OCT) systems are presented. An analytical model for calculating the OCT signal based on the extended Huygens-Fresnel principle valid both for the single and multiple scattering regimes is reviewed. An advanced Monte Carlo model for calculating the OCT signal is also reviewed, and the validity of this model is shown through a mathematical proof based on the extended Huygens-Fresnel principle. Moreover, for the first time the model is verified experimentally. From the analytical model, an algorithm for enhancing OCT images is developed; the so-called true-reflection algorithm in which the OCT signal may be corrected for the attenuation caused by scattering. For the first time, the algorithm is demonstrated by using the Monte Carlo model as a numerical tissue phantom. Such algorithm holds promise for improving OCT imagery and to extend the possibility for functional imaging

  15. Optical Coherence Tomography for Tracking Canvas Deformation

    International Nuclear Information System (INIS)

    Targowski, P.; Gora, M.; Bajraszewski, T.; Szkulmowski, M.; Rouba, B.; Lekawa-Wyslouch, T.; Tyminska-Widmer, L.

    2006-01-01

    Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT), to tracking of deformations in paintings on canvas caused by periodical humidity changes are presented. The setup is able to monitor the position of a chosen point at the surface of a painting with micrometre precision, simultaneously in three dimensions, every 100 seconds. This allows recording of deformations associated with crack formation. For the particular painting model examined, it was shown that the surface moves in-plane towards the corner, and bulges outwards (Z-direction) in response to a rise in humidity. Subsequent to the first humidification/drying cycle, translation in the Z-direction is decreased, whilst in-plane translations increase somewhat. It was also shown that the response of the painting on canvas begins immediately on changing the relative humidity in the surroundings.

  16. Review of optical coherence tomography in oncology

    Science.gov (United States)

    Wang, Jianfeng; Xu, Yang; Boppart, Stephen A.

    2017-12-01

    The application of optical coherence tomography (OCT) in the field of oncology has been prospering over the past decade. OCT imaging has been used to image a broad spectrum of malignancies, including those arising in the breast, brain, bladder, the gastrointestinal, respiratory, and reproductive tracts, the skin, and oral cavity, among others. OCT imaging has initially been applied for guiding biopsies, for intraoperatively evaluating tumor margins and lymph nodes, and for the early detection of small lesions that would often not be visible on gross examination, tasks that align well with the clinical emphasis on early detection and intervention. Recently, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This paper reviews the evolution of OCT technologies for the clinical application of OCT in surgical and noninvasive interventional oncology procedures and concludes with a discussion of the future directions for OCT technologies, with particular emphasis on their applications in oncology.

  17. Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography.

    Science.gov (United States)

    Liu, Chih-Hao; Du, Yong; Singh, Manmohan; Wu, Chen; Han, Zhaolong; Li, Jiasong; Chang, Anthony; Mohan, Chandra; Larin, Kirill V

    2016-08-01

    Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Functional optical coherence tomography: principles and progress

    International Nuclear Information System (INIS)

    Kim, Jina; Levinson, Howard; Brown, William; Maher, Jason R.; Wax, Adam

    2015-01-01

    In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We review five principal extensions: Doppler OCT (DOCT), polarization-sensitive OCT (PS-OCT), optical coherence elastography (OCE), spectroscopic OCT (SOCT), and molecular imaging OCT. The former three have been further developed with studies in both ex vivo and in vivo human tissues. This review emphasizes the newer techniques of SOCT and molecular imaging OCT, which show excellent potential for clinical application but have yet to be well reviewed in the literature. SOCT elucidates tissue characteristics, such as oxygenation and carcinogenesis, by detecting wavelength-dependent absorption and scattering of light in tissues. While SOCT measures endogenous biochemical distributions, molecular imaging OCT detects exogenous molecular contrast agents. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to understand tissue activity that cannot be accomplished by other current imaging methodologies. (topical review)

  19. Dynamic light scattering optical coherence tomography.

    Science.gov (United States)

    Lee, Jonghwan; Wu, Weicheng; Jiang, James Y; Zhu, Bo; Boas, David A

    2012-09-24

    We introduce an integration of dynamic light scattering (DLS) and optical coherence tomography (OCT) for high-resolution 3D imaging of heterogeneous diffusion and flow. DLS analyzes fluctuations in light scattered by particles to measure diffusion or flow of the particles, and OCT uses coherence gating to collect light only scattered from a small volume for high-resolution structural imaging. Therefore, the integration of DLS and OCT enables high-resolution 3D imaging of diffusion and flow. We derived a theory under the assumption that static and moving particles are mixed within the OCT resolution volume and the moving particles can exhibit either diffusive or translational motion. Based on this theory, we developed a fitting algorithm to estimate dynamic parameters including the axial and transverse velocities and the diffusion coefficient. We validated DLS-OCT measurements of diffusion and flow through numerical simulations and phantom experiments. As an example application, we performed DLS-OCT imaging of the living animal brain, resulting in 3D maps of the absolute and axial velocities, the diffusion coefficient, and the coefficient of determination.

  20. Quantitative contrast-enhanced optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Winetraub, Yonatan; SoRelle, Elliott D. [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Liba, Orly [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Zerda, Adam de la [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States)

    2016-01-11

    We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within a voxel. Finally, high particle concentrations cause enough light attenuation to saturate the detected signal. Predictions were validated by comparison with measured OCT signals from gold nanorods (GNRs) prepared in water at concentrations ranging over five orders of magnitude (50 fM to 5 nM). In addition, we validated that our model accurately predicts the signal responses of GNRs in highly heterogeneous scattering environments including whole blood and living animals. By enabling particle quantification, this work provides a valuable tool for current and future contrast-enhanced in vivo OCT studies. More generally, the model described herein may inform the interpretation of detected signals in modalities that rely on coherence-based detection or are susceptible to interference effects.

  1. Intracoronary Optical Coherence Tomography: A Comprehensive Review: Clinical and Research Applications

    OpenAIRE

    Bezerra, Hiram G.; Costa, Marco A.; Guagliumi, Giulio; Rollins, Andrew M.; Simon, Daniel I.

    2009-01-01

    Cardiovascular optical coherence tomography (OCT) is a catheter-based invasive imaging system. Using light rather than ultrasound, OCT produces high-resolution in vivo images of coronary arteries and deployed stents. This comprehensive review will assist practicing interventional cardiologists in understanding the technical aspects of OCT based upon the physics of light and will also highlight the emerging research and clinical applications of OCT. Semi-automated imaging analyses of OCT syste...

  2. Optical coherence tomography: technology and applications (biological and medical physics, biomedical engineering)

    CERN Document Server

    2013-01-01

    Optical coherence tomography (OCT) is the optical analog of ultrasound imaging and is emerging as a powerful imaging technique that enables non-invasive, in vivo, high resolution, cross-sectional imaging in biological tissue. This book introduces OCT technology and applications not only from an optical and technological viewpoint, but also from biomedical and clinical perspectives. The chapters are written by leading research groups, in a style comprehensible to a broad audience.

  3. Breast ultrasound tomography with total-variation regularization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTIT.; Duric, Neb [KARMANOS CANCER INSTIT

    2009-01-01

    Breast ultrasound tomography is a rapidly developing imaging modality that has the potential to impact breast cancer screening and diagnosis. A new ultrasound breast imaging device (CURE) with a ring array of transducers has been designed and built at Karmanos Cancer Institute, which acquires both reflection and transmission ultrasound signals. To extract the sound-speed information from the breast data acquired by CURE, we have developed an iterative sound-speed image reconstruction algorithm for breast ultrasound transmission tomography based on total-variation (TV) minimization. We investigate applicability of the TV tomography algorithm using in vivo ultrasound breast data from 61 patients, and compare the results with those obtained using the Tikhonov regularization method. We demonstrate that, compared to the Tikhonov regularization scheme, the TV regularization method significantly improves image quality, resulting in sound-speed tomography images with sharp (preserved) edges of abnormalities and few artifacts.

  4. Dynamic Optical Coherence Tomography in Dermatology.

    Science.gov (United States)

    Ulrich, Martina; Themstrup, Lotte; de Carvalho, Nathalie; Manfredi, Marco; Grana, Costantino; Ciardo, Silvana; Kästle, Raphaela; Holmes, Jon; Whitehead, Richard; Jemec, Gregor B E; Pellacani, Giovanni; Welzel, Julia

    2016-01-01

    Optical coherence tomography (OCT) represents a non-invasive imaging technology, which may be applied to the diagnosis of non-melanoma skin cancer and which has recently been shown to improve the diagnostic accuracy of basal cell carcinoma. Technical developments of OCT continue to expand the applicability of OCT for different neoplastic and inflammatory skin diseases. Of these, dynamic OCT (D-OCT) based on speckle variance OCT is of special interest as it allows the in vivo evaluation of blood vessels and their distribution within specific lesions, providing additional functional information and consequently greater density of data. In an effort to assess the potential of D-OCT for future scientific and clinical studies, we have therefore reviewed the literature and preliminary unpublished data on the visualization of the microvasculature using D-OCT. Information on D-OCT in skin cancers including melanoma, as well as in a variety of other skin diseases, is presented in an atlas. Possible diagnostic features are suggested, although these require additional validation. © 2016 S. Karger AG, Basel.

  5. Scleral topography analysed by optical coherence tomography.

    Science.gov (United States)

    Bandlitz, Stefan; Bäumer, Joachim; Conrad, Uwe; Wolffsohn, James

    2017-08-01

    A detailed evaluation of the corneo-scleral-profile (CSP) is of particular relevance in soft and scleral lenses fitting. The aim of this study was to use optical coherence tomography (OCT) to analyse the profile of the limbal sclera and to evaluate the relationship between central corneal radii, corneal eccentricity and scleral radii. Using OCT (Optos OCT/SLO; Dunfermline, Scotland, UK) the limbal scleral radii (SR) of 30 subjects (11M, 19F; mean age 23.8±2.0SD years) were measured in eight meridians 45° apart. Central corneal radii (CR) and corneal eccentricity (CE) were evaluated using the Oculus Keratograph 4 (Oculus, Wetzlar, Germany). Differences between SR in the meridians and the associations between SR and corneal topography were assessed. Median SR measured along 45° (58.0; interquartile range, 46.8-84.8mm) was significantly (ptopography and may provide additional data useful in fitting soft and scleral contact lenses. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  6. Complex regression Doppler optical coherence tomography

    Science.gov (United States)

    Elahi, Sahar; Gu, Shi; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

    2018-04-01

    We introduce a new method to measure Doppler shifts more accurately and extend the dynamic range of Doppler optical coherence tomography (OCT). The two-point estimate of the conventional Doppler method is replaced with a regression that is applied to high-density B-scans in polar coordinates. We built a high-speed OCT system using a 1.68-MHz Fourier domain mode locked laser to acquire high-density B-scans (16,000 A-lines) at high enough frame rates (˜100 fps) to accurately capture the dynamics of the beating embryonic heart. Flow phantom experiments confirm that the complex regression lowers the minimum detectable velocity from 12.25 mm / s to 374 μm / s, whereas the maximum velocity of 400 mm / s is measured without phase wrapping. Complex regression Doppler OCT also demonstrates higher accuracy and precision compared with the conventional method, particularly when signal-to-noise ratio is low. The extended dynamic range allows monitoring of blood flow over several stages of development in embryos without adjusting the imaging parameters. In addition, applying complex averaging recovers hidden features in structural images.

  7. Optical coherence tomography in anterior segment imaging

    Science.gov (United States)

    Kalev-Landoy, Maya; Day, Alexander C.; Cordeiro, M. Francesca; Migdal, Clive

    2008-01-01

    Purpose To evaluate the ability of optical coherence tomography (OCT), designed primarily to image the posterior segment, to visualize the anterior chamber angle (ACA) in patients with different angle configurations. Methods In a prospective observational study, the anterior segments of 26 eyes of 26 patients were imaged using the Zeiss Stratus OCT, model 3000. Imaging of the anterior segment was achieved by adjusting the focusing control on the Stratus OCT. A total of 16 patients had abnormal angle configurations including narrow or closed angles and plateau irides, and 10 had normal angle configurations as determined by prior full ophthalmic examination, including slit-lamp biomicroscopy and gonioscopy. Results In all cases, OCT provided high-resolution information regarding iris configuration. The ACA itself was clearly visualized in patients with narrow or closed angles, but not in patients with open angles. Conclusions Stratus OCT offers a non-contact, convenient and rapid method of assessing the configuration of the anterior chamber. Despite its limitations, it may be of help during the routine clinical assessment and treatment of patients with glaucoma, particularly when gonioscopy is not possible or difficult to interpret. PMID:17355288

  8. Optical coherence tomography used for internal biometrics

    Science.gov (United States)

    Chang, Shoude; Sherif, Sherif; Mao, Youxin; Flueraru, Costel

    2007-06-01

    Traditional biometric technologies used for security and person identification essentially deal with fingerprints, hand geometry and face images. However, because all these technologies use external features of human body, they can be easily fooled and tampered with by distorting, modifying or counterfeiting these features. Nowadays, internal biometrics which detects the internal ID features of an object is becoming increasingly important. Being capable of exploring under-skin structure, optical coherence tomography (OCT) system can be used as a powerful tool for internal biometrics. We have applied fiber-optic and full-field OCT systems to detect the multiple-layer 2D images and 3D profile of the fingerprints, which eventually result in a higher discrimination than the traditional 2D recognition methods. More importantly, the OCT based fingerprint recognition has the ability to easily distinguish artificial fingerprint dummies by analyzing the extracted layered surfaces. Experiments show that our OCT systems successfully detected the dummy, which was made of plasticene and was used to bypass the commercially available fingerprint scanning system with a false accept rate (FAR) of 100%.

  9. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  10. Polarization sensitive optical coherence tomography detection method

    International Nuclear Information System (INIS)

    Colston, B W; DaSilva, L B; Everett, M J; Featherstone, J D B; Fried, D; Ragadio, J N; Sathyam, U S.

    1999-01-01

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattering coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions

  11. Submicron Resolution Spectral-Domain Optical Coherence Tomography

    KAUST Repository

    Alarousu, Erkki; Jabbour, Ghassan

    2013-01-01

    Apparatuses and systems for submicron resolution spectral-domain optical coherence tomography (OCT) are disclosed. The system may use white light sources having wavelengths within 400-1000 nanometers, and achieve resolution below 1 .mu

  12. Advanced integrated spectrometer designs for miniaturized optical coherence tomography systems

    NARCIS (Netherlands)

    Akça, B.I.; Povazay, B.; Chang, Lantian; Alex, A.; Worhoff, Kerstin; de Ridder, R.M.; Drexler, W.; Pollnau, Markus

    Optical coherence tomography (OCT) has enabled clinical applications that revolutionized in vivo medical diagnostics. Nevertheless, its current limitations owing to cost, size, complexity, and the need for accurate alignment must be overcome by radically novel approaches. Exploiting integrated

  13. Contribution de la tomographie par coherence optique au diagnostic ...

    African Journals Online (AJOL)

    Contribution de la tomographie par coherence optique au diagnostic de la neuropathie optique toxique. C.O.A. Abouki, S Alamou, C.R.A. Assavedo, L Odoulami-Yehouessi, I Sounouvou, S Hounnou-Tchabi ...

  14. Optical coherence tomography findings in methanol toxicity.

    Science.gov (United States)

    Klein, Kendra A; Warren, Alexis K; Baumal, Caroline R; Hedges, Thomas R

    2017-01-01

    Methanol toxicity poses a significant public health problem in developing countries, and in Southeast Asia, where the most common source of poisoning is via adulterated liquor in local drinks. Methanol toxicity can have devastating visual consequences and retinal specialists should be aware of the features of this toxic optic neuropathy. The authors report a case of severe systemic methanol toxicity and relatively mild optic neuropathy demonstrating unique retinal changes on optical coherence tomography (OCT). A previously healthy student developed ataxia, difficulty breathing and loss of consciousness hours after drinking homemade alcohol while traveling in Indonesia. She was found to have a serum pH of 6.79 and elevated methanol levels. She was treated with intravenous ethanol, methylprednisolone and sodium bicarbonate. When she awoke she had bilateral central scotomas. At presentation, she had central depression on visual field testing. OCT of the retinal nerve fiber layer (RNFL) was normal but ganglion cell layer analysis (GCL) showed highly selective loss of the nasal fibers in both eyes. Further, OCT of the macula demonstrated inner nuclear layer (INL) microcysts in the corresponding area of selective GCL loss in both eyes. The selective involvement of the papillomacular bundle fibers is common in toxic optic neuropathies and represents damage to the small caliber axons rich in mitochondria. Despite severe systemic toxicity, the relative sparing of the optic nerve in this case enabled characterization of the evolution of methanol toxicity with segmental GCL involvement and preservation of the RNFL, corresponding to the papillomacular bundle. This is the first reported case of INL microcysts in methanol optic neuropathy and supports that they are a non-specific finding, and may represent preferential damage to the papillomacular bundle.

  15. Motion contrast using optical coherence tomography

    Science.gov (United States)

    Fingler, Jeffrey Paul

    Diagnosis of ophthalmic diseases like age-related macular degeneration is very important for treatment of the disease as well as the development of future treatments. Optical coherence tomography (OCT) is an optical interference technique which can measure the three-dimensional structural information of the reflecting layers within a sample. In retinal imaging, OCT is used as the primary diagnostic tool for structural abnormalities such as retinal holes and detachments. The contrast within the images of this technique is based upon reflectivity changes from different regions of the retina. This thesis demonstrates the developments of methods used to produce additional contrast to the structural OCT images based on the tiny fluctuations of motion experienced by the mobile scatterers within a sample. Motion contrast was observed for motions smaller than 50 nm in images of a variety of samples. Initial contrast method demonstrations used Brownian motion differences to separate regions of a mobile Intralipid solution from a static agarose gel, chosen in concentration to minimize reflectivity contrast. Zebrafish embryos in the range of 3-4 days post fertilization were imaged using several motion contrast methods to determine the capabilities of identifying regions of vascular flow. Vasculature identification was demonstrated in zebrafish for blood vessels of all orientations as small as 10 microns in diameter. Mouse retinal imaging utilized the same motion contrast methods to determine the contrast capabilities for motions associated with vasculature within the retina. Improved contrast imaging techniques demonstrated comparable images to fluorescein angiography, the gold standard of retinal vascular imaging. Future studies can improve the demonstrated contrast analysis techniques and apply them towards human retinal motion contrast imaging for ophthalmic diagnostic purposes.

  16. Optical Biopsy Using Tissue Spectroscopy and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Norman S Nishioka

    2003-01-01

    Full Text Available ‘Optical biopsy’ or ‘optical diagnostics’ is a technique whereby light energy is used to obtain information about the structure and function of tissues without disrupting them. In fluorescence spectroscopy, light energy (usually provided by a laser is used to excite tissues and the resulting fluorescence provides information about the target tissue. Its major gastrointestinal application has been in the evaluation of colonic polyps, in which it can reliably distinguish malignant from benign lesions. Optical coherence tomography (OCT has been used in the investigation of Barrett’s epithelium (and dysplasia, although a variety of other applications are feasible. For example, OCT could assist in the identification and staging of mucosal and submucosal neoplasms, the grading of inflammation in the stomach and intestine, the diagnosis of biliary tumours and the assessment of villous architecture. OCT differs from endoscopic ultrasound, a complementary modality, in that it has a much higher resolution but lesser depth of penetration. The images correlate with the histopathological appearance of tissues, and the addition of Doppler methods may enable it to evaluate the vascularity of tumours and the amount of blood flow in varices. Refinements in these new optical techniques will likely make them valuable in clinical practice, although their specific roles have yet to be determined.

  17. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography.

    Science.gov (United States)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

    2016-05-20

    We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.

  18. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography

    Science.gov (United States)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

    2016-01-01

    We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging. PMID:27213392

  19. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Jonghyun Eom

    2016-05-01

    Full Text Available We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT and optical coherence tomography (OCT. The PAT remotely measures photoacoustic (PA signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF and a large-core multimode fiber (MMF. The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.

  20. Splenic abnormalities: a comparative review of ultrasound, microbubble-enhanced ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peddu, P.; Shah, M.; Sidhu, P.S. E-mail: paul.sidhu@kingsch.nhs.uk

    2004-09-01

    The ultrasound appearances of abnormalities of the spleen are reviewed and images compared with computed tomography. Focal lesions, both benign and malignant, trauma, infarction and congenital abnormalities are presented. The use of microbubble ultrasound contrast media as an aid to identifying and characterizing abnormalities is discussed.

  1. Functional swept source optical coherence tomography

    International Nuclear Information System (INIS)

    Blatter, C.

    2013-01-01

    Optical coherence tomography (OCT) is a non-invasive imaging modality capable of providing information about a sample structure along the three spatial dimensions with micrometer scale resolution. A new chapter opened with the development of functional OCT that provides additional information to the standard structural imaging. Among those extensions is Doppler OCT (D-OCT) that yields knowledge about the motion of the sample and/or its substructure. Its main application in biomedical imaging is the assessment of blood flow. D-OCT is therefore often associated with blood velocity measurement and recently with the visualization of the vascular network. Blood flow and vasculature are important markers of tissue health. Their assessment provides crucial information for diagnostics, treatment planning and monitoring. OCT is in a good position, as a non-invasive technique, to become an alternative to current fluorescence based techniques, allowing thereby also more frequent examination and broader screenings and, as a high resolution modality, to give insight into potential changes at the capillary level. An important challenge of in vivo imaging is patient motion that decreases the quality of acquisitions. One solution to that issue is high-speed imaging. Recently swept source OCT (SSOCT) revealed to be an efficient technology to achieve high-speed. This thesis investigates the use of swept sources for qualitative and quantitative vasculature imaging. It is presented via five journal papers that form its backbone. Prior to that, main concepts of FDOCT, D-OCT and SS systems are presented. The first paper reports a SSOCT system for skin imaging. In standard OCT systems, improving the lateral resolution comes at a cost of reduced depth of focus. This should be avoided in order to be able to assess different vascular beds in depth while keeping the speed advantage of FDOCT. Employing a Bessel beam for illumination of the sample allows circumventing this issue. The image

  2. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    OpenAIRE

    Adabi, Saba; Turani, Zahra; Fatemizadeh, Emad; Clayton, Anne; Nasiriavanaki, Mohammadreza

    2017-01-01

    Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the conseque...

  3. The Diagnosis of Spontaneous Coronary Artery Dissection by Optical Coherence Tomography.

    Science.gov (United States)

    Kanda, Takahiro; Tawarahara, Kei; Matsukura, Gaku; Matsunari, Masayoshi; Takabayashi, Rumi; Tamura, Jun; Ozeki, Mariko; Ukigai, Hiroshi

    2018-02-15

    Spontaneous coronary artery dissection (SCAD) is rare, but it frequently presents as acute myocardial infarction. It is frequently fatal and most cases are diagnosed at autopsy. We herein present the case of a 65-year-old woman with ST-elevation and myocardial infarction due to SCAD. Optical coherence tomography (OCT) helped us to confirm the diagnosis. The information on the intravascular morphology provided by OCT imaging is much more detailed in comparison to that provided by coronary angiography (CAG) and intravascular ultrasound (IVUS).

  4. Three-dimensional multifunctional optical coherence tomography for skin imaging

    Science.gov (United States)

    Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki

    2016-02-01

    Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

  5. Optical coherence tomography of the prostate nerves

    Science.gov (United States)

    Chitchian, Shahab

    Preservation of the cavernous nerves during prostate cancer surgery is critical in preserving a man's ability to have spontaneous erections following surgery. These microscopic nerves course along the surface of the prostate within a few millimeters of the prostate capsule, and they vary in size and location from one patient to another, making preservation of the nerves difficult during dissection and removal of a cancerous prostate gland. These observations may explain in part the wide variability in reported sexual potency rates (9--86%) following prostate cancer surgery. Any technology capable of providing improved identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery would be of great assistance in improving sexual function after surgery, and result in direct patient benefit. Optical coherence tomography (OCT) is a noninvasive optical imaging technique capable of performing high-resolution cross-sectional in vivo and in situ imaging of microstructures in biological tissues. OCT imaging of the cavernous nerves in the rat and human prostate has recently been demonstrated. However, improvements in the OCT system and the quality of the images for identification of the cavernous nerves is necessary before clinical use. The following chapters describe complementary approaches to improving identification and imaging of the cavernous nerves during OCT of the prostate gland. After the introduction to OCT imaging of the prostate gland, the optimal wavelength for deep imaging of the prostate is studied in Chapter 2. An oblique-incidence single point measurement technique using a normal-detector scanning system was implemented to determine the absorption and reduced scattering coefficients, mua and m's , of fresh canine prostate tissue, ex vivo, from the diffuse reflectance profile of near-IR light as a function of source-detector distance. The effective attenuation coefficient, mueff, and the Optical Penetration Depth (OPD) were

  6. [Evaluation of diabetic microangiopathy using optical coherence tomography angiography].

    Science.gov (United States)

    Czakó, Cecília; Sándor, Gábor László; Ecsedy, Mónika; Szepessy, Zsuzsanna; Borbándy, Ágnes; Resch, Miklós; Papp, András; Récsán, Zsuzsa; Horváth, Hajnalka; Nagy, Zoltán Zsolt; Kovács, Illés

    2018-02-01

    Optical coherence tomography angiography is a non-invasive imaging technique that is able to visualize the different retinal vascular layers using motion contrast to detect blood flow without intravenous dye injection. This method might help to assess microangiopathy in diabetic retinopathy during screening and follow-up. To quantify retinal microvasculature alterations in both eyes of diabetic patients in relation to systemic risk factors using optical coherence tomography angiography. Both eyes of 36 diabetic patients and 45 individuals without diabetes were examined. Duration of diabetes, insulin therapy, blood pressure, HbA 1c , dyslipidemia, axial length and the presence of diabetic retinopathy were recorded. Retinal vessel density was measured by optical coherence tomography angiography. The effect of risk factors on vessel density and between-eye asymmetry was assessed using multivariable regression analysis. Vessel density was significantly lower and between-eye difference was significantly higher in diabetic patients compared to controls (pdiabetes duration (pdiabetic retinopathy compared to control subjects (pdiabetes compared to healthy subjects. By using optical coherence tomography angiography, the detection of these microvascular alterations is possible before clinically detectable diabetic retinopathy and might serve as a useful tool in both screening and timing of treatment. Orv Hetil. 2018; 159(8): 320-326.

  7. The Development, Commercialization, and Impact of Optical Coherence Tomography

    Science.gov (United States)

    Fujimoto, James; Swanson, Eric

    2016-01-01

    This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function – diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an “ecosystem” consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact – all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest. PMID:27409459

  8. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    Directory of Open Access Journals (Sweden)

    O. G. Pozdeyeva

    2013-01-01

    Full Text Available Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of optical coherence tomography («RTVue-100,» USA. The fundography was carried out using a Nikon NF505‑AF (Japan fundus camera. All patients were examined with a Goldmann lens.Results: Optical coherence tomography was used to evaluate different kinds of peripheral retinal degenerations, such as lattice and snail track degeneration, isolated retinal tears, cystoid retinal degeneration, pathological hyperpigmentation, retinoschisis and cobblestone degeneration. The following morphometric data were studied: dimensions of the lesion (average length, retinal thickness along the edge of the lesion, retinal thickness at the base of the lesion and the vitreoretinal interface.Conclusion: Optical coherence tomography is a promising in vivo visualization method which is useful in evaluation of peripheral retinal degenerations, vitreoretinal adhesions and tractions. It also provides a comprehensive protocolling system and monitoring. It will enable ophthalmologists to better define laser and surgical treatment indications and evaluate therapy effectiveness.

  9. The Development, Commercialization, and Impact of Optical Coherence Tomography.

    Science.gov (United States)

    Fujimoto, James; Swanson, Eric

    2016-07-01

    This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function - diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an "ecosystem" consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact - all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest.

  10. Spectral-domain optical coherence tomography on a silicon chip

    NARCIS (Netherlands)

    Akça, B.I.

    2012-01-01

    Optical coherence tomography (OCT) is a non-invasive optical technique for high-resolution cross-sectional imaging of specimens, with many applications in clinical medicine and industry (e.g. materials testing, quality assurance, and process control). Current state-of-the-art OCT systems operate in

  11. Heartbeat OCT: In vivo intravascular megahertz-optical coherence tomography

    NARCIS (Netherlands)

    T. Wang (Tianshi); A.F.H. Pfeiffer (Andreas); E.S. Regar (Eveline); W. Wieser (Wolfgang); H.M.M. van Beusekom (Heleen); C.T. Lancée (Charles); T. Springeling (Tirza); I. Krabbendam (Ilona); A.F.W. van der Steen (Ton); R. Huber (Roman); G. van Soest (Gijs)

    2015-01-01

    textabstractCardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging

  12. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    Directory of Open Access Journals (Sweden)

    O. G. Pozdeyeva

    2014-07-01

    Full Text Available Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of optical coherence tomography («RTVue-100,» USA. The fundography was carried out using a Nikon NF505‑AF (Japan fundus camera. All patients were examined with a Goldmann lens.Results: Optical coherence tomography was used to evaluate different kinds of peripheral retinal degenerations, such as lattice and snail track degeneration, isolated retinal tears, cystoid retinal degeneration, pathological hyperpigmentation, retinoschisis and cobblestone degeneration. The following morphometric data were studied: dimensions of the lesion (average length, retinal thickness along the edge of the lesion, retinal thickness at the base of the lesion and the vitreoretinal interface.Conclusion: Optical coherence tomography is a promising in vivo visualization method which is useful in evaluation of peripheral retinal degenerations, vitreoretinal adhesions and tractions. It also provides a comprehensive protocolling system and monitoring. It will enable ophthalmologists to better define laser and surgical treatment indications and evaluate therapy effectiveness.

  13. Dispersion free full range spectral intensity optical coherence tomography

    DEFF Research Database (Denmark)

    Jensen, Mikkel; Israelsen, Niels Møller; Maria, Michael

    2017-01-01

    Optical coherence tomography (OCT) is a non-invasive imaging technique with many applications and widespread use in ophthalmology [1]. The axial resolution in OCT is inversely proportional to the bandwidth of the optical source used, but the improved axial resolution comes at the price of more...

  14. Modeling light–tissue interaction in optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Jørgensen, Thomas Martini; Thrane, Lars

    2015-01-01

    Optical coherence tomography (OCT) performs high-resolution, cross-sectional tomographic imaging of the internal tissue microstructure by measuring backscattered or backreflected light. The scope of this chapter is to present analytical and numerical models that are able to describe light-tissue ...

  15. Local inversions in ultrasound-modulated optical tomography

    International Nuclear Information System (INIS)

    Bal, Guillaume; Moskow, Shari

    2014-01-01

    Ultrasound-modulated optical tomography is a hybrid imaging modality that aims to combine the high contrast of optical waves with the high resolution of ultrasound. We follow the model of the influence of ultrasound modulation on the light intensity measurements developed in Bal and Schotland (2010 Phys. Rev. Lett. 104 043902). We present sufficient conditions ensuring that the absorption and diffusion coefficients modeling light propagation can locally be uniquely and stably reconstructed from the corresponding available information. We present an iterative procedure to solve such a problem based on the analysis of linear elliptic systems of redundant partial differential equations. (paper)

  16. Mesenteric Castleman's disease: ultrasound, computed tomography and angiographic appearance

    International Nuclear Information System (INIS)

    Malara, F.A.; Price, D.; Fabiny

    2000-01-01

    The localized form of Castleman's disease is rare, and a mesenteric location is particularly unusual. A case of an asymptomatic young woman having the hyaline vascular type is presented and the ultrasound, computed tomography (CT) and angiographic features of the condition are demonstrated. Copyright (1999) Blackwell Science Pty Ltd

  17. Synthetic focusing in ultrasound modulated tomography

    KAUST Repository

    Kuchment, Peter; Kunyansky, Leonid

    2010-01-01

    Several hybrid tomographic methods utilizing ultrasound modulation have been introduced lately. Success of these methods hinges on the feasibility of focusing ultrasound waves at an arbitrary point of interest. Such focusing, however, is difficult to achieve in practice. We thus propose a way to avoid the use of focused waves through what we call synthetic focusing, i.e. by reconstructing the would-be response to the focused modulation from the measurements corresponding to realistic unfocused waves. Examples of reconstructions from simulated data are provided. This non-technical paper describes only the general concept, while technical details will appear elsewhere. © 2010 American Institute of Mathematical Sciences.

  18. Synthetic focusing in ultrasound modulated tomography

    KAUST Repository

    Kuchment, Peter

    2010-09-01

    Several hybrid tomographic methods utilizing ultrasound modulation have been introduced lately. Success of these methods hinges on the feasibility of focusing ultrasound waves at an arbitrary point of interest. Such focusing, however, is difficult to achieve in practice. We thus propose a way to avoid the use of focused waves through what we call synthetic focusing, i.e. by reconstructing the would-be response to the focused modulation from the measurements corresponding to realistic unfocused waves. Examples of reconstructions from simulated data are provided. This non-technical paper describes only the general concept, while technical details will appear elsewhere. © 2010 American Institute of Mathematical Sciences.

  19. Ultrasound and multidetector computed tomography of mandibular ...

    African Journals Online (AJOL)

    Because of local invasivity and high metastatic potential, preoperative imaging evaluation of mandibular region and tumoral staging is essential along with biopsy sampling. The present manuscript describes the ultrasound and computed tomographic imaging findings of mandibular gland adenocarcinoma in two dogs and ...

  20. Reproducibility of abdominal fat assessment by ultrasound and computed tomography.

    Science.gov (United States)

    Mauad, Fernando Marum; Chagas-Neto, Francisco Abaeté; Benedeti, Augusto César Garcia Saab; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Carneiro, Antonio Adilton Oliveira; Muller, Enrico Mattana; Elias Junior, Jorge

    2017-01-01

    To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility.

  1. Reproducibility of abdominal fat assessment by ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mauad, Fernando Marum; Chagas-Neto, Francisco Abaete; Benedeti, Augusto Cesar Garcia Saab; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Carneiro, Antonio Adilton Oliveira; Muller, Enrico Mattana; Elias Junior, Jorge, E-mail: fernando@fatesa.edu.br [Faculdade de Tecnologia em Saude (FATESA), Ribeirao Preto, SP (Brazil); Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil). Departmento de Radiologia; Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Departmento de Medicina Clinica; Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Hospital Mae de Deus, Porto Alegre, RS (Brazil)

    2017-05-15

    Objective: To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. Materials and Methods: Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. Results: Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. Conclusion: In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility. (author)

  2. Spectral-domain optical coherence tomography of roth spots.

    Science.gov (United States)

    Giovinazzo, Jerome; Mrejen, Sarah; Freund, K Bailey

    2013-01-01

    To describe the retinal findings of subacute bacterial endocarditis, their evolution after treatment, and analysis with spectral-domain optical coherence tomography. Retrospective chart review. A 21-year-old man presented with the sudden onset of a central scotoma in his left eye because of a sub-internal limiting membrane hemorrhage overlying the left fovea. When examined 2 weeks later, Roth spots were noted in his right eye. The patient was immediately referred to his internist and diagnosed with subacute bacterial endocarditis with cultures positive for Streptococcus viridans. He subsequently underwent aortic valve replacement surgery after 4 weeks of intravenous antibiotic therapy. When examined 4 weeks after valve replacement surgery, there was regression of the Roth spots. The present case demonstrates the importance of a funduscopic examination in the early diagnosis and management of subacute bacterial endocarditis. The analysis of Roth spots with spectral-domain optical coherence tomography suggested that they were septic emboli.

  3. Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography.

    Science.gov (United States)

    Gordon, Andrew Y; Jayagopal, Ashwath

    2014-01-30

    Optical coherence tomography has emerged as valuable imaging modalityin ophthalmology and other fields by enabling high-resolution three-dimensional imaging of tissue. In this paper, we review recent progress in the field of contrast-enhanced optical coherence tomography (OCT). We discuss exogenous and endogenous sources of OCT contrast, focusing on their use with standard OCT systems as well as emerging OCT-based imaging modalities. We include advances in the processing of OCT data that generate improved tissue contrast, including spectroscopic OCT (SOCT), as well as work utilizing secondary light sources and/or detection mechanisms to create and detect enhanced contrast, including photothermal OCT (PTOCT) and photoacoustic OCT (PAOCT). Finally, we conclude with a discussion of the translational potential of these developments as well as barriers to their clinical use.

  4. Optical Coherence Tomography Angiography of Retinal Cavernous Hemangioma.

    Science.gov (United States)

    Pierro, Luisa; Marchese, Alessandro; Gagliardi, Marco; Bandello, Francesco

    2017-08-01

    Retinal cavernous hemangioma is a rare, benign, retinal tumor characterized by angiomatous proliferation of vessels within the inner retina or the optic disc.1 Here we report a case of retinal cavernous hemangioma on the margin of the optic disc in the right eye of a 61-year-old asymptomatic female. The lesion was studied with multimodal imaging which included structural optical coherence tomography, fluorescein angiography, blue fundus auto-fluorescence, optical coherence tomography angiography (OCTA) (DRI OCT Triton; Topcon, Tokyo, Japan) and visual field examination. Blood circulation inside retinal cavernous hemangioma lesion is typically low-stagnant.2 However, OCTA demonstrated blood flow inside the lesion, illustrating its vascular circulation.3 Visual field was within the normal limits, except from a slight enlargement of the blind spot. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:684-685.]. Copyright 2017, SLACK Incorporated.

  5. Optical coherence tomography in the diagnosis of actinic keratosis

    DEFF Research Database (Denmark)

    Friis, K B E; Themstrup, L; Jemec, G B E

    2017-01-01

    BACKGROUND: Optical coherence tomography (OCT) is a real-time non-invasive imaging tool, introduced in dermatology in the late 1990s. OCT uses near-infrared light impulses to produce images which can be displayed in cross-sectional and en-face mode. The technique has been used to image skin...... of layers consistent with absence of normal layered architecture in the skin. Thickened epidermis was found in 14/16 studies and white (hyperreflective) streaks and dots were described in 11/16 studies. In High-definition optical coherence tomography (HD-OCT) images disarranged epidermis (cross......-sectional images) along with an atypical honeycomb pattern (en-face images) was found in 5/5 studies and well-demarcated dermo-epithelial junction (DEJ) (cross-sectional images) was described in 3/5 studies. CONCLUSION: Several morphological characteristics of AKs were identified using Conventional OCT and HD...

  6. Application of optical coherence tomography angiography for diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Qing Liu

    2016-04-01

    Full Text Available Optical coherence tomography angiography(OCTAis a new emerging technology of the optical coherence tomography(OCTin recent years. It's a noninvasive and fast retinal vascular imaging technology with high resolution, and has been gradually applied to make diagnosis, gives treatment and follow-up for various types of retinal vascular diseases, such as diabetic retinopathy, choroid neovascularization, etc. OCTA has the unique advantages of layered observing the structure and shape of the chorioretinal vascular at different levels, and quantifying the blood flow index of designated scope and the flow area of lesions. However, OCTA requires high solid vision and good cooperation of patients, even has the limitations to observe the retinal scope and retinal vascular barrier function. With overcoming these limitations, it's helpful for us to improve the understanding of retinal vascular diseases, consummate the diagnosis and treatment and observation of retinal vascular diseases.

  7. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    Science.gov (United States)

    Adabi, Saba; Turani, Zahra; Fatemizadeh, Emad; Clayton, Anne; Nasiriavanaki, Mohammadreza

    2017-01-01

    Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts. PMID:28638245

  8. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    Directory of Open Access Journals (Sweden)

    Saba Adabi

    2017-06-01

    Full Text Available Optical coherence tomography (OCT delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts.

  9. Polarimetry noise in fiber-based optical coherence tomography instrumentation

    Science.gov (United States)

    Zhang, Ellen Ziyi; Vakoc, Benjamin J.

    2011-01-01

    High noise levels in fiber-based polarization-sensitive optical coherence tomography (PS-OCT) have broadly limited its clinical utility. In this study we investigate contribution of polarization mode dispersion (PMD) to the polarimetry noise. We develop numerical models of the PS-OCT system including PMD and validate these models with empirical data. Using these models, we provide a framework for predicting noise levels, for processing signals to reduce noise, and for designing an optimized system. PMID:21935044

  10. Optical coherence tomography--a new imaging method in ophthalmology.

    Science.gov (United States)

    Svorenova, I; Strmen, P; Olah, Z

    2010-01-01

    An improvement of examination methods in ophthalmology, technical digitalisation and knowledge of validity of examinations in various diseases contributes to early diagnostics, thereby leading to an opportunity for early treatment of eye disorders. Standard introduction of the so-called optical coherence tomography into the ophthamological clinical practice facilitated new options for a detailed analysis of pathological processes in the particular layers of the retina (Fig. 2, Ref. 5). Full Text (Free, PDF) www.bmj.sk.

  11. Submicron Resolution Spectral-Domain Optical Coherence Tomography

    KAUST Repository

    Alarousu, Erkki

    2013-11-14

    Apparatuses and systems for submicron resolution spectral-domain optical coherence tomography (OCT) are disclosed. The system may use white light sources having wavelengths within 400-1000 nanometers, and achieve resolution below 1 .mu.m. The apparatus is aggregated into a unitary piece, and a user can connect the apparatus to a user provided controller and/or light source. The light source may be a supercontinuum source.

  12. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    OpenAIRE

    O. G. Pozdeyeva; T. B. Shaimov; A. Yu. Galin; R. B. Shaimov; T. A. Shaimova; A. V. Zolotova; A. V. Fomin

    2014-01-01

    Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA) in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes) with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of op...

  13. Advanced Technologies for Ultrahigh Resolution and Functional Optical Coherence Tomography

    Science.gov (United States)

    2008-04-15

    Gorczynska, "Frequency domain optical coherence tomography techniques in eye imaging," Acta Physica Polonica A , vol. 102, pp. 739-46, 2002/12/ 2002. [57] S...other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a ...SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: a . REPORT b. ABSTRACT c. THIS PAGE 17. LIMITATION OF ABSTRACT

  14. Posterior lattice degeneration characterized by spectral domain optical coherence tomography.

    Science.gov (United States)

    Manjunath, Varsha; Taha, Mohammed; Fujimoto, James G; Duker, Jay S

    2011-03-01

    The purpose of this study was to use high-resolution spectral domain optical coherence tomography in the characterization of retinal and vitreal morphological changes overlying posterior lattice degeneration. A cross-sectional retrospective analysis was performed on 13 eyes of 13 nonconsecutive subjects with posterior lattice degeneration seen at the New England Eye Center, Tufts Medical Center between October 2009 and January 2010. Spectral domain optical coherence tomography images taken through the region of lattice degeneration were qualitatively analyzed. Four characteristic changes of the retina and vitreous were seen in the 13 eyes with lattice degeneration: 1) anterior/posterior U-shaped vitreous traction; 2) retinal breaks; 3) focal retinal thinning; and 4) vitreous membrane formation. The morphologic appearance of vitreous traction and retinal breaks were found to be consistent with previous histologic reports. It is possible to image posterior lattice degeneration in many eyes using spectral domain optical coherence tomography and to visualize the spectrum of retinal and vitreous changes throughout the area of lattice degeneration.

  15. Fourier phase in Fourier-domain optical coherence tomography

    Science.gov (United States)

    Uttam, Shikhar; Liu, Yang

    2015-01-01

    Phase of an electromagnetic wave propagating through a sample-of-interest is well understood in the context of quantitative phase imaging in transmission-mode microscopy. In the past decade, Fourier-domain optical coherence tomography has been used to extend quantitative phase imaging to the reflection-mode. Unlike transmission-mode electromagnetic phase, however, the origin and characteristics of reflection-mode Fourier phase are poorly understood, especially in samples with a slowly varying refractive index. In this paper, the general theory of Fourier phase from first principles is presented, and it is shown that Fourier phase is a joint estimate of subresolution offset and mean spatial frequency of the coherence-gated sample refractive index. It is also shown that both spectral-domain phase microscopy and depth-resolved spatial-domain low-coherence quantitative phase microscopy are special cases of this general theory. Analytical expressions are provided for both, and simulations are presented to explain and support the theoretical results. These results are further used to show how Fourier phase allows the estimation of an axial mean spatial frequency profile of the sample, along with depth-resolved characterization of localized optical density change and sample heterogeneity. Finally, a Fourier phase-based explanation of Doppler optical coherence tomography is also provided. PMID:26831383

  16. Fourier phase in Fourier-domain optical coherence tomography.

    Science.gov (United States)

    Uttam, Shikhar; Liu, Yang

    2015-12-01

    Phase of an electromagnetic wave propagating through a sample-of-interest is well understood in the context of quantitative phase imaging in transmission-mode microscopy. In the past decade, Fourier-domain optical coherence tomography has been used to extend quantitative phase imaging to the reflection-mode. Unlike transmission-mode electromagnetic phase, however, the origin and characteristics of reflection-mode Fourier phase are poorly understood, especially in samples with a slowly varying refractive index. In this paper, the general theory of Fourier phase from first principles is presented, and it is shown that Fourier phase is a joint estimate of subresolution offset and mean spatial frequency of the coherence-gated sample refractive index. It is also shown that both spectral-domain phase microscopy and depth-resolved spatial-domain low-coherence quantitative phase microscopy are special cases of this general theory. Analytical expressions are provided for both, and simulations are presented to explain and support the theoretical results. These results are further used to show how Fourier phase allows the estimation of an axial mean spatial frequency profile of the sample, along with depth-resolved characterization of localized optical density change and sample heterogeneity. Finally, a Fourier phase-based explanation of Doppler optical coherence tomography is also provided.

  17. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    International Nuclear Information System (INIS)

    Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-01-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

  18. Real-Time Laser Ultrasound Tomography for Profilometry of Solids

    Science.gov (United States)

    Zarubin, V. P.; Bychkov, A. S.; Karabutov, A. A.; Simonova, V. A.; Kudinov, I. A.; Cherepetskaya, E. B.

    2018-01-01

    We studied the possibility of applying laser ultrasound tomography for profilometry of solids. The proposed approach provides high spatial resolution and efficiency, as well as profilometry of contaminated objects or objects submerged in liquids. The algorithms for the construction of tomograms and recognition of the profiles of studied objects using the parallel programming technology NDIVIA CUDA are proposed. A prototype of the real-time laser ultrasound profilometer was used to obtain the profiles of solid surfaces of revolution. The proposed method allows the real-time determination of the surface position for cylindrical objects with an approximation accuracy of up to 16 μm.

  19. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

    OpenAIRE

    Tay, Elton Lik Tong; Yong, Vernon Khet Yau; Lim, Boon Ang; Sia, Stelson; Wong, Elizabeth Poh Ying; Yip, Leonard Wei Leon

    2015-01-01

    AIM: To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography (AS-OCT), as well as gonioscopy and spectral domain OCT (SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments. METHODS: Seventeen consecutive subjects (33 eyes) were recruited from the study hospital’s Glaucoma clinic. Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 ...

  20. Corneal thickness and elevation measurements using swept-source optical coherence tomography and slit scanning topography in normal and keratoconic eyes.

    Science.gov (United States)

    Jhanji, Vishal; Yang, Bingzhi; Yu, Marco; Ye, Cong; Leung, Christopher K S

    2013-11-01

    To compare corneal thickness and corneal elevation using swept source optical coherence tomography and slit scanning topography. Prospective study. 41 normal and 46 keratoconus subjects. All eyes were imaged using swept source optical coherence tomography and slit scanning tomography during the same visit. Mean corneal thickness and best-fit sphere measurements were compared between the instruments. Agreement of measurements between swept source optical coherence tomography and scanning slit topography was analyzed. Intra-rater reproducibility coefficient and intraclass correlation coefficient were evaluated. In normal eyes, central corneal thickness measured by swept source optical coherence tomography was thinner compared with slit scanning topography (p topography. In keratoconus eyes, central corneal thickness was thinner on swept source optical coherence tomography than slit scanning topography (p = 0.081) and ultrasound pachymetry (p = 0.001). There were significant differences between thinnest corneal thickness, and, anterior and posterior best-fit sphere measurements between both instruments (p topography. With better reproducibility coefficients and intraclass correlation coefficients, swept source optical coherence tomography may provide a reliable alternative for measurement of corneal parameters. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  1. Electrical impedance tomography imaging using a priori ultrasound data

    Directory of Open Access Journals (Sweden)

    Soleimani Manuchehr

    2006-02-01

    Full Text Available Abstract Background Different imaging systems (e.g. electrical, magnetic, and ultrasound rely on a wide variety of physical properties, and the datasets obtained from such systems provide only partial information about the unknown true state. One approach is to choose complementary imaging systems, and to combine the information to achieve a better representation. Methods This paper discusses the combination of ultrasound and electrical impedance tomography (EIT information. Ultrasound reflection signals are good at locating sharp acoustic density changes associated with the boundaries of objects. Some boundaries, however, may be indeterminable due to masking from intermediate boundaries or because they are outside the ultrasound beam. Conversely, the EIT data contains relatively low-quality information, but it includes the whole region enclosed by the electrodes. Results Results are shown from a narrowband level-set method applied to 2D and 3D EIT incorporating limited angle ultrasound time of flight data. Conclusion The EIT reconstruction is shown to be faster and more accurate using the additional edge information from both one and four transducer ultrasound systems.

  2. Intra-operative application of optical coherence tomography with an operating microscope.

    Science.gov (United States)

    Just, T; Lankenau, E; Hüttmann, G; Pau, H W

    2009-09-01

    To introduce the use of optical coherence tomography with an operating microscope for intra-operative evaluation of the human larynx. A specially equipped operating microscope with integrated spectral domain optical coherence tomography apparatus was used during microlaryngoscopy. Technical improvements in optical coherence tomography equipment (e.g. pilot beam, variable focal distance, improved image quality and integration into an operating microscope) have enabled greater sensitivity and imaging speed and a non-contact approach. Spectral domain optical coherence tomography now enables a better correlation between optical coherence tomography images and histological findings. With this new technology, the precision of biopsy can be improved during microlaryngoscopy. Use of this new optical coherence tomography technology, integrated into an operating microscope, enables the surgeon to define the biopsy site location and resection plane precisely, while the optical zoom of the operating microscope can be used over the complete range.

  3. Optical Coherence Tomography Angiography Features of Iris Racemose Hemangioma in 4 Cases.

    Science.gov (United States)

    Chien, Jason L; Sioufi, Kareem; Ferenczy, Sandor; Say, Emil Anthony T; Shields, Carol L

    2017-10-01

    Optical coherence tomography angiography (OCTA) allows visualization of iris racemose hemangioma course and its relation to the normal iris microvasculature. To describe OCTA features of iris racemose hemangioma. Descriptive, noncomparative case series at a tertiary referral center (Ocular Oncology Service of Wills Eye Hospital). Patients diagnosed with unilateral iris racemose hemangioma were included in the study. Features of iris racemose hemangioma on OCTA. Four eyes of 4 patients with unilateral iris racemose hemangioma were included in the study. Mean patient age was 50 years, all patients were white, and Snellen visual acuity was 20/20 in each case. All eyes had sectoral iris racemose hemangioma without associated iris or ciliary body solid tumor on clinical examination and ultrasound biomicroscopy. By anterior segment OCT, the racemose hemangioma was partially visualized in all cases. By OCTA, the hemangioma was clearly visualized as a uniform large-caliber vascular tortuous loop with intense flow characteristics superimposed over small-caliber radial iris vessels against a background of low-signal iris stroma. The vascular course on OCTA resembled a light bulb filament (filament sign), arising from the peripheral iris (base of light bulb) and forming a tortuous loop on reaching its peak (midfilament) near the pupil (n = 3) or midzonal iris (n = 1), before returning to the peripheral iris (base of light bulb). Intravenous fluorescein angiography performed in 1 eye depicted the iris hemangioma; however, small-caliber radial iris vessels were more distinct on OCTA than intravenous fluorescein angiography. Optical coherence tomography angiography is a noninvasive vascular imaging modality that clearly depicts the looping course of iris racemose hemangioma. Optical coherence tomography angiography depicted fine details of radial iris vessels, not distinct on intravenous fluorescein angiography.

  4. Multiple Scattering Model for Optical Coherence Tomography with Rytov Approximation

    KAUST Repository

    Li, Muxingzi

    2017-04-24

    Optical Coherence Tomography (OCT) is a coherence-gated, micrometer-resolution imaging technique that focuses a broadband near-infrared laser beam to penetrate into optical scattering media, e.g. biological tissues. The OCT resolution is split into two parts, with the axial resolution defined by half the coherence length, and the depth-dependent lateral resolution determined by the beam geometry, which is well described by a Gaussian beam model. The depth dependence of lateral resolution directly results in the defocusing effect outside the confocal region and restricts current OCT probes to small numerical aperture (NA) at the expense of lateral resolution near the focus. Another limitation on OCT development is the presence of a mixture of speckles due to multiple scatterers within the coherence length, and other random noise. Motivated by the above two challenges, a multiple scattering model based on Rytov approximation and Gaussian beam optics is proposed for the OCT setup. Some previous papers have adopted the first Born approximation with the assumption of small perturbation of the incident field in inhomogeneous media. The Rytov method of the same order with smooth phase perturbation assumption benefits from a wider spatial range of validity. A deconvolution method for solving the inverse problem associated with the first Rytov approximation is developed, significantly reducing the defocusing effect through depth and therefore extending the feasible range of NA.

  5. Optical coherence tomography a clinical and technical update

    CERN Document Server

    Cunha-Vaz, José

    2012-01-01

    Optical Coherence Tomography represents the ultimate noninvasive  ocular imaging technique although being in the field for over two-decades. This book encompasses both medical and technical developments and recent achievements. Here, the authors cover the field of application from the anterior to the posterior ocular segments (Part I) and present a comprehensive review on the development of OCT. Important developments towards  clinical applications are covered in Part II, ranging from the adaptive optics to the integration on a slit-lamp, and passing through new structural  and functional information extraction from OCT data. The book is intended to be informative, coherent and comprehensive for both the medical and technical communities and aims at easing the communication between the two fields and bridging the gap between the two scientific communities.

  6. Characterisation of optically cleared paper by optical coherence tomography

    International Nuclear Information System (INIS)

    Fabritius, T; Alarousu, E; Prykaeri, T; Hast, J; Myllylae, Risto

    2006-01-01

    Due to the highly light scattering nature of paper, the imaging depth of optical methods such as optical coherence tomography (OCT) is limited. In this work, we study the effect of refractive index matching on improving the imaging depth of OCT in paper. To this end, four different refractive index matching liquids (ethanol, 1-pentanol, glycerol and benzyl alcohol) with a refraction index between 1.359 and 1.538 were used in experiments. Low coherent light transmission was studied in commercial copy paper sheets, and the results indicate that benzyl alcohol offers the best improvement in imaging depth, while also being sufficiently stable for the intended purpose. Constructed cross-sectional images demonstrate visually that the imaging depth of OCT is considerably improved by optical clearing. Both surfaces of paper sheets can be detected along with information about the sheet's inner structure. (laser applications and other topics in quantum electronics)

  7. The APOSTEL recommendations for reporting quantitative optical coherence tomography studies

    DEFF Research Database (Denmark)

    Cruz-Herranz, Andrés; Balk, Lisanne J; Oberwahrenbrock, Timm

    2016-01-01

    OBJECTIVE: To develop consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results. METHODS: A panel of experienced OCT researchers (including 11 neurologists, 2 ophthalmologists, and 2 neuroscientists) discussed requirements for performing and reporting...... quantitative analyses of retinal morphology and developed a list of initial recommendations based on experience and previous studies. The list of recommendations was subsequently revised during several meetings of the coordinating group. RESULTS: We provide a 9-point checklist encompassing aspects deemed...... relevant when reporting quantitative OCT studies. The areas covered are study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition data analysis, recommended nomenclature, and statistical analysis. CONCLUSIONS...

  8. Dental calculus image based on optical coherence tomography

    Science.gov (United States)

    Hsieh, Yao-Sheng; Ho, Yi-Ching; Lee, Shyh-Yuan; Chuang, Ching-Cheng; Wang, Chun-Yang; Sun, Chia-Wei

    2011-03-01

    In this study, the dental calculus was characterized and imaged by means of swept-source optical coherence tomography (SSOCT). The refractive indices of enamel, dentin, cementum and calculus were measured as 1.625+/-0.024, 1.534+/-0.029, 1.570+/-0.021 and 1.896+/-0.085, respectively. The dental calculus lead strong scattering property and thus the region can be identified under enamel with SSOCT imaging. An extracted human tooth with calculus was covered by gingiva tissue as in vitro sample for SSOCT imaging.

  9. Optical coherence tomography for glucose monitoring in blood

    Science.gov (United States)

    Ullah, Hafeez; Hussain, Fayyaz; Ikram, Masroor

    2015-08-01

    In this review, we have discussed the potential application of the emerging imaging modality, i.e., optical coherence tomography (OCT) for glucose monitoring in biological tissues. OCT provides monitoring of glucose diffusion in different fibrous tissues like in sclera by determining the permeability rate with acceptable accuracy both in type 1 and in type 2 diabetes. The maximum precision of glucose measurement in Intralipid suspensions, for example, with the OCT technique yields the accuracy up to 4.4 mM for 10 % Intralipid and 2.2 mM for 3 % Intralipid.

  10. Optical coherence tomography for imaging of skin and skin diseases

    DEFF Research Database (Denmark)

    Mogensen, Mette; Thrane, Lars; Jørgensen, Thomas Martini

    2009-01-01

    Optical coherence tomography (OCT) is an emerging imaging technology based on light reflection. It provides real-time images with up to 2-mm penetration into the skin and a resolution of approximately 10 μm. It is routinely used in ophthalmology. The normal skin and its appendages have been studi...... technical solutions are being pursued to further improve the quality of the images and the data provided, and OCT is being integrated in multimodal imaging devices that would potentially be able to provide a quantum leap to the imaging of skin in vivo....

  11. Visible-light optical coherence tomography: a review

    Science.gov (United States)

    Shu, Xiao; Beckmann, Lisa; Zhang, Hao F.

    2017-12-01

    Visible-light optical coherence tomography (vis-OCT) is an emerging imaging modality, providing new capabilities in both anatomical and functional imaging of biological tissue. It relies on visible light illumination, whereas most commercial and investigational OCTs use near-infrared light. As a result, vis-OCT requires different considerations in engineering design and implementation but brings unique potential benefits to both fundamental research and clinical care of several diseases. Here, we intend to provide a summary of the development of vis-OCT and its demonstrated applications. We also provide perspectives on future technology improvement and applications.

  12. Detection of bladder tumors using optical coherence tomography

    Science.gov (United States)

    Pan, Yingtian; Xie, Tuqiang; Wang, Zhenguo

    2004-07-01

    This paper summarizes the engineering development of our lab for endoscopic optical coherence tomography toward the ultimate goal to image bladder micro architecture and to diagnose bladder cancers. To test the utility and potential limitations of OCT setups for bladder tumor diagnosis, we used a rat bladder cancer model to track the morphological changes following tumor growth. Image results are presented, suggesting that OCT is able to differentiate cancerous lesions from inflammatory lesions based on OCT characterizations of epithelial thickness and backscattering changes of bladder tissue.

  13. Spectral domain optical coherence tomography characteristics in diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Laxmi Gella

    2014-01-01

    Full Text Available Purpose: To report the appearance of diabetic retinopathy lesions using spectral domain optical coherence tomography (SD-OCT. Materials and Methods: A total of 287 eyes of 199 subjects were included. All the subjects underwent complete ophthalmic examination including SD-OCT. Results: The appearance of various lesions of diabetic retinopathy and the retinal layers involved were reported. In subjects with macular edema the prevalence of incomplete PVD was 55.6%. Conclusion: SD-OCT brings new insights into the morphological changes of the retina in diabetic retinopathy.

  14. Fiber optic based optical coherence tomography (OCT) for dental applications

    Energy Technology Data Exchange (ETDEWEB)

    Everett, M. J., LLNL

    1998-06-02

    We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity We have produced, using this scanning device, in viva cross-sectional images of hard and soft dental tissues in human volunteers Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento-enamel junction, were visible in all the images The dento-enamel junction and the alveolar bone were identifiable in approximately two thirds of the images These images represent, to our knowledge, the first in viva OCT images of human dental tissue.

  15. Advances in optical coherence tomography in dermatology-a review

    Science.gov (United States)

    Olsen, Jonas; Holmes, Jon; Jemec, Gregor B. E.

    2018-04-01

    Optical coherence tomography (OCT) was introduced as an imaging system, but like ultrasonography, other measures, such as blood perfusion and polarization of light, have enabled the technology to approach clinical utility. This review aims at providing an overview of the advances in clinical research based on the improving technical aspects. OCT provides cross-sectional and en face images down to skin depths of 0.4 to 2.00 mm with optical resolution of 3 to 15 μm. Dynamic optical coherence tomography (D-OCT) enables the visualization of cutaneous microvasculature via detection of rapid changes in the interferometric signal of blood flow. Nonmelanoma skin cancer (NMSC) is the most comprehensively investigated topic, resulting in improved descriptions of morphological features and diagnostic criteria. A refined scoring system for diagnosing NMSC, taking findings from conventional and D-OCT into account, is warranted. OCT diagnosis of melanoma is hampered by the resolution and the optical properties of melanin. D-OCT may be of value in diseases characterized with dynamic changes in the vasculature of the skin and the addition of functional measures is strongly encouraged. In conclusion, OCT in dermatology is still an emerging technology that has great potential for improving further in the future.

  16. Miniature endoscopic optical coherence tomography for calculus detection.

    Science.gov (United States)

    Kao, Meng-Chun; Lin, Chun-Li; Kung, Che-Yen; Huang, Yi-Fung; Kuo, Wen-Chuan

    2015-08-20

    The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement of an optical parameter [standard deviation (SD) of the optical coherence tomography (OCT) intensity] to differentiate subgingival calculus from sound enamel, including enamel pearl. Two-dimensional circumferential images were constructed by rotating the miniprobe (0.9 mm diameter) while acquiring image lines, and the adjacent lines in each rotation were stacked to generate a three-dimensional volume. In OCT images, compared to sound enamel and enamel pearls, dental calculus showed significant differences (Pdental calculus.

  17. High-speed optical coherence tomography signal processing on GPU

    International Nuclear Information System (INIS)

    Li Xiqi; Shi Guohua; Zhang Yudong

    2011-01-01

    The signal processing speed of spectral domain optical coherence tomography (SD-OCT) has become a bottleneck in many medical applications. Recently, a time-domain interpolation method was proposed. This method not only gets a better signal-to noise ratio (SNR) but also gets a faster signal processing time for the SD-OCT than the widely used zero-padding interpolation method. Furthermore, the re-sampled data is obtained by convoluting the acquired data and the coefficients in time domain. Thus, a lot of interpolations can be performed concurrently. So, this interpolation method is suitable for parallel computing. An ultra-high optical coherence tomography signal processing can be realized by using graphics processing unit (GPU) with computer unified device architecture (CUDA). This paper will introduce the signal processing steps of SD-OCT on GPU. An experiment is performed to acquire a frame SD-OCT data (400A-linesx2048 pixel per A-line) and real-time processed the data on GPU. The results show that it can be finished in 6.208 milliseconds, which is 37 times faster than that on Central Processing Unit (CPU).

  18. Endoscopic optical coherence tomography for imaging the tympanic membrane

    Science.gov (United States)

    Burkhardt, Anke; Walther, Julia; Cimalla, Peter; Bornitz, Matthias; Koch, Edmund

    2011-06-01

    Optical coherence tomography (OCT) is an imaging modality that enables micrometer-scale contactless subsurface imaging of biological tissue. Endoscopy, as another imaging method, has the potential of imaging tubular organs and cavities and therefore has opened up several application areas not accessible before. The combination of OCT and endoscopy uses the advantages of both methods and consequently allows additional imaging of structures beneath surfaces inside cavities. Currently, visual investigations on the surface of the human tympanic membrane are possible but only with expert eyes. up to now, visual imaging of the outer ear up to the tympanic membrane can be carried out by an otoscope, an operating microscope or an endoscope. In contrast to these devices, endoscopy has the advantage of imaging the whole tympanic membrane with one view. The intention of this research is the development of an endoscopic optical coherence tomography (EOCT) device for imaging the tympanic membrane depth-resolved and structures behind it. Detection of fluids in the middle ear, which function as an indicator for otitis media, could help to avoid the application of antibiotics. It is possible to detect a congeries of fluids with the otoscope but the ambition is to the early detection by OCT. The developed scanner head allows imaging in working distances in the range from zero up to 5 mm with a field of view of 2 mm. In the next step, the scanner head should be improved to increase the working distance and the field of view.

  19. The application of optical coherence tomography angiography in retinal diseases.

    Science.gov (United States)

    Sambhav, Kumar; Grover, Sandeep; Chalam, Kakarla V

    Optical coherence tomography angiography (OCTA) is a new, noninvasive imaging technique that generates real-time volumetric data on chorioretinal vasculature and its flow pattern. With the advent of high-speed optical coherence tomography, established enface chorioretinal segmentation, and efficient algorithms, OCTA generates images that resemble an angiogram. The principle of OCTA involves determining the change in backscattering between consecutive B-scans and then attributing the differences to the flow of erythrocytes through retinal blood vessels. OCTA has shown promise in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age-related macular degeneration, and retinal vascular occlusions. It quantifies vascular compromise reflecting the severity of diabetic retinopathy. OCTA detects the presence of choroidal neovascularization in exudative age-related macular degeneration and maps loss of choriocapillaris in nonexudative age-related macular degeneration. We describe principles of OCTA and findings in common and some uncommon retinal pathologies. Finally, we summarize its potential future applications. Its current limitations include a relatively small field of view, inability to show leakage, and a tendency for image artifacts. Further larger studies will define OCTAs utility in clinical settings and establish if the technology may offer its utility in decreasing morbidity through early detection and guide therapeutic interventions in retinal diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. High-speed optical coherence tomography by circular interferometric ranging

    Science.gov (United States)

    Siddiqui, Meena; Nam, Ahhyun S.; Tozburun, Serhat; Lippok, Norman; Blatter, Cedric; Vakoc, Benjamin J.

    2018-02-01

    Existing three-dimensional optical imaging methods excel in controlled environments, but are difficult to deploy over large, irregular and dynamic fields. This means that they can be ill-suited for use in areas such as material inspection and medicine. To better address these applications, we developed methods in optical coherence tomography to efficiently interrogate sparse scattering fields, that is, those in which most locations (voxels) do not generate meaningful signal. Frequency comb sources are used to superimpose reflected signals from equispaced locations through optical subsampling. This results in circular ranging, and reduces the number of measurements required to interrogate large volumetric fields. As a result, signal acquisition barriers that have limited speed and field in optical coherence tomography are avoided. With a new ultrafast, time-stretched frequency comb laser design operating with 7.6 MHz to 18.9 MHz repetition rates, we achieved imaging of multi-cm3 fields at up to 7.5 volumes per second.

  1. High resolution coherence domain depth-resolved nailfold capillaroscopy based on correlation mapping optical coherence tomography

    Science.gov (United States)

    Subhash, Hrebesh M.; O'Gorman, Sean; Neuhaus, Kai; Leahy, Martin

    2014-03-01

    In this paper we demonstrate a novel application of correlation mapping optical coherence tomography (cm-OCT) for volumetric nailfold capillaroscopy (NFC). NFC is a widely used non-invasive diagnostic method to analyze capillary morphology and microvascular abnormalities of nailfold area for a range of disease conditions. However, the conventional NFC is incapable of providing volumetric imaging, when volumetric quantitative microangiopathic parameters such as plexus morphology, capillary density, and morphologic anomalies of the end row loops most critical. cm-OCT is a recently developed well established coherence domain magnitude based angiographic modality, which takes advantage of the time-varying speckle effect, which is normally dominant in the vicinity of vascular regions compared to static tissue region. It utilizes the correlation coefficient as a direct measurement of decorrelation between two adjacent B-frames to enhance the visibility of depth-resolved microcirculation.

  2. Optical Coherence Tomography-Guided Decisions in Retinoblastoma Management.

    Science.gov (United States)

    Soliman, Sameh E; VandenHoven, Cynthia; MacKeen, Leslie D; Héon, Elise; Gallie, Brenda L

    2017-06-01

    Assess the role of handheld optical coherence tomography (OCT) in guiding management decisions during diagnosis, treatment, and follow-up of eyes affected by retinoblastoma. Retrospective, noncomparative, single-institution case series. All children newly diagnosed with retinoblastoma from January 2011 to December 2015 who had an OCT session during their active treatment at The Hospital for Sick Children (SickKids) in Toronto, Canada. The OCT sessions for fellow eyes of unilateral retinoblastoma without any suspicious lesion and those performed more than 6 months after the last treatment were excluded. Data collected included age at presentation, sex, family history, RB1 mutation status, 8th edition TNMH cancer staging and International Intraocular Retinoblastoma Classification (IIRC), and number of OCT sessions per eye. Details of each session were scored for indication-related details (informative or not) and assessed for guidance (directive or not), diagnosis (staging changed, new tumors found or excluded), treatment (modified, stopped, or modality shifted), or follow-up modified. Frequency of OCT-guided management decisions, stratified by indication and type of guidance (confirmatory vs. influential). Sixty-three eyes of 44 children had 339 OCT sessions over the course of clinical management (median number of OCT scans per eye, 5; range, 1-15). The age at presentation and presence of a heritable RB1 mutation significantly correlated with an increased number of OCT sessions. Indications included evaluation of post-treatment scar (55%) or fovea (16%), and posterior pole scanning for new tumors (11%). Of all sessions, 92% (312/339) were informative; 19 of 27 noninformative sessions had large, elevated lesions; of these, 14 of 19 were T2a or T2b (IIRC group C or D) eyes. In 94% (293/312) of the informative sessions, OCT directed treatment decisions (58%), diagnosis (16%), and follow-up (26%). Optical coherence tomography influenced and changed management from pre

  3. Spectralis optical coherence tomography findings in Welder′s maculopathy

    Directory of Open Access Journals (Sweden)

    Aniruddha Mahindrakar

    2013-01-01

    Full Text Available Welder′s maculopathy is a form of photochemical damage to the retina and is typically characterized by involvement of the outer retinal layers. Spectral domain optical coherence tomography (SD-OCT imaging was performed in three eyes of two patients with clinical findings suggestive of Welder′s maculopathy in occupational welders. A faceted foveal lesion characterized clinical examination and the SD-OCT line scans images showed a distinct discontinuity of the photoreceptor inner and outer segment (IS/OS junction. The external limiting membrane (ELM and the retinal pigment epithelial (RPE layer remained intact at the site of IS/OS defect. SD-OCT imaging offers a noninvasive way of evaluating the microstructural changes at the fovea in Welder′s maculopathy.

  4. Optical coherence tomography in gynecology: a narrative review

    Science.gov (United States)

    Kirillin, Mikhail; Motovilova, Tatiana; Shakhova, Natalia

    2017-12-01

    Modern gynecologic practice requires noninvasive diagnostics techniques capable of detecting morphological and functional alterations in tissues of female reproductive organs. Optical coherence tomography (OCT) is a promising tool for providing imaging of biotissues with high resolution at depths up to 2 mm. Design of the customized probes provides wide opportunities for OCT use in gynecology. This paper contains a retrospective insight into the history of OCT employment in gynecology, an overview of the existing gynecologic OCT probes, including those for combination with other diagnostic modalities, and state-of-the-art application of OCT for diagnostics of tumor and nontumor pathologies of female genitalia. Perspectives of OCT both in diagnostics and treatment planning and monitoring in gynecology are overviewed.

  5. Assessing embryo development using swept source optical coherence tomography

    Science.gov (United States)

    Caujolle, S.; Cernat, R.; Silvestri, G.; Marques, M. J.; Bradu, A.; Feuchter, T.; Robinson, G.; Griffin, D.; Podoleanu, A.

    2018-03-01

    A detailed assessment of embryo development would assist biologists with selecting the most suitable embryos for transfer leading to higher pregnancy rates. Currently, only low resolution microscopy is employed to perform this assessment. Although this method delivers some information on the embryo surface morphology, no specific details are shown related to its inner structure. Using a Master-Slave Swept-Source Optical Coherence Tomography (SS-OCT), images of bovine embryos from day 7 after fertilization were collected from different depths. The dynamic changes inside the embryos were examined, in detail and in real-time from several depths. To prove our ability to characterize the morphology, a single embryo was imaged over 26 hours. The embryo was deprived of its life support environment, leading to its death. Over this period, clear morphological changes were observed.

  6. Epidermal segmentation in high-definition optical coherence tomography.

    Science.gov (United States)

    Li, Annan; Cheng, Jun; Yow, Ai Ping; Wall, Carolin; Wong, Damon Wing Kee; Tey, Hong Liang; Liu, Jiang

    2015-01-01

    Epidermis segmentation is a crucial step in many dermatological applications. Recently, high-definition optical coherence tomography (HD-OCT) has been developed and applied to imaging subsurface skin tissues. In this paper, a novel epidermis segmentation method using HD-OCT is proposed in which the epidermis is segmented by 3 steps: the weighted least square-based pre-processing, the graph-based skin surface detection and the local integral projection-based dermal-epidermal junction detection respectively. Using a dataset of five 3D volumes, we found that this method correlates well with the conventional method of manually marking out the epidermis. This method can therefore serve to effectively and rapidly delineate the epidermis for study and clinical management of skin diseases.

  7. Colposcopic imaging using visible-light optical coherence tomography

    Science.gov (United States)

    Duan, Lian; McRaven, Michael D.; Liu, Wenzhong; Shu, Xiao; Hu, Jianmin; Sun, Cheng; Veazey, Ronald S.; Hope, Thomas J.; Zhang, Hao F.

    2017-05-01

    High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6×4.6-mm2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.

  8. Evaluation of microfluidic channels with optical coherence tomography

    KAUST Repository

    Czajkowski, J.; Prykä ri, T.; Alarousu, E.; Lauri, J.; Myllylä , R.

    2010-01-01

    Application of time domain, ultra high resolution optical coherence tomography (UHR-OCT) in evaluation of microfluidic channels is demonstrated. Presented study was done using experimental UHR-OCT device based on a Kerr-lens mode locked Ti:sapphire femtosecond laser, a photonic crystal fibre and modified, free-space Michelson interferometer. To show potential of the technique, microfluidic chip fabricated by VTT Center for Printed Intelligence (Oulu, Finland) was measured. Ability for full volumetric reconstruction in non-contact manner enabled complete characterization of closed entity of a microfluidic channel without contamination and harm for the sample. Measurement, occurring problems, and methods of postprocessing for raw data are described. Results present completely resolved physical structure of the channel, its spatial dimensions, draft angles and evaluation of lamination quality.

  9. Potential applications of optical coherence tomography angiography in glaucoma.

    Science.gov (United States)

    Dastiridou, Anna; Chopra, Vikas

    2018-05-01

    Optical coherence tomography angiography (OCTA) is a novel, noninvasive imaging modality that allows assessment of the retinal and choroidal vasculature. The scope of this review is to summarize recent studies using OCTA in glaucoma and highlight potential applications of this new technology in the field of glaucoma. OCTA studies have shown that retinal vascular changes may not develop solely as a result of advanced glaucoma damage. OCTA-derived measurements have provided evidence for lower retinal vascular densities at the optic nerve head, peripapillary and macula in preperimetric-glaucoma and early-glaucoma, as well as, in more advanced glaucoma, in comparison to with normal eyes. OCTA is a novel imaging modality that has already started to expand our knowledge base regarding the role of ocular blood flow in glaucoma. Future studies will better elucidate the role of OCTA-derived measurements in clinical practice, research, and clinical trials in glaucoma.

  10. Evaluation of microfluidic channels with optical coherence tomography

    KAUST Repository

    Czajkowski, J.

    2010-06-25

    Application of time domain, ultra high resolution optical coherence tomography (UHR-OCT) in evaluation of microfluidic channels is demonstrated. Presented study was done using experimental UHR-OCT device based on a Kerr-lens mode locked Ti:sapphire femtosecond laser, a photonic crystal fibre and modified, free-space Michelson interferometer. To show potential of the technique, microfluidic chip fabricated by VTT Center for Printed Intelligence (Oulu, Finland) was measured. Ability for full volumetric reconstruction in non-contact manner enabled complete characterization of closed entity of a microfluidic channel without contamination and harm for the sample. Measurement, occurring problems, and methods of postprocessing for raw data are described. Results present completely resolved physical structure of the channel, its spatial dimensions, draft angles and evaluation of lamination quality.

  11. Liquid sorption investigation of porous media by optical coherence tomography

    International Nuclear Information System (INIS)

    Fabritius, Tapio; Myllylae, Risto

    2006-01-01

    This paper introduces an alternative optical method to measuring liquid penetration into porous highly scattering media. Using pure glycerol, the method was tested by measuring glycerol sorption into cellulose fibre tissue with a grammage of 115 g m -2 . During the wetting process, dynamical changes in the scattering properties of the fibre tissue were detected by optical coherence tomography. Measurements were made from a single point on the front and back surface of a sample. Although the effect of penetration on the optical properties of a porous structure can be seen independent of measurement direction, the border between the dry and wetted area is detectable only in front surface measurements. In addition, the paper experimentally investigates the temporally and spatially dependent swelling behaviour of paper

  12. In vivo endoscopic multi-beam optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Standish, Beau A; Mariampillai, Adrian; Munce, Nigel R; Leung, Michael K K; Vitkin, I Alex [Deptartment of Medical Biophysics, University of Toronto, Toronto (Canada); Lee, Kenneth K C; Yang, Victor X D [Ontario Cancer Institute/University Health Network, Toronto (Canada)], E-mail: standish@ee.ryerson.ca

    2010-02-07

    A multichannel optical coherence tomography (multi-beam OCT) system and an in vivo endoscopic imaging probe were developed using a swept-source OCT system. The distal optics were micro-machined to produce a high numerical aperture, multi-focus fibre optic array. This combination resulted in a transverse design resolution of <10 {mu}m full width half maximum (FWHM) throughout the entire imaging range, while also increasing the signal intensity within the focus of the individual channels. The system was used in a pre-clinical rabbit study to acquire in vivo structural images of the colon and ex vivo images of the oesophagus and trachea. A good correlation between the structural multi-beam OCT images and H and E histology was achieved, demonstrating the feasibility of this high-resolution system and its potential for in vivo human endoscopic imaging.

  13. In vivo endoscopic multi-beam optical coherence tomography

    International Nuclear Information System (INIS)

    Standish, Beau A; Mariampillai, Adrian; Munce, Nigel R; Leung, Michael K K; Vitkin, I Alex; Lee, Kenneth K C; Yang, Victor X D

    2010-01-01

    A multichannel optical coherence tomography (multi-beam OCT) system and an in vivo endoscopic imaging probe were developed using a swept-source OCT system. The distal optics were micro-machined to produce a high numerical aperture, multi-focus fibre optic array. This combination resulted in a transverse design resolution of <10 μm full width half maximum (FWHM) throughout the entire imaging range, while also increasing the signal intensity within the focus of the individual channels. The system was used in a pre-clinical rabbit study to acquire in vivo structural images of the colon and ex vivo images of the oesophagus and trachea. A good correlation between the structural multi-beam OCT images and H and E histology was achieved, demonstrating the feasibility of this high-resolution system and its potential for in vivo human endoscopic imaging.

  14. Optical coherence tomography of the living human kidney

    Directory of Open Access Journals (Sweden)

    Peter M. Andrews

    2014-03-01

    Full Text Available Acute tubular necrosis (ATN induced by ischemia is the most common insult to donor kidneys destined for transplantation. ATN results from swelling and subsequent damage to cells lining the kidney tubules. In this study, we demonstrate the capability of optical coherence tomography (OCT to image the renal microstructures of living human donor kidneys and potentially provide a measure to determine the extent of ATN. We also found that Doppler-based OCT (i.e., DOCT reveals renal blood flow dynamics that is another major factor which could relate to post-transplant renal function. All OCT/DOCT observations were performed in a noninvasive, sterile and timely manner on intact human kidneys both prior to (ex vivo and following (in vivo their transplantation. Our results indicate that this imaging model provides transplant surgeons with an objective visualization of the transplant kidneys prior and immediately post transplantation.

  15. One step geometrical calibration method for optical coherence tomography

    International Nuclear Information System (INIS)

    Díaz, Jesús Díaz; Ortmaier, Tobias; Stritzel, Jenny; Rahlves, Maik; Reithmeier, Eduard; Roth, Bernhard; Majdani, Omid

    2016-01-01

    We present a novel one-step calibration methodology for geometrical distortion correction for optical coherence tomography (OCT). A calibration standard especially designed for OCT is introduced, which consists of an array of inverse pyramidal structures. The use of multiple landmarks situated on four different height levels on the pyramids allow performing a 3D geometrical calibration. The calibration procedure itself is based on a parametric model of the OCT beam propagation. It is validated by experimental results and enables the reduction of systematic errors by more than one order of magnitude. In future, our results can improve OCT image reconstruction and interpretation for medical applications such as real time monitoring of surgery. (paper)

  16. Optical Coherence Tomography Imaging in Acute Coronary Syndromes

    Directory of Open Access Journals (Sweden)

    Takashi Kubo

    2011-01-01

    Full Text Available Optical coherence tomography (OCT is a high-resolution imaging technique that offers microscopic visualization of coronary plaques. The clear and detailed images of OCT generate an intense interest in adopting this technique for both clinical and research purposes. Recent studies have shown that OCT is useful for the assessment of coronary atherosclerotic plaques, in particular the assessment of plaque rupture, erosion, and intracoronary thrombus in patients with acute coronary syndrome. In addition, OCT may enable identifying thin-cap fibroatheroma, the proliferation of vasa vasorum, and the distribution of macrophages surrounding vulnerable plaques. With its ability to view atherosclerotic lesions in vivo with such high resolution, OCT provides cardiologists with the tool they need to better understand the thrombosis-prone vulnerable plaques and acute coronary syndromes. This paper reviews the possibility of OCT for identification of vulnerable plaques in vivo.

  17. Endoscopic optical coherence tomography with a focus-adjustable probe.

    Science.gov (United States)

    Liao, Wenchao; Chen, Tianyuan; Wang, Chengming; Zhang, Wenxin; Peng, Zhangkai; Zhang, Xiao; Ai, Shengnan; Fu, Deyong; Zhou, Tieying; Xue, Ping

    2017-10-15

    We present a focus-adjustable endoscopic probe for optical coherence tomography (OCT), which is able to acquire images with different focal planes and overcome depth-of-focus limitations by image fusing. The use of a two-way shape-memory-alloy spring enables the probe to adjust working distance over 1.5 mm, providing a large scanning range with high resolution and no sensitivity loss. Equipped with a homemade hollow-core ultrasonic motor, the probe is capable of performing an unobstructed 360 deg field-of-view distal scanning. Both the axial resolution and the best lateral resolution are ∼4  μm, with a sensitivity of 100.3 dB. Spectral-domain OCT imaging of phantom and biological tissues with the probe is also demonstrated.

  18. Indications of Optical Coherence Tomography in Keratoplasties: Literature Review

    Directory of Open Access Journals (Sweden)

    Thiago Trindade Nesi

    2012-01-01

    Full Text Available Optical coherence tomography (OCT of the anterior segment, in particular corneal OCT, has become a reliable tool for the cornea specialist, as it provides the acquisition of digital images at high resolution with a noncontact technology. In penetrating or lamellar keratoplasties, OCT can be used to assess central corneal thickness and pachymetry maps, as well as precise measurements of deep stromal opacities, thereby guiding the surgeon to choose the best treatment option. OCT has also been used to evaluate the keratoplasty postoperative period, for early identification of possible complications, such as secondary glaucoma or donor disc detachments in endothelial keratoplasties. Intraoperatively, OCT can be used to assess stromal bed regularity and transparency in anterior lamellar surgeries, especially for those techniques in which a bare Descemet’s membrane is the goal. The purpose of this paper is to review and discuss the role of OCT as a diagnostic tool in various types of keratoplasties.

  19. Imaging of oral pathological tissue using optical coherence tomography

    Science.gov (United States)

    Canjau, Silvana; Todea, Carmen; Sinescu, Cosmin; Duma, Virgil-Florin; Topala, Florin I.; Podoleanu, Adrian G.

    2014-01-01

    Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival. Interaction of light with tissues may highlight changes in tissue structure and metabolism. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method, being a new high-resolution optical technique that permits tri-dimensional (3-D), real-time imaging of near surface abnormalities in complex tissues. In this study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT investigation. Histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images. The elements obserced included extensive epithelial down-growth, the disruption of the basement membrane, with areas of erosion, an epithelial layer that was highly variable in thickness and invasion into the sub-epithelial layers. Therefore, OCT appears to be a highly promising imaging modality.

  20. Evaluation of microfluidic channels with optical coherence tomography

    Science.gov (United States)

    Czajkowski, J.; Prykäri, T.; Alarousu, E.; Lauri, J.; Myllylä, R.

    2010-11-01

    Application of time domain, ultra high resolution optical coherence tomography (UHR-OCT) in evaluation of microfluidic channels is demonstrated. Presented study was done using experimental UHR-OCT device based on a Kerr-lens mode locked Ti:sapphire femtosecond laser, a photonic crystal fibre and modified, free-space Michelson interferometer. To show potential of the technique, microfluidic chip fabricated by VTT Center for Printed Intelligence (Oulu, Finland) was measured. Ability for full volumetric reconstruction in non-contact manner enabled complete characterization of closed entity of a microfluidic channel without contamination and harm for the sample. Measurement, occurring problems, and methods of postprocessing for raw data are described. Results present completely resolved physical structure of the channel, its spatial dimensions, draft angles and evaluation of lamination quality.

  1. Renal imaging with radionuclides, ultrasound, and computed tomography

    International Nuclear Information System (INIS)

    Kahn, P.C.

    1979-01-01

    Nuclear medicine, ultrasound, and computed tomography have all contributed greatly to the diagnosis and understanding of renal disease. The /sup 99m/Tc-glucoheptonate scan is a multipurpose test for evaluating blood flow, cortical function and excretion, and the location of renal tissue. It is especially useful in renal trauma and vascular disease, congenital anomalies, and pseudomasses. Technetium-99m diethylene triamine pentaacetic acid (DTPA) is most helpful in evaluating obstruction and reflux, and 67 Ga citrate has a major role in inflammatory disease. The gray-scale ultrasound examination helps to characterize masses as cysts, abscesses, or tumors, and is particularly helpful in localization for aspiration, biopsy, or drainage procedures. Its total innocuousness makes echography useful for sequential follow-up in hydronephrosis and masses. Computed tomography with a fast scanner allows the identification of small lesions, and gives the most anatomic information. It permits the differentiation of fat from pelvic tumors and small cysts from neoplasms, and clearly identifies perirenal structures. With contrast enhancement, additional information about the vascularity of lesions is obtained. Although these tests use different physical principles and instruments, the data they provide are often similar, and for practical purposes the use of one modality may preclude the use of others. Difficult judgments are required to make certain that the proper examination or sequence of examinations is done in each case

  2. Optical coherence tomography visualizes neurons in human entorhinal cortex

    Science.gov (United States)

    Magnain, Caroline; Augustinack, Jean C.; Konukoglu, Ender; Frosch, Matthew P.; Sakadžić, Sava; Varjabedian, Ani; Garcia, Nathalie; Wedeen, Van J.; Boas, David A.; Fischl, Bruce

    2015-01-01

    Abstract. The cytoarchitecture of the human brain is of great interest in diverse fields: neuroanatomy, neurology, neuroscience, and neuropathology. Traditional histology is a method that has been historically used to assess cell and fiber content in the ex vivo human brain. However, this technique suffers from significant distortions. We used a previously demonstrated optical coherence microscopy technique to image individual neurons in several square millimeters of en-face tissue blocks from layer II of the human entorhinal cortex, over 50  μm in depth. The same slices were then sectioned and stained for Nissl substance. We registered the optical coherence tomography (OCT) images with the corresponding Nissl stained slices using a nonlinear transformation. The neurons were then segmented in both images and we quantified the overlap. We show that OCT images contain information about neurons that is comparable to what can be obtained from Nissl staining, and thus can be used to assess the cytoarchitecture of the ex vivo human brain with minimal distortion. With the future integration of a vibratome into the OCT imaging rig, this technique can be scaled up to obtain undistorted volumetric data of centimeter cube tissue blocks in the near term, and entire human hemispheres in the future. PMID:25741528

  3. Detection of brain tumor margins using optical coherence tomography

    Science.gov (United States)

    Juarez-Chambi, Ronald M.; Kut, Carmen; Rico-Jimenez, Jesus; Campos-Delgado, Daniel U.; Quinones-Hinojosa, Alfredo; Li, Xingde; Jo, Javier

    2018-02-01

    In brain cancer surgery, it is critical to achieve extensive resection without compromising adjacent healthy, non-cancerous regions. Various technological advances have made major contributions in imaging, including intraoperative magnetic imaging (MRI) and computed tomography (CT). However, these technologies have pros and cons in providing quantitative, real-time and three-dimensional (3D) continuous guidance in brain cancer detection. Optical Coherence Tomography (OCT) is a non-invasive, label-free, cost-effective technique capable of imaging tissue in three dimensions and real time. The purpose of this study is to reliably and efficiently discriminate between non-cancer and cancer-infiltrated brain regions using OCT images. To this end, a mathematical model for quantitative evaluation known as the Blind End- Member and Abundances Extraction method (BEAE). This BEAE method is a constrained optimization technique which extracts spatial information from volumetric OCT images. Using this novel method, we are able to discriminate between cancerous and non-cancerous tissues and using logistic regression as a classifier for automatic brain tumor margin detection. Using this technique, we are able to achieve excellent performance using an extensive cross-validation of the training dataset (sensitivity 92.91% and specificity 98.15%) and again using an independent, blinded validation dataset (sensitivity 92.91% and specificity 86.36%). In summary, BEAE is well-suited to differentiate brain tissue which could support the guiding surgery process for tissue resection.

  4. Microvascular anastomosis in rodent model evaluated by Fourier domain Doppler optical coherence tomography

    Science.gov (United States)

    Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.

    2014-03-01

    Vascular and microvascular anastomosis are critical components of reconstructive microsurgery, vascular surgery and transplant surgery. Imaging modality that provides immediate, real-time in-depth view and 3D structure and flow information of the surgical site can be a great valuable tool for the surgeon to evaluate surgical outcome following both conventional and innovative anastomosis techniques, thus potentially increase the surgical success rate. Microvascular anastomosis for vessels with outer diameter smaller than 1.0 mm is extremely challenging and effective evaluation of the outcome is very difficult if not impossible using computed tomography (CT) angiograms, magnetic resonance (MR) angiograms and ultrasound Doppler. Optical coherence tomography (OCT) is a non-invasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. Phaseresolved Doppler OCT that explores the phase information of OCT signals has been shown to be capable of characterizing dynamic blood flow clinically. In this work, we explore the capability of Fourier domain Doppler OCT as an evaluation tool to detect commonly encountered post-operative complications that will cause surgical failure and to confirm positive result with surgeon's observation. Both suture and cuff based techniques were evaluated on the femoral artery and vein in the rodent model.

  5. Investigation of tissue cellularity at the tip of the core biopsy needle with optical coherence tomography.

    Science.gov (United States)

    Iftimia, Nicusor; Park, Jesung; Maguluri, Gopi; Krishnamurthy, Savitri; McWatters, Amanda; Sabir, Sharjeel H

    2018-02-01

    We report the development and the pre-clinical testing of a new technology based on optical coherence tomography (OCT) for investigating tissue composition at the tip of the core biopsy needle. While ultrasound, computed tomography, and magnetic resonance imaging are routinely used to guide needle placement within a tumor, they still do not provide the resolution needed to investigate tissue cellularity (ratio between viable tumor and benign stroma) at the needle tip prior to taking a biopsy core. High resolution OCT imaging, however, can be used to investigate tissue morphology at the micron scale, and thus to determine if the biopsy core would likely have the expected composition. Therefore, we implemented this capability within a custom-made biopsy gun and evaluated its capability for a correct estimation of tumor tissue cellularity. A pilot study on a rabbit model of soft tissue cancer has shown the capability of this technique to provide correct evaluation of tumor tissue cellularity in over 85% of the cases. These initial results indicate the potential benefit of the OCT-based approach for improving the success of the core biopsy procedures.

  6. Optical coherence tomography-enhanced microlaryngoscopy: preliminary report of a noncontact optical coherence tomography system integrated with a surgical microscope.

    Science.gov (United States)

    Vokes, David E; Jackson, Ryan; Guo, Shuguang; Perez, Jorge A; Su, Jianping; Ridgway, James M; Armstrong, William B; Chen, Zhongping; Wong, Brian J F

    2008-07-01

    Optical coherence tomography (OCT) is a new imaging modality that uses near-infrared light to produce cross-sectional images of tissue with a resolution approaching that of light microscopy. We have previously reported use of OCT imaging of the vocal folds (VFs) during direct laryngoscopy with a probe held in contact or near-contact with the VFs. This aim of this study was to develop and evaluate a novel OCT system integrated with a surgical microscope to allow hands-free OCT imaging of the VFs, which could be performed simultaneously with microscopic visualization. We performed a prospective evaluation of a new method of acquiring OCT images of the VFs. An OCT system was successfully integrated with a surgical microscope to permit noncontact OCT imaging of the VFs of 10 patients. With this novel device we were able to identify VF epithelium and lamina propria; however, the resolution was reduced compared to that achieved with the standard contact or near-contact OCT. Optical coherence tomography is able to produce high-resolution images of vocal fold mucosa to a maximum depth of 1.6 mm. It may be used in the diagnosis of VF lesions, particularly early squamous cell carcinoma, in which OCT can show disruption of the basement membrane. Mounting the OCT device directly onto the operating microscope allows hands-free noncontact OCT imaging and simultaneous conventional microscopic visualization of the VFs. However, the lateral resolution of the OCT microscope system is 50 microm, in contrast to the conventional handheld probe system (10 microm). Although such images at this resolution are still useful clinically, improved resolution would enhance the system's performance, potentially enabling real-time OCT-guided microsurgery of the larynx.

  7. Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology - Technical note

    DEFF Research Database (Denmark)

    Falk, Erling

    2014-01-01

    . Here, a new method for optimising cardiac coronary CT with optical coherence tomography (OCT) and histopathology is presented. Materials and methods: Twenty human hearts obtained from autopsies were used. A contrast agent that solidifies after cooling was injected into the coronary arteries. CT...... of the images was also developed. Results: We have succeeded in developing a new method for post-mortem coronary CT angiography in which an autopsy heart is placed in a chest phantom to simulate clinical CT. Conclusion: The new method permits comparison of CT with OCT and histopathology. This method can also...

  8. Donor disc attachment assessment with intraoperative spectral optical coherence tomography during descemet stripping automated endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Edward Wylegala

    2013-01-01

    Full Text Available Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT. We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment.

  9. Computed tomography and ultrasound of the normal pancreas

    International Nuclear Information System (INIS)

    Kolmannskog, F.; Swensen, T.; Vatn, M.H.; Larsen, S.

    1982-01-01

    Computed tomography (CT) and ultrasound (US) were performed on 47 patients with a normal pancreas. CT was a significantly better method than US to demonstrate the pancreatic body and tail. The pancreatic head was also shown more often using CT than US, but this difference was not statistically significant. The diameters of the different parts of the pancreas measured at CT were significantly larger than measured at US. The explanation is most probably that the widths of the splenic and superior mesenteric veins are added to the diameters of the pancreas measured at CT, while using US, these vessels are clearly differentiated from the pancreatic tissue. US was a significantly better technique than CT to register the vascular structures surrounding the pancreas, except from the left renal vein, which was more often demonstrated at CT. (Auth.)

  10. Optical coherence tomography and optical coherence domain reflectometry for deep brain stimulation probe guidance

    Science.gov (United States)

    Jeon, Sung W.; Shure, Mark A.; Baker, Kenneth B.; Chahlavi, Ali; Hatoum, Nagi; Turbay, Massud; Rollins, Andrew M.; Rezai, Ali R.; Huang, David

    2005-04-01

    Deep Brain Stimulation (DBS) is FDA-approved for the treatment of Parkinson's disease and essential tremor. Currently, placement of DBS leads is guided through a combination of anatomical targeting and intraoperative microelectrode recordings. The physiological mapping process requires several hours, and each pass of the microelectrode into the brain increases the risk of hemorrhage. Optical Coherence Domain Reflectometry (OCDR) in combination with current methodologies could reduce surgical time and increase accuracy and safety by providing data on structures some distance ahead of the probe. For this preliminary study, we scanned a rat brain in vitro using polarization-insensitive Optical Coherence Tomography (OCT). For accurate measurement of intensity and attenuation, polarization effects arising from tissue birefringence are removed by polarization diversity detection. A fresh rat brain was sectioned along the coronal plane and immersed in a 5 mm cuvette with saline solution. OCT images from a 1294 nm light source showed depth profiles up to 2 mm. Light intensity and attenuation rate distinguished various tissue structures such as hippocampus, cortex, external capsule, internal capsule, and optic tract. Attenuation coefficient is determined by linear fitting of the single scattering regime in averaged A-scans where Beer"s law is applicable. Histology showed very good correlation with OCT images. From the preliminary study using OCT, we conclude that OCDR is a promising approach for guiding DBS probe placement.

  11. Integral ceramic superstructure evaluation using time domain optical coherence tomography

    Science.gov (United States)

    Sinescu, Cosmin; Bradu, Adrian; Topala, Florin I.; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Podoleanu, Adrian G.

    2014-02-01

    Optical Coherence Tomography (OCT) is a non-invasive low coherence interferometry technique that includes several technologies (and the corresponding devices and components), such as illumination and detection, interferometry, scanning, adaptive optics, microscopy and endoscopy. From its large area of applications, we consider in this paper a critical aspect in dentistry - to be investigated with a Time Domain (TD) OCT system. The clinical situation of an edentulous mandible is considered; it can be solved by inserting 2 to 6 implants. On these implants a mesostructure will be manufactured and on it a superstructure is needed. This superstructure can be integral ceramic; in this case materials defects could be trapped inside the ceramic layers and those defects could lead to fractures of the entire superstructure. In this paper we demonstrate that a TD-OCT imaging system has the potential to properly evaluate the presence of the defects inside the ceramic layers and those defects can be fixed before inserting the prosthesis inside the oral cavity. Three integral ceramic superstructures were developed by using a CAD/CAM technology. After the milling, the ceramic layers were applied on the core. All the three samples were evaluated by a TD-OCT system working at 1300 nm. For two of the superstructures evaluated, no defects were found in the most stressed areas. The third superstructure presented four ceramic defects in the mentioned areas. Because of those defects the superstructure may fracture. The integral ceramic prosthesis was send back to the dental laboratory to fix the problems related to the material defects found. Thus, TD-OCT proved to be a valuable method for diagnosing the ceramic defects inside the integral ceramic superstructures in order to prevent fractures at this level.

  12. Choroidal thinning in high myopia measured by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Ikuno Y

    2013-05-01

    Full Text Available Yasushi Ikuno, Satoko Fujimoto, Yukari Jo, Tomoko Asai, Kohji NishidaDepartment of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, JapanPurpose: To investigate the rate of choroidal thinning in highly myopic eyes.Patients and methods: A retrospective observational study of 37 eyes of 26 subjects (nine males and 17 females, mean age 39.6 ± 7.7 years with high myopia but no pathologies who had undergone spectral domain optical coherence tomography and repeated the test 1 year later (1 ± 0.25 year at Osaka University Hospital, Osaka, Japan. Patients older than 50 years with visual acuity worse than 20/40 or with whitish chorioretinal atrophy involving the macula were excluded. Two masked raters measured the choroidal thicknesses (CTs at the foveda, 3 mm superiorly, inferiorly, temporally, and nasally on the images and averaged the values. The second examination was about 365 days after the baseline examination. The CT reduction per year (CTRPY was defined as (CT 1 year after - baseline CT/days between the two examinations × 365. The retinal thicknesses were also investigated.Results: The CTRPY at the fovea was −1.0 ± 22.0 µm (range –50.2 to 98.5 at the fovea, –6.5 ± 24.3 µm (range −65.8 to 90.2 temporally, –0.5 ± 22.3 µm (range –27.1 to 82.5 nasally, –9.7 ± 21.7 µm (range –40.1 to 60.1 superiorly, and –1.4 ± 25.5 µm (range –85.6 to 75.2 inferiorly. There were no significant differences in the CTRPY at each location (P = 0.34. The CT decreased significantly (P < 0.05 only superiorly. The superior CTRPY was negatively correlated with the axial length (P < 0.05. The retinal thickness at the fovea did not change. Stepwise analysis for CTRPY selected axial length (P = 0.04, R2 = 0.13 and age (P = 0.08, R2 = 0.21 as relevant factors.Conclusions: The highly myopic choroid might gradually thin and be affected by many factors. Location and axial length are key factors to regulate the rate of choroidal

  13. [Diagnosis. Radiological study. Ultrasound, computed tomography and magnetic resonance imaging].

    Science.gov (United States)

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Because of its low cost, availability in primary care and ease of interpretation, simple X-ray should be the first-line imaging technique used by family physicians for the diagnosis and/or follow-up of patients with osteoarthritis. Nevertheless, this technique should only be used if there are sound indications and if the results will influence decision-making. Despite the increase of indications in patients with rheumatological disease, the role of ultrasound in patients with osteoarthritis continues to be limited. Computed tomography (CT) is of some -although limited- use in osteoarthritis, especially in the study of complex joints (such as the sacroiliac joint and facet joints). Magnetic resonance imaging (MRI) has represented a major advance in the evaluation of joint cartilage and subchondral bone in patients with osteoarthritis but, because of its high cost and diagnostic-prognostic yield, this technique should only be used in highly selected patients. The indications for ultrasound, CT and MRI in patients with osteoarthritis continue to be limited in primary care and often coincide with situations in which the patient may require hospital referral. Patient safety should be bourne in mind. Patients should be protected from excessive ionizing radiation due to unnecessary repeat X-rays or inadequate views or to requests for tests such as CT, when not indicated. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  14. Photoreceptor layer map using spectral-domain optical coherence tomography.

    Science.gov (United States)

    Lee, Ji Eun; Lim, Dae Won; Bae, Han Yong; Park, Hyun Jin

    2009-12-01

    To develop a novel method for analysis of the photoreceptor layer map (PLM) generated using spectral-domain optical coherence tomography (OCT). OCT scans were obtained from 20 eyes, 10 with macular holes (MH) and 10 with central serous chorioretinopathy (CSC) using the Macular Cube (512 x 128) protocol of the Cirrus HD-OCT (Carl Zeiss). The scanned data were processed using embedded tools of the advanced visualization. A partial thickness OCT fundus image of the photoreceptor layer was generated by setting the region of interest to a 50-microm thick layer that was parallel and adjacent to the retinal pigment epithelium. The resulting image depicted the photoreceptor layer as a map of the reflectivity in OCT. The PLM was compared with fundus photography, auto-fluorescence, tomography, and retinal thickness map. The signal from the photoreceptor layer of every OCT scan in each case was demonstrated as a single image of PLM in a fundus photograph fashion. In PLM images, detachment of the sensory retina is depicted as a hypo-reflective area, which represents the base of MH and serous detachment in CSC. Relative hypo-reflectivity, which was also noted at closed MH and at recently reattached retina in CSC, was associated with reduced signal from the junction between the inner and outer segments of photoreceptors in OCT images. Using PLM, changes in the area of detachment and reflectivity of the photoreceptor layer could be efficiently monitored. The photoreceptor layer can be analyzed as a map using spectral-domain OCT. In the treatment of both MH and CSC, PLM may provide new pathological information about the photoreceptor layer to expand our understanding of these diseases.

  15. Analysis of dental abfractions by optical coherence tomography

    Science.gov (United States)

    Demjan, Enikö; Mărcăuţeanu, Corina; Bratu, Dorin; Sinescu, Cosmin; Negruţiu, Meda; Ionita, Ciprian; Topală, Florin; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian Gh.

    2010-02-01

    Aim and objectives. Abfraction is the pathological loss of cervical hard tooth substance caused by biomechanical overload. High horizontal occlusal forces result in large stress concentrations in the cervical region of the teeth. These stresses may be high enough to cause microfractures in the dental hard tissues, eventually resulting in the loss of cervical enamel and dentin. The present study proposes the microstructural characterization of these cervical lesions by en face optical coherence tomography (eFOCT). Material and methods: 31 extracted bicuspids were investigated using eFOCT. 24 teeth derived from patients with active bruxism and occlusal interferences; they presented deep buccal abfractions and variable degrees of occlusal pathological attrition. The other 7 bicuspids were not exposed to occlusal overload and had a normal morphology of the dental crowns. The dental samples were investigated using an eFOCT system operating at 1300 nm (B-scan at 1 Hz and C-scan mode at 2 Hz). The system has a lateral resolution better than 5 μm and a depth resolution of 9 μm in tissue. OCT images were further compared with micro - computer tomography images. Results. The eFOCT investigation of bicuspids with a normal morphology revealed a homogeneous structure of the buccal cervical enamel. The C-scan and B-scan images obtained from the occlusal overloaded bicuspids visualized the wedge-shaped loss of cervical enamel and damage in the microstructure of the underlaying dentin. The high occlusal forces produced a characteristic pattern of large cracks, which reached the tooth surface. Conclusions: eFOCT is a promising imaging method for dental abfractions and it may offer some insight on the etiological mechanism of these noncarious cervical lesions.

  16. Optical coherence tomography and polarimetry of superficial skin biopsies

    Directory of Open Access Journals (Sweden)

    S. R. Utz

    2015-01-01

    Full Text Available The goal. Of this study was to develop and assess the efficacy of polarization probing of biotissues in vitro. The method is based on the determination of polarization parameters of scattered radiation. Materials and methods. The well-known superficial epidermis stripping method was applied using the Sulfacrylate self-sterile medical adhesive. Small portions of thin layers of the adhesive were applied to slide plates and then to different skin sites. The corneous layer in the normal condition and in case of skin diseases (psoriasis, lichen acuminatus, discoid lupus erythematosus, alopecia, itching and demodectic mange was examined based on the optical coherence tomography (OCT method using the 0CS1300SS device (Thorlabs Inc, USA. Results. The authors obtained pictures visualizing the structural organization of different layers of the epidermis using the superficial epidermis biopsy method in case of lichen acuminatus, hyperkeratosis, itching and other skin diseases. Conclusion. This method ensures non-invasive high-precision measurement of the structure of different layers of the epidermis, which may be useful both for research purposes and practical dermatology.

  17. Optical coherence tomography use in the diagnosis of enamel defects

    Science.gov (United States)

    Al-Azri, Khalifa; Melita, Lucia N.; Strange, Adam P.; Festy, Frederic; Al-Jawad, Maisoon; Cook, Richard; Parekh, Susan; Bozec, Laurent

    2016-03-01

    Molar incisor hypomineralization (MIH) affects the permanent incisors and molars, whose undermineralized matrix is evidenced by lesions ranging from white to yellow/brown opacities to crumbling enamel lesions incapable of withstanding normal occlusal forces and function. Diagnosing the condition involves clinical and radiographic examination of these teeth, with known limitations in determining the depth extent of the enamel defects in particular. Optical coherence tomography (OCT) is an emerging hard and soft tissue imaging technique, which was investigated as a new potential diagnostic method in dentistry. A comparison between the diagnostic potential of the conventional methods and OCT was conducted. Compared to conventional imaging methods, OCT gave more information on the structure of the enamel defects as well as the depth extent of the defects into the enamel structure. Different types of enamel defects were compared, each type presenting a unique identifiable pattern when imaged using OCT. Additionally, advanced methods of OCT image analysis including backscattered light intensity profile analysis and enface reconstruction were performed. Both methods confirmed the potential of OCT in enamel defects diagnosis. In conclusion, OCT imaging enabled the identification of the type of enamel defect and the determination of the extent of the enamel defects in MIH with the advantage of being a radiation free diagnostic technique.

  18. Evaluation of fingerprint deformation using optical coherence tomography

    Science.gov (United States)

    Gutierrez da Costa, Henrique S.; Maxey, Jessica R.; Silva, Luciano; Ellerbee, Audrey K.

    2014-02-01

    Biometric identification systems have important applications to privacy and security. The most widely used of these, print identification, is based on imaging patterns present in the fingers, hands and feet that are formed by the ridges, valleys and pores of the skin. Most modern print sensors acquire images of the finger when pressed against a sensor surface. Unfortunately, this pressure may result in deformations, characterized by changes in the sizes and relative distances of the print patterns, and such changes have been shown to negatively affect the performance of fingerprint identification algorithms. Optical coherence tomography (OCT) is a novel imaging technique that is capable of imaging the subsurface of biological tissue. Hence, OCT may be used to obtain images of subdermal skin structures from which one can extract an internal fingerprint. The internal fingerprint is very similar in structure to the commonly used external fingerprint and is of increasing interest in investigations of identify fraud. We proposed and tested metrics based on measurements calculated from external and internal fingerprints to evaluate the amount of deformation of the skin. Such metrics were used to test hypotheses about the differences of deformation between the internal and external images, variations with the type of finger and location inside the fingerprint.

  19. Spectral Domain Optical Coherence Tomography Findings in Posterior Microphthalmia

    Directory of Open Access Journals (Sweden)

    Emine Tınkır Kayıtmazbatır

    2014-05-01

    Full Text Available The retinal spectral domain optical coherence tomography (SD-OCT findings of two posterior microphthalmia cases are presented in this case report. For this purpose, the findings of two siblings aged five and seven years who presented to our clinic with the complain of far-sightedness and high hypermetropia were evaluated. Both cases diagnosed to have posterior microphthalmia demonstrated normal biomicroscopic anterior segment examination and gonioscopy findings and the axial lengths were measured to be shorter than 17mm. The SD-OCT analysis of papillomacular folds detected in fundus examination revealed contribution of only neurosensorial retina. Beneath the retinal fold, we observed bilateral cysts in the intraretinal area in one of the cases and a triangle-shaped hyporeflective space with an apex corresponding to that of the retinal fold in the subretinal area in both cases. SD-OCT is an adjunctive imaging tool for diagnosis and follow-up of degenerative changes in posterior microphthalmia. These changes may be also important for visual prognosis. (Turk J Ophthalmol 2014; 44: 240-2

  20. Imaging Cutaneous T-Cell Lymphoma with Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hans Christian Ring

    2012-07-01

    Full Text Available Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL using optical coherence tomography (OCT. Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT-scanned for comparison, but not biopsied. The OCT image and the histological image were compared. Results: The OCT images illustrated a thickened and hyperreflective stratum corneum. OCT also demonstrated several elongated hyporeflective structures in the dermis. The largest structure was measured to have a width of 0.13 mm. A good immediate correlation was found between histology and OCT imaging of the sample. Conclusion: The aetiology of the elongated structures is thought to be lymphomatous infiltrates. Similar findings have been described in ocular lymphoma and may therefore be an important characteristic of cutaneous lymphoma. It may further be speculated that the differences in OCT images may reflect the biological behaviour of the infiltrate. This observation therefore suggests that OCT imaging may be a relevant tool for the in vivo investigation of mycosis fungoides and other CTCLs, but in order to verify these observed patterns in OCT imaging, further investigations will be required.

  1. Evaluating tear clearance rate with optical coherence tomography.

    Science.gov (United States)

    Garaszczuk, Izabela K; Mousavi, Maryam; Cervino Exposito, Alejandro; Bartuzel, Maciej M; Montes-Micó, Robert; Iskander, D Robert

    2018-02-01

    To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality. TCR was classified as the percentage decrease of subject's inferior tear meniscus height 30s after instillation of 5μl 0.9% saline solution. Fifty subjects (32F and 18M) aged (mean±standard deviation) 25.5±4.3 years volunteered for the study. It consisted of a review of medical history, Ocular Surface Disease Index (OSDI) questionnaire, tear film osmolarity measurements, slit lamp examination and TCR estimation based on dynamic measurements of the lower tear meniscus with OCT. Estimates of TCR were contrasted against subject age and tear film measures commonly used for dry eye diagnosis, which includes OSDI score, fluorescein tear film break-up time (FBUT), tear meniscus height (TMH), blinking frequency, tear film osmolarity and corneal staining. The group mean TCR was 29±13% and 36±19% respectively after 30 and 60s margin after saline solution instillation. Statistically significant correlations were found between TCR and FBUT (r 2 =0.319, placrimal functional unit. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  2. Optical coherence tomography for the diagnosis of human otitis media

    Science.gov (United States)

    Cho, Nam Hyun; Jung, Unsang; Jang, Jeong Hun; Jung, Woonggyu; Kim, Jeehyun; Lee, Sang Heun; Boppart, Stephen A.

    2013-05-01

    We report the application of Optical Coherence Tomography (OCT) to various types of human cases of otitis media (OM). Whereas conventional diagnostic modalities for OM, including standard and pneumatic otoscopy, are limited to visualizing the surface information of the tympanic membrane (TM), OCT is able to effectively reveal the depth-resolved microstructural below the TM with a very high spatial resolution. With the potential advantage of using OCT for diagnosing different types of OM, we examined in-vivo the use of 840 nm wavelength, and OCT spectral domain OCT (SDOCT) techniques, in several human cases including normal ears, and ears with adhesive and effusion types of OM. Peculiar positions were identified in two-dimensional OCT images of abnormal TMs compared to images of a normal TM. Analysis of A-scan (axial depth-scans) data from these positions could successfully identify unique patterns for different constituents within effusions. These OCT images may not only be used for constructing a database for the diagnosis and classification of OM, but they may also demonstrate the feasibility and advantages for upgrading the current otoscopy techniques.

  3. Implementation of an Optical Coherence Tomography system for painting characterization

    International Nuclear Information System (INIS)

    Kashyap, Hannah U. K. S.; Mota, Claudia C. B. O.; Kyotoku, Bernardo B. C.; Gomes, Anderson S. L.; Santos-Filho, Plinio B.

    2009-01-01

    Optical Coherence Tomography (OCT) is a new but well established imaging technique for medical diagnosis, which can produce two- or three-dimensional images of bio-tissues with a few μm spatial resolution. Its potential as a non-invasive tool for art conservation of paintings and other objects has been realized recently. In this work, we report the implementation of two OCT systems applied to painting characterization. One system operates in the so-called spectral domain, with a central wavelength of 840 nm and axial resolution of 10 μm. The second system has its central wavelength at 1280 nm, with spatial resolution of 20 μm, and operates in the time domain. Both systems are independently controlled and have imaging software developed in-house using Lab View. Using both systems, a 15 years old acrylic portrait has been analyzed, where the paint layers, light and dark colors, and the cotton treads of the canvas could be identified. (Author)

  4. Polarization sensitive optical coherence tomography in equine bone

    Science.gov (United States)

    Jacobs, J. W.; Matcher, S. J.

    2009-02-01

    Optical coherence tomography (OCT) has been used to image equine bone samples. OCT and polarization sensitive OCT (PS-OCT) images of equine bone samples, before and after demineralization, are presented. Using a novel approach, taking a series of images at different angles of illumination, the polar angle and true birefringence of collagen within the tissue is determined, at one site in the sample. The images were taken before and after the bones were passed through a demineralization process. The images show an improvement in depth penetration after demineralization allowing better visualization of the internal structure of the bone and the optical orientation of the collagen. A quantitative measurement of true birefringence has been made of the bone; true birefringence was shown to be 1.9x10-3 before demineralization increasing to 2.7x10-3 after demineralization. However, determined collagen fiber orientation remains the same before and after demineralization. The study of bone is extensive within the field of tissue engineering where an understanding of the internal structures is essential. OCT in bone, and improved depth penetration through demineralization, offers a useful approach to bone analysis.

  5. The potential of optical coherence tomography for diagnosing meniscal pathology

    Science.gov (United States)

    Hang-Yin Ling, Carrie; Pozzi, Antonio; Thieman, Kelley M.; Tonks, Catherine A.; Guo, Shuguang; Xie, Huikai; Horodyski, MaryBeth

    2010-04-01

    Meniscal tears are often associated with anterior cruciate ligament (ACL) injury and may lead to pain and discomfort in humans. Maximal preservation of meniscal tissue is highly desirable to mitigate the progression of osteoarthritis. Guidelines of which meniscal tears are amenable to repair and what part of damaged tissues should be removed are elusive and lacking consensus. Images of microstructural changes in meniscus would potentially guide the surgeons to manage the meniscal tears better, but the resolution of current diagnostic techniques is limited for this application. In this study, we demonstrated the feasibility of using optical coherence tomography (OCT) for the diagnosis of meniscal pathology. Torn medial menisci were collected from dogs with ACL insufficiency. The torn meniscus was divided into three tissue samples and scanned by OCT and scanning electron microscopy (SEM). OCT and SEM images of torn menisci were compared. Each sample was evaluated for gross and microstructural abnormalities and reduction or loss of birefringence from the OCT images. The abnormalities detected with OCT were described for each type of tear. OCT holds promise in non-destructive and fast assessment of microstructural changes and tissue birefringence of meniscal tears. Future development of intraoperative OCT may help surgeons in the decision making of meniscal treatment.

  6. The potential of optical coherence tomography for diagnosing meniscal pathology

    International Nuclear Information System (INIS)

    Ling, Carrie Hang-Yin; Horodyski, MaryBeth; Pozzi, Antonio; Thieman, Kelley M; Tonks, Catherine A; Guo, Shuguang; Xie, Huikai

    2010-01-01

    Meniscal tears are often associated with anterior cruciate ligament (ACL) injury and may lead to pain and discomfort in humans. Maximal preservation of meniscal tissue is highly desirable to mitigate the progression of osteoarthritis. Guidelines of which meniscal tears are amenable to repair and what part of damaged tissues should be removed are elusive and lacking consensus. Images of microstructural changes in meniscus would potentially guide the surgeons to manage the meniscal tears better, but the resolution of current diagnostic techniques is limited for this application. In this study, we demonstrated the feasibility of using optical coherence tomography (OCT) for the diagnosis of meniscal pathology. Torn medial menisci were collected from dogs with ACL insufficiency. The torn meniscus was divided into three tissue samples and scanned by OCT and scanning electron microscopy (SEM). OCT and SEM images of torn menisci were compared. Each sample was evaluated for gross and microstructural abnormalities and reduction or loss of birefringence from the OCT images. The abnormalities detected with OCT were described for each type of tear. OCT holds promise in non-destructive and fast assessment of microstructural changes and tissue birefringence of meniscal tears. Future development of intraoperative OCT may help surgeons in the decision making of meniscal treatment

  7. Retinal Imaging of Infants on Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Anand Vinekar

    2015-01-01

    Full Text Available Spectral domain coherence tomography (SD OCT has become an important tool in the management of pediatric retinal diseases. It is a noncontact imaging device that provides detailed assessment of the microanatomy and pathology of the infant retina with a short acquisition time allowing office examination without the requirement of anesthesia. Our understanding of the development and maturation of the infant fovea has been enhanced by SD OCT allowing an in vivo assessment that correlates with histopathology. This has helped us understand the critical correlation of foveal development with visual potential in the first year of life and beyond. In this review, we summarize the recent literature on the clinical applications of SD OCT in studying the pathoanatomy of the infant macula, its ability to detect subclinical features, and its correlation with disease and vision. Retinopathy of prematurity and macular edema have been discussed in detail. The review also summarizes the current status of SD OCT in other infant retinal conditions, imaging the optic nerve, the choroid, and the retinal nerve fibre in infants and children, and suggests future areas of research.

  8. Optical coherence tomography: imaging architect for dermal microdialysis in psoriasis

    Science.gov (United States)

    O'Connell, M.-L.; O'Connor, W.; Ramsay, B.; Guihen, E.; Ho, W. L.; Leahy, M. J.

    2011-03-01

    Optical coherence tomography (OCT) has been used as part of a ground breaking translational study to shed some light on one of the worlds most prevalent autoimmune diseases; psoriasis. The work successfully integrates the fields of optical imaging, biochemistry and dermatology in conducting a dermal microdialysis (DMD) trial for quantitative histamine assessment amongst a group of psoriasis sufferers. The DMD process involves temporary insertion of microscopic hollow tubes into a layer of skin to measure the levels of histamine and other important biological molecules in psoriasis. For comparison purposes, DMD catheters were implanted into healthy, peri-lesional and lesional skin regions. The catheters' entry and exit points and their precise locations in the epidermal layer of the skin were confirmed using OCT thus obtaining high resolution, wide-field images of the affected skin as well as catheter placement whilst local microdialysis enabled a tissue chemistry profile to be obtained from these three skin regions including histamine, a local immune system activator known to contribute towards itch and inflammation. Together these tools offer a synergistic approach in the clinical assessment of the disease. In addition, OCT delivered a non-invasive and rapid method for analyzing the affected skin architecture.

  9. Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography

    Science.gov (United States)

    Wang, Tianshi; Pfeiffer, Tom; Regar, Evelyn; Wieser, Wolfgang; van Beusekom, Heleen; Lancee, Charles T.; Springeling, Geert; Krabbendam, Ilona; van der Steen, Antonius F.W.; Huber, Robert; van Soest, Gijs

    2015-01-01

    Cardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging system that we called “Heartbeat OCT”, combining a fast Fourier Domain Mode Locked laser, fast pullback, and a micromotor actuated catheter, designed to examine a coronary vessel in less than one cardiac cycle. We acquired in vivo data sets of two coronary arteries in a porcine heart with both Heartbeat OCT, working at 2.88 MHz A-line rate, 4000 frames/s and 100 mm/s pullback speed, and with a commercial system. The in vivo results show that Heartbeat OCT provides faithfully rendered, motion-artifact free, fully sampled vessel wall architecture, unlike the conventional IV-OCT data. We present the Heartbeat OCT system in full technical detail and discuss the steps needed for clinical translation of the technology. PMID:26713214

  10. A Micromotor Catheter for Intravascular Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Tianshi Wang

    2015-03-01

    Full Text Available We have developed a new form of intravascular optical coherence tomography (IV-OCT that allows the extremely fast acquisition of high-resolution images of the coronary arteries. This process leads to much better image quality by eliminating cardiac motion artefacts and undersampling. It relies on a catheter that incorporates a synchronous micromotor with a diameter of 1.0 mm and a rotational speed of up to 5600 revolutions per second, enabling an IV-OCT frame rate of 5.6 kHz. This speed is matched by a wavelength-swept laser that generates up to 2.8 million image lines per second. With this setup, our team achieved IV-OCT imaging of up to 5600 frames per second (fps in vitro and 4000 fps in vivo, deployed at a 100 mm·s−1 pullback velocity. The imaging session is triggered by the electrocardiogram of the subject, and can scan a coronary artery in the phase of the heartbeat where the heart is at rest, providing a name for this new technology: the “Heartbeat OCT.”

  11. Ultrahigh speed endoscopic optical coherence tomography for gastroenterology.

    Science.gov (United States)

    Tsai, Tsung-Han; Lee, Hsiang-Chieh; Ahsen, Osman O; Liang, Kaicheng; Giacomelli, Michael G; Potsaid, Benjamin M; Tao, Yuankai K; Jayaraman, Vijaysekhar; Figueiredo, Marisa; Huang, Qin; Cable, Alex E; Fujimoto, James; Mashimo, Hiroshi

    2014-12-01

    We describe an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor imaging catheter. The system had a 600 kHz axial scan rate and 8 µm axial resolution in tissue. Imaging was performed with a 3.2 mm diameter imaging catheter at 400 frames per second with a 12 µm spot size. Three-dimensional OCT (3D-OCT) imaging was performed in patients with a cross section of pathologies undergoing upper and lower endoscopy. The use of distally actuated imaging catheters enabled OCT imaging with more flexibility, such as volumetric imaging in the small intestine and the assessment of hiatal hernia using retroflex imaging. The high rotational scanning stability of the micromotor enabled 3D volumetric imaging with micron scale volumetric accuracy for both en face OCT and cross-sectional imaging, as well as OCT angiography (OCTA) for 3D visualization of subsurface microvasculature. The ability to perform both structural and functional 3D OCT imaging in the GI tract with microscopic accuracy should enable a wide range of studies and enhance the sensitivity and specificity of OCT for detecting pathology.

  12. Three dimensional optical coherence tomography imaging: advantages and advances.

    Science.gov (United States)

    Gabriele, Michelle L; Wollstein, Gadi; Ishikawa, Hiroshi; Xu, Juan; Kim, Jongsick; Kagemann, Larry; Folio, Lindsey S; Schuman, Joel S

    2010-11-01

    Three dimensional (3D) ophthalmic imaging using optical coherence tomography (OCT) has revolutionized assessment of the eye, the retina in particular. Recent technological improvements have made the acquisition of 3D-OCT datasets feasible. However, while volumetric data can improve disease diagnosis and follow-up, novel image analysis techniques are now necessary in order to process the dense 3D-OCT dataset. Fundamental software improvements include methods for correcting subject eye motion, segmenting structures or volumes of interest, extracting relevant data post hoc and signal averaging to improve delineation of retinal layers. In addition, innovative methods for image display, such as C-mode sectioning, provide a unique viewing perspective and may improve interpretation of OCT images of pathologic structures. While all of these methods are being developed, most remain in an immature state. This review describes the current status of 3D-OCT scanning and interpretation, and discusses the need for standardization of clinical protocols as well as the potential benefits of 3D-OCT scanning that could come when software methods for fully exploiting these rich datasets are available clinically. The implications of new image analysis approaches include improved reproducibility of measurements garnered from 3D-OCT, which may then help improve disease discrimination and progression detection. In addition, 3D-OCT offers the potential for preoperative surgical planning and intraoperative surgical guidance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Benefits of optical coherence tomography for imaging of skin diseases

    Directory of Open Access Journals (Sweden)

    Utz S.R.

    2015-09-01

    Full Text Available Aim: working out the methods of visualization of information obtained during optical coherent tomography in normal skin and in series of inflammatory disorders. Materials and Methods. OCS1300SS (made in Thorlabs, USA was used in which the source of emission of radiation was a super-luminiscent diode with mean wavelength of 1325 nm. 12 patients with different skin conditions and 5 virtually healthy volunteers were examined with ОСТ procedure in OPD and IPD settings. High resolution USG numerical system DUB (TPM GmbH, Germany was used for comparative USG assessment. Results. ОСТ demonstrated considerably more detailed picture of the objects scanned compared to USG investigation. Image obtained with the help of ОСТ contains vital information about sizes of macro-morphological elements, status of vascular elements and their density in different depths of the skin. Conclusion. Additional results obtained from ОСТ of the skin lesions in plane section improves attraction for ОСТ in practical dermatology.

  14. Optical coherence tomography detection of subclinical traumatic cartilage injury.

    Science.gov (United States)

    Bear, David M; Szczodry, Michal; Kramer, Scott; Coyle, Christian H; Smolinski, Patrick; Chu, Constance R

    2010-09-01

    Posttraumatic arthritis is a major cause of disability. Current clinical imaging modalities are unable to reliably evaluate articular cartilage damage before surface breakdown, when potentially reversible changes are occurring. Optical coherence tomography (OCT) is a nondestructive imaging technology that can detect degenerative changes in articular cartilage with an intact surface. This study tests the hypothesis that OCT detects acute articular cartilage injury after impact at energy levels resulting in chondrocyte death and microstructural changes, but insufficient to produce macroscopic surface damage. Bovine osteochondral cores underwent OCT imaging and were divided into a control with no impact or were subjected to low (0.175 J) or moderate (0.35 J) energy impact. Cores were reimaged with OCT after impact and the OCT signal intensity quantified. A ratio of the superficial to deep layer intensities was calculated and compared before and after impact. Chondrocyte viability was determined 1 day after impact followed by histology and polarized microscopy. Macroscopic changes to the articular surface were not observed after low and moderate impact. The OCT signal intensity ratio demonstrated a 27% increase (P = 0.006) after low impact and a 38% increase (P = 0.001) after moderate impact. Cell death increased by 150% (P death and microscopic matrix damage. This finding supports the use of OCT to detect microstructural subsurface cartilage damage that is poorly visualized with conventional imaging.

  15. Monte Carlo modeling of human tooth optical coherence tomography imaging

    International Nuclear Information System (INIS)

    Shi, Boya; Meng, Zhuo; Wang, Longzhi; Liu, Tiegen

    2013-01-01

    We present a Monte Carlo model for optical coherence tomography (OCT) imaging of human tooth. The model is implemented by combining the simulation of a Gaussian beam with simulation for photon propagation in a two-layer human tooth model with non-parallel surfaces through a Monte Carlo method. The geometry and the optical parameters of the human tooth model are chosen on the basis of the experimental OCT images. The results show that the simulated OCT images are qualitatively consistent with the experimental ones. Using the model, we demonstrate the following: firstly, two types of photons contribute to the information of morphological features and noise in the OCT image of a human tooth, respectively. Secondly, the critical imaging depth of the tooth model is obtained, and it is found to decrease significantly with increasing mineral loss, simulated as different enamel scattering coefficients. Finally, the best focus position is located below and close to the dental surface by analysis of the effect of focus positions on the OCT signal and critical imaging depth. We anticipate that this modeling will become a powerful and accurate tool for a preliminary numerical study of the OCT technique on diseases of dental hard tissue in human teeth. (paper)

  16. Volumetric full-range magnetomotive optical coherence tomography

    Science.gov (United States)

    Ahmad, Adeel; Kim, Jongsik; Shemonski, Nathan D.; Marjanovic, Marina; Boppart, Stephen A.

    2014-01-01

    Abstract. Magnetomotive optical coherence tomography (MM-OCT) can be utilized to spatially localize the presence of magnetic particles within tissues or organs. These magnetic particle-containing regions are detected by using the capability of OCT to measure small-scale displacements induced by the activation of an external electromagnet coil typically driven by a harmonic excitation signal. The constraints imposed by the scanning schemes employed and tissue viscoelastic properties limit the speed at which conventional MM-OCT data can be acquired. Realizing that electromagnet coils can be designed to exert MM force on relatively large tissue volumes (comparable or larger than typical OCT imaging fields of view), we show that an order-of-magnitude improvement in three-dimensional (3-D) MM-OCT imaging speed can be achieved by rapid acquisition of a volumetric scan during the activation of the coil. Furthermore, we show volumetric (3-D) MM-OCT imaging over a large imaging depth range by combining this volumetric scan scheme with full-range OCT. Results with tissue equivalent phantoms and a biological tissue are shown to demonstrate this technique. PMID:25472770

  17. Spectroscopic Doppler analysis for visible-light optical coherence tomography

    Science.gov (United States)

    Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

    2017-12-01

    Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

  18. Optical coherence tomography – current and future applications

    Science.gov (United States)

    Adhi, Mehreen; Duker, Jay S.

    2013-01-01

    Purpose of review Optical coherence tomography (OCT) has revolutionized the clinical practice of ophthalmology. It is a noninvasive imaging technique that provides high-resolution, cross-sectional images of the retina, retinal nerve fiber layer and the optic nerve head. This review discusses the present applications of the commercially available spectral-domain OCT (SD-OCT) systems in the diagnosis and management of retinal diseases, with particular emphasis on choroidal imaging. Future directions of OCT technology and their potential clinical uses are discussed. Recent findings Analysis of the choroidal thickness in healthy eyes and disease states such as age-related macular degeneration, central serous chorioretinopathy, diabetic retinopathy and inherited retinal dystrophies has been successfully achieved using SD-OCT devices with software improvements. Future OCT innovations such as longer-wavelength OCT systems including the swept-source technology, along with Doppler OCT and en-face imaging, may improve the detection of subtle microstructural changes in chorioretinal diseases by improving imaging of the choroid. Summary Advances in OCT technology provide for better understanding of pathogenesis, improved monitoring of progression and assistance in quantifying response to treatment modalities in diseases of the posterior segment of the eye. Further improvements in both hardware and software technologies should further advance the clinician’s ability to assess and manage chorioretinal diseases. PMID:23429598

  19. Differentiating functional brain regions using optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Gil, Daniel A.; Bow, Hansen C.; Shen, Jin-H.; Joos, Karen M.; Skala, Melissa C.

    2017-02-01

    The human brain is made up of functional regions governing movement, sensation, language, and cognition. Unintentional injury during neurosurgery can result in significant neurological deficits and morbidity. The current standard for localizing function to brain tissue during surgery, intraoperative electrical stimulation or recording, significantly increases the risk, time, and cost of the procedure. There is a need for a fast, cost-effective, and high-resolution intraoperative technique that can avoid damage to functional brain regions. We propose that optical coherence tomography (OCT) can fill this niche by imaging differences in the cellular composition and organization of functional brain areas. We hypothesized this would manifest as differences in the attenuation coefficient measured using OCT. Five functional regions (prefrontal, somatosensory, auditory, visual, and cerebellum) were imaged in ex vivo porcine brains (n=3), a model chosen due to a similar white/gray matter ratio as human brains. The attenuation coefficient was calculated using a depth-resolved model and quantitatively validated with Intralipid phantoms across a physiological range of attenuation coefficients (absolute difference Nissl-stained histology will be used to validate our results and correlate OCT-measured attenuation coefficients to neuronal density. Additional development and validation of OCT algorithms to discriminate brain regions are planned to improve the safety and efficacy of neurosurgical procedures such as biopsy, electrode placement, and tissue resection.

  20. Optical coherence tomography for nondestructive evaluation of fuel rod degradation

    International Nuclear Information System (INIS)

    Renshaw, Jeremy B.; Jenkins, Thomas P.; Buckner, Benjamin D.; Friend, Brian

    2015-01-01

    Nuclear power plants regularly inspect fuel rods to ensure safe and reliable operation. Excessive corrosion can cause fuel failures which can have significant repercussions for the plant, including impacts on plant operation, worker exposure to radiation, and the plant's INPO rating. While plants typically inspect for fuel rod corrosion using eddy current techniques, these techniques have known issues with reliability in the presence of tenacious, ferromagnetic crud layers that can deposit during operation, and the nondestructive evaluation (NDE) inspection results can often be in error by a factor of 2 or 3. For this reason, alternative measurement techniques, such as Optical Coherence Tomography (OCT), have been evaluated that are not sensitive to the ferromagnetic nature of the crud. This paper demonstrates that OCT has significant potential to characterize the thickness of crud layers that can deposit on the surfaces of fuel rods during operation. Physical trials have been performed on simulated crud samples, and the resulting data show an apparent correlation between the crud layer thickness and the OCT signal

  1. Optical coherence tomography for nondestructive evaluation of fuel rod degradation

    Energy Technology Data Exchange (ETDEWEB)

    Renshaw, Jeremy B., E-mail: jrenshaw@epri.com [Electric Power Research Institute, 1300 West WT Harris Blvd., Charlotte, NC 28262 (United States); Jenkins, Thomas P., E-mail: tjenkins@metrolaserinc.com; Buckner, Benjamin D., E-mail: tjenkins@metrolaserinc.com [MetroLaser, Inc., 22941 Mill Creek Drive, Laguna Hills, CA 92653 (United States); Friend, Brian [AREVA, Inc., 3315 Old Forest Road, Lynchburg, VA 24501 (United States)

    2015-03-31

    Nuclear power plants regularly inspect fuel rods to ensure safe and reliable operation. Excessive corrosion can cause fuel failures which can have significant repercussions for the plant, including impacts on plant operation, worker exposure to radiation, and the plant's INPO rating. While plants typically inspect for fuel rod corrosion using eddy current techniques, these techniques have known issues with reliability in the presence of tenacious, ferromagnetic crud layers that can deposit during operation, and the nondestructive evaluation (NDE) inspection results can often be in error by a factor of 2 or 3. For this reason, alternative measurement techniques, such as Optical Coherence Tomography (OCT), have been evaluated that are not sensitive to the ferromagnetic nature of the crud. This paper demonstrates that OCT has significant potential to characterize the thickness of crud layers that can deposit on the surfaces of fuel rods during operation. Physical trials have been performed on simulated crud samples, and the resulting data show an apparent correlation between the crud layer thickness and the OCT signal.

  2. Determination of dental decay rates with optical coherence tomography

    International Nuclear Information System (INIS)

    Freitas, A Z; Zezell, D M; Vieira, N D Jr.; Mayer, M P A; Ribeiro, A C; Gomes, A S L

    2009-01-01

    We report the use of optical coherence tomography (OCT) to detect and quantify demineralization process induced by S. mutans biofilm in third molars human teeth. Artificial lesions were induced by a S. mutans microbiological culture and the samples (N = 50) were divided into groups according to the demineralization time: 3, 5, 7, 9, and 11 days. The OCT system was implemented using a light source delivering an average power of 96 μW in the sample arm, and spectral characteristics allowing 23 μm of axial resolution. The images were produced with lateral scans step of 10 μm and analyzed individually. As a result of the evaluation of theses images, lesion depth was calculated as function of demineralization time. The depth of the lesion in the root dentine increased from 70 μm to 230 μm (corrected by the enamel refraction index, 1.62 @ 856 nm), depending of exposure time. The lesion depth in root dentine was correlated to demineralization time, showing that it follows a geometrical progression like a bacteria growth law

  3. Three-dimensional calibration targets for optical coherence tomography

    Science.gov (United States)

    Gabriele Sandrian, Michelle; Tomlins, Pete; Woolliams, Peter; Rasakanthan, Janarthanan; Lee, Graham C.; Yang, Anna; Považay, Boris; Alex, Aneesh; Sugden, Kate; Drexler, Wolfgang

    2012-03-01

    The recent expansion of clinical applications for optical coherence tomography (OCT) is driving the development of approaches for consistent image acquisition. There is a simultaneous need for time-stable, easy-to-use imaging targets for calibration and standardization of OCT devices. We present calibration targets consisting of three-dimensional structures etched into nanoparticle-embedded resin. Spherical iron oxide nanoparticles with a predominant particle diameter of 400 nm were homogeneously dispersed in a two part polyurethane resin and allowed to harden overnight. These samples were then etched using a precision micromachining femtosecond laser with a center wavelength of 1026 nm, 100kHz repetition rate and 450 fs pulse duration. A series of lines in depth were etched, varying the percentage of inscription energy and speed of the translation stage moving the target with respect to the laser. Samples were imaged with a dual wavelength spectral-domain OCT system (λ=800nm, ▵λ~180nm, and λ=1325nm, ▵λ~100nm) and point-spread function of nanoparticles within the target was measured.

  4. Optical Coherence Tomography Findings in Patients With Stent Thrombosis.

    Science.gov (United States)

    Cuesta, Javier; Rivero, Fernando; Bastante, Teresa; García-Guimaraes, Marcos; Antuña, Paula; Alvarado, Teresa; Navarrete, Gonzalo; Benedicto, Amparo; Alfonso, Fernando

    2017-12-01

    Stent thrombosis (ST) is a rare but potentially serious complication. Optical coherence tomography (OCT) provides high-resolution images and additional information to angiography in the study of this event. Prospective study of patients with ST undergoing reintervention with OCT imaging. The study included a total of 40 consecutive patients with ST. Mean age was 69 ± 13 years and 83% were male. Early ST (≤ 30 days) was observed in 16 patients and late ST (> 30 days) in 24 patients. Stent thrombosis occurred in 17 bare-metal stents and 23 drug-eluting stents. In 34 patients (85%), adequate OCT images were obtained at the time of the ST. The predominant mechanism in early ST was stent malapposition (39%). In late ST, high frequencies of uncovered (46%) and malapposed struts (17%) were observed, especially in patients with drug-eluting stents. Furthermore, the presence of neoatherosclerosis was very high (67%) in patients with late ST. After intervention, improvements were observed in malapposition length and the amount of residual thrombus. OCT allows identification of the underlying mechanisms potentially involved in ST. This imaging modality is helpful in guiding reintervention in these patients, which improves the area and length of malapposition, as well as the maximal residual thrombus area. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Optical coherence tomography in guided surgery of GI cancer

    Science.gov (United States)

    Zagaynova, Elena V.; Abelevich, Alexander I.; Zagaynov, Vladimir E.; Gladkova, Natalia D.; Denisenko, Arkady N.; Feldchtein, Felix I.; Snopova, Ludmila B.; Kutis, Irina S.

    2005-04-01

    Optical Coherence Tomography (OCT) is a new high spatial resolution, real-time optical imaging modality, known from prior pilot studies for its high sensitivity to invasive cancer. We reported our results in an OCT feasibility study for accurate determination of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. The OCT study enrolled 19 patients with rectal adenocarcinoma and 24 patients with distal esophageal carcinoma (14 squamous cell carcinomas, 10 adenocarcinomas). During pre-surgery planning endoscopy we performed in vivo OCT imaging of the tumor border at four dial clock axes (12, 3, 6 and 9 o"clock). The OCT border then was marked by an electrocoagulator, or by a methylene blue tattoo. A cold biopsy (from the esophagus) was performed at visual and OCT borders and compared with visual and OCT readings. 27 post-surgery excised specimens were analyzed. OCT borders matched the histopathology in 94% cases in the rectum and 83.3% in the esophagus. In the cases of a mismatch between the OCT and histology borders, a deep tumor invasion occurred in the muscle layer (esophagus, rectum). Because of its high sensitivity to mucosal cancer, OCT can be used for pre-surgery planning and surgery guidance of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. However, deep invasion in the rectum or esophageal wall has to be controlled by alternative diagnostic modalities.

  6. Cystoid macular edema diagnosed with optical coherent tomography in patients operated on from cataract

    International Nuclear Information System (INIS)

    Diaz Arencibia, Omar; Rodriguez Rodriguez, Beatriz; Eguias Martinez, Frank; Alemany Rubio, Ernesto; Guerra, Roberto Alejandro

    2009-01-01

    Refers frequency of cystoid macular edema diagnosed with optical coherence tomography in patients operated on from senile cataract at 'Ramon Pando Ferrer' Cuban Institute of Ophthalmology in the period from December 2006 to February 2007

  7. Fundus autofluorescence and optical coherence tomography findings in thiamine responsive megaloblastic anemia.

    Science.gov (United States)

    Ach, Thomas; Kardorff, Rüdiger; Rohrschneider, Klaus

    2015-01-01

    To report ophthalmologic fundus autofluorescence and spectral domain optical coherence tomography findings in a patient with thiamine responsive megaloblastic anemia (TRMA). A 13-year-old girl with genetically proven TRMA was ophthalmologically (visual acuity, funduscopy, perimetry, electroretinogram) followed up over >5 years. Fundus imaging also included autofluorescence and spectral domain optical coherence tomography. During a 5-year follow-up, visual acuity and visual field decreased, despite a special TRMA diet. Funduscopy revealed bull's eye appearance, whereas fundus autofluorescence showed central and peripheral hyperfluorescence and perifoveal hypofluorescence. Spectral domain optical coherence tomography revealed affected inner segment ellipsoid band and irregularities in the retinal pigment epithelium and choroidea. Autofluorescence and spectral domain optical coherence tomography findings in a patient with TRMA show retinitis pigmentosa-like retina, retinal pigment epithelium, and choroid alterations. These findings might progress even under special TRMA diet, indispensable to life. Ophthalmologist should consider TRMA in patients with deafness and ophthalmologic disorders.

  8. Spectral domain optical coherence tomography findings in tamoxifen retinopathy--a case report.

    Science.gov (United States)

    Nair, Sandhya Narayanan; Anantharaman, Giridhar; Gopalakrishnan, Mahesh; Vyas, Jyothiprakash

    2013-01-01

    To report spectral domain optical coherence tomography findings in a case of typical tamoxifen retinopathy. In this observational case report, a patient with tamoxifen retinopathy was imaged with spectral domain optical coherence tomography and fundus auto fluorescence. Spectral domain optical coherence tomography showed numerous hyperreflective spots within the retina, mainly in the inner retinal layers in both the eyes. The external limiting membrane, the Inner Segment-Outer Segment junction, and the photoreceptors were not discernable at the fovea in the right eye. In the left eye, there was foveal atrophy with total loss of photoreceptors. The autofluorescent images showed macular hypofluorescence with foveal hyperfluorescence. Spectral domain optical coherence tomography demonstrated abnormalities in the outer retinal layers in tamoxifen retinopathy. There were also characteristic alterations in the autofluorescence pattern at the macula in tamoxifen retinopathy.

  9. Mechanisms of Very Late Drug-Eluting Stent Thrombosis Assessed by Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Taniwaki, Masanori; Radu, Maria D; Zaugg, Serge

    2016-01-01

    BACKGROUND: The pathomechanisms underlying very late stent thrombosis (VLST) after implantation of drug-eluting stents (DES) are incompletely understood. Using optical coherence tomography, we investigated potential causes of this adverse event. METHODS AND RESULTS: Between August 2010 and Decemb...

  10. Damage invariant and high security acquisition of the internal fingerprint using optical coherence tomography

    CSIR Research Space (South Africa)

    Darlow, Luke N

    2016-11-01

    Full Text Available representation they offer. Using an emerging fingerprint acquisition technology – optical coherence tomography – to access an internal fingerprint under the skin surface, this paper serves to address two limitations of conventional scanners: fingertip skin damage...

  11. Characterization of dynamic physiology of the bladder by optical coherence tomography

    Science.gov (United States)

    Yuan, Zhijia; Keng, Kerri; Pan, Rubin; Ren, Hugang; Du, Congwu; Kim, Jason; Pan, Yingtian

    2012-03-01

    Because of its high spatial resolution and noninvasive imaging capabilities, optical coherence tomography has been used to characterize the morphological details of various biological tissues including urinary bladder and to diagnose their alternations (e.g., cancers). In addition to static morphology, the dynamic features of tissue morphology can provide important information that can be used to diagnose the physiological and functional characteristics of biological tissues. Here, we present the imaging studies based on optical coherence tomography to characterize motion related physiology and functions of rat bladder detrusor muscles and compared the results with traditional biomechanical measurements. Our results suggest that optical coherence tomography is capable of providing quantitative evaluation of contractile functions of intact bladder (without removing bladder epithelium and connective tissue), which is potentially of more clinical relevance for future clinical diagnosis - if incorporated with cystoscopic optical coherence tomography.

  12. Optical coherence tomography angiography changes in radial peripapillary capillaries in Leber hereditary optic neuropathy

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Matsuzaki

    2018-03-01

    Conclusions and importance: Optical coherence tomography angiography showed LHON from the presymptomatic stage. The results indicate that temporal RPC defects and RFT thinning start to spread once the pseudoedema begins to resolve.

  13. Optimization of coronary optical coherence tomography imaging using the attenuation-compensated technique: a validation study.

    NARCIS (Netherlands)

    Teo, Jing Chun; Foin, Nicolas; Otsuka, Fumiyuki; Bulluck, Heerajnarain; Fam, Jiang Ming; Wong, Philip; Low, Fatt Hoe; Leo, Hwa Liang; Mari, Jean-Martial; Joner, Michael; Girard, Michael J A; Virmani, Renu; Bezerra, HG.; Costa, MA.; Guagliumi, G.; Rollins, AM.; Simon, D.; Gutiérrez-Chico, JL.; Alegría-Barrero, E.; Teijeiro-Mestre, R.; Chan, PH.; Tsujioka, H.; de Silva, R.; Otsuka, F.; Joner, M.; Prati, F.; Virmani, R.; Narula, J.; Members, WC.; Levine, GN.; Bates, ER.; Blankenship, JC.; Bailey, SR.; Bittl, JA.; Prati, F.; Guagliumi, G.; Mintz, G.S.; Costa, Marco; Regar, E.; Akasaka, T.; Roleder, T.; Jąkała, J.; Kałuża, GL.; Partyka, Ł.; Proniewska, K.; Pociask, E.; Girard, MJA.; Strouthidis, NG.; Ethier, CR.; Mari, JM.; Mari, JM.; Strouthidis, NG.; Park, SC.; Girard, MJA.; van der Lee, R.; Foin, N.; Otsuka, F.; Wong, P.K.; Mari, J-M.; Joner, M.; Nakano, M.; Vorpahl, M.; Otsuka, F.; Taniwaki, M.; Yazdani, SK.; Finn, AV.; Nakano, M.; Yahagi, K.; Yamamoto, H.; Taniwaki, M.; Otsuka, F.; Ladich, ER.; Girard, MJ.; Ang, M.; Chung, CW.; Farook, M.; Strouthidis, N.; Mehta, JS.; Foin, N.; Mari, JM.; Nijjer, S.; Sen, S.; Petraco, R.; Ghione, M.; Liu, X.; Kang, JU.; Virmani, R.; Kolodgie, F.D.; Burke, AP.; Farb, A.; Schwartz, S.M.; Yahagi, K.; Kolodgie, F.D.; Otsuka, F.; Finn, AV.; Davis, HR.; Joner, M.; Kume, T.; Akasaka, T.; Kawamoto, T.; Watanabe, N.; Toyota, E.; Neishi, Y.; Rieber, J.; Meissner, O.; Babaryka, G.; Reim, S.; Oswald, M.E.; Koenig, A.S.; Tearney, G. J.; Regar, E.; Akasaka, T.; Adriaenssens, T.; Barlis, P.; Bezerra, HG.; Yabushita, H.; Bouma, BE.; Houser, S. L.; Aretz, HT.; Jang, I-K.; Schlendorf, KH.; Guo, J.; Sun, L.; Chen, Y.D.; Tian, F.; Liu, HB.; Chen, L.; Kawasaki, M.; Bouma, BE.; Bressner, J. E.; Houser, S. L.; Nadkarni, S. K.; MacNeill, BD.; Jansen, CHP.; Onthank, DC.; Cuello, F.; Botnar, RM.; Wiethoff, AJ.; Warley, A.; von Birgelen, C.; Hartmann, A. M.; Kubo, T.; Akasaka, T.; Shite, J.; Suzuki, T.; Uemura, S.; Yu, B.; Habara, M.; Nasu, K.; Terashima, M.; Kaneda, H.; Yokota, D.; Ko, E.; Virmani, R.; Burke, AP.; Kolodgie, F.D.; Farb, A.; Takarada, S.; Imanishi, T.; Kubo, T.; Tanimoto, T.; Kitabata, H.; Nakamura, N.; Hattori, K.; Ozaki, Y.; Ismail, TF.; Okumura, M.; Naruse, H.; Kan, S.; Nishio, R.; Shinke, T.; Otake, H.; Nakagawa, M.; Nagoshi, R.; Inoue, T.; Sinclair, H.D.; Bourantas, C.; Bagnall, A.; Mintz, G.S.; Kunadian, V.; Tearney, G. J.; Yabushita, H.; Houser, S. L.; Aretz, HT.; Jang, I-K.; Schlendorf, KH.; van Soest, G.; Goderie, T.; Regar, E.; Koljenović, S.; Leenders, GL. van; Gonzalo, N.; Xu, C.; Schmitt, JM.; Carlier, SG.; Virmani, R.; van der Meer, FJ; Faber, D.J.; Sassoon, DMB.; Aalders, M.C.; Pasterkamp, G.; Leeuwen, TG. van; Schmitt, JM.; Knuttel, A.; Yadlowsky, M.; Eckhaus, MA.; Karamata, B.; Laubscher, M.; Leutenegger, M.; Bourquin, S.; Lasser, T.; Lambelet, P.; Vermeer, K.A.; Mo, J.; Weda, J.J.A.; Lemij, H.G.; Boer, JF. de

    2016-01-01

    PURPOSE To optimize conventional coronary optical coherence tomography (OCT) images using the attenuation-compensated technique to improve identification of plaques and the external elastic lamina (EEL) contour. METHOD The attenuation-compensated technique was optimized via manipulating contrast

  14. Three-Dimensional Optical Coherence Tomography (3D OCT), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and dramatically...

  15. Morpho-functional evaluation of torpedo maculopathy with optical coherence tomography angiography and microperimetry

    Directory of Open Access Journals (Sweden)

    Gabriela Grimaldi

    2018-06-01

    Full Text Available Purpose: To report the case of a 13-year-old girl with torpedo maculopathy, evaluated with multimodal morpho-functional retinal imaging, including fundus photography, infra-red and blue fundus autofluorescence, swept-source optical coherence tomography (OCT, en face OCT, OCT angiography and microperimetry (MP. Observations: On fundus examination, a torpedo-like hypopigmented lesion was observed temporal to the fovea in the left eye. OCT showed disruption of outer retinal layers and the presence of a subretinal cleft. On OCTA, a diffuse attenuation of signal from choriocapillaris was observed along the lesion. Functional analysis with MP revealed a reduction of retinal sensitivity over the lesion. Conclusions: and importance: On OCTA, torpedo maculopathy is characterized by vascular alterations of the choriocapillaris along the lesion. Keywords: Optical coherence tomography angiography, Torpedo maculopathy, Microperimetry, Swept-source optical coherence tomography, En face optical coherence tomography

  16. Acute Solar Retinopathy Imaged With Adaptive Optics, Optical Coherence Tomography Angiography, and En Face Optical Coherence Tomography.

    Science.gov (United States)

    Wu, Chris Y; Jansen, Michael E; Andrade, Jorge; Chui, Toco Y P; Do, Anna T; Rosen, Richard B; Deobhakta, Avnish

    2018-01-01

    Solar retinopathy is a rare form of retinal injury that occurs after direct sungazing. To enhance understanding of the structural changes that occur in solar retinopathy by obtaining high-resolution in vivo en face images. Case report of a young adult woman who presented to the New York Eye and Ear Infirmary with symptoms of acute solar retinopathy after viewing the solar eclipse on August 21, 2017. Results of comprehensive ophthalmic examination and images obtained by fundus photography, microperimetry, spectral-domain optical coherence tomography (OCT), adaptive optics scanning light ophthalmoscopy, OCT angiography, and en face OCT. The patient was examined after viewing the solar eclipse. Visual acuity was 20/20 OD and 20/25 OS. The patient was left-eye dominant. Spectral-domain OCT images were consistent with mild and severe acute solar retinopathy in the right and left eye, respectively. Microperimetry was normal in the right eye but showed paracentral decreased retinal sensitivity in the left eye with a central absolute scotoma. Adaptive optics images of the right eye showed a small region of nonwaveguiding photoreceptors, while images of the left eye showed a large area of abnormal and nonwaveguiding photoreceptors. Optical coherence tomography angiography images were normal in both eyes. En face OCT images of the right eye showed a small circular hyperreflective area, with central hyporeflectivity in the outer retina of the right eye. The left eye showed a hyperreflective lesion that intensified in area from inner to middle retina and became mostly hyporeflective in the outer retina. The shape of the lesion on adaptive optics and en face OCT images of the left eye corresponded to the shape of the scotoma drawn by the patient on Amsler grid. Acute solar retinopathy can present with foveal cone photoreceptor mosaic disturbances on adaptive optics scanning light ophthalmoscopy imaging. Corresponding reflectivity changes can be seen on en face OCT, especially

  17. Clinical optical coherence tomography combined with multiphoton tomography for evaluation of several skin disorders

    Science.gov (United States)

    König, Karsten; Speicher, Marco; Bückle, Rainer; Reckfort, Julia; McKenzie, Gordon; Welzel, Julia; Koehler, Martin J.; Elsner, Peter; Kaatz, Martin

    2010-02-01

    The first clinical trial of optical coherence tomography (OCT) combined with multiphoton tomography (MPT) and dermoscopy is reported. State-of-the-art (i) OCT systems for dermatology (e.g. multibeam swept source OCT), (ii) the femtosecond laser multiphoton tomograph DermaInspectTM, and (iii) digital dermoscopes were applied to 47 patients with a diversity of skin diseases and disorders such as skin cancer, psoriasis, hemangioma, connective tissue diseases, pigmented lesions, and autoimmune bullous skin diseases. Dermoscopy, also called 'epiluminescent microscopy', provides two-dimensional color images of the skin surface. OCT imaging is based on the detection of optical reflections within the tissue measured interferometrically whereas nonlinear excitation of endogenous fluorophores and the second harmonic generation are the bases of MPT images. OCT cross sectional "wide field" image provides a typical field of view of 5 x 2 mm2 and offers fast information on the depth and the volume of the investigated lesion. In comparison, multiphoton tomography presents 0.36 x 0.36 mm2 horizontal or diagonal sections of the region of interest within seconds with submicron resolution and down to a tissue depth of 200 μm. The combination of OCT and MPT provides a synergistic optical imaging modality for early detection of skin cancer and other skin diseases.

  18. FABRICATION OF TISSUE-SIMULATIVE PHANTOMS AND CAPILLARIES AND THEIR INVESTIGATION BY OPTICAL COHERENCE TOMOGRAPHY TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. V. Bykov

    2013-03-01

    Full Text Available Methods of tissue-simulative phantoms and capillaries fabrication from PVC-plastisol and silicone for application as test-objects in optical coherence tomography (OCT and skin and capillary emulation are considered. Comparison characteristics of these materials and recommendations for their application are given. Examples of phantoms visualization by optical coherence tomography method are given. Possibility of information using from B-scans for refractive index evaluation is shown.

  19. Imaging of basal cell carcinoma by high-definition optical coherence tomography

    DEFF Research Database (Denmark)

    Boone, M A L M; Norrenberg, S; Jemec, G B E

    2012-01-01

    With the continued development of noninvasive therapies for basal cell carcinoma (BCC) such as photodynamic therapy and immune therapies, noninvasive diagnosis and monitoring become increasingly relevant. High-definition optical coherence tomography (HD-OCT) is a high-resolution imaging tool, wit......, with micrometre resolution in both transversal and axial directions, enabling visualization of individual cells up to a depth of around 570 μm, and filling the imaging gap between conventional optical coherence tomography (OCT) and reflectance confocal microscopy (RCM)....

  20. Optical coherence tomography angiography in age-related macular degeneration: The game changer.

    Science.gov (United States)

    Lupidi, Marco; Cerquaglia, Alessio; Chhablani, Jay; Fiore, Tito; Singh, Sumit Randhir; Cardillo Piccolino, Felice; Corbucci, Roberta; Coscas, Florence; Coscas, Gabriel; Cagini, Carlo

    2018-04-01

    Optical coherence tomography angiography is one of the biggest advances in ophthalmic imaging. It enables a depth-resolved assessment of the retinal and choroidal blood flow, far exceeding the levels of detail commonly obtained with dye angiographies. One of the first applications of optical coherence tomography angiography was in detecting the presence of choroidal neovascularization in age-related macular degeneration and establishing its position in relation to the retinal pigmented epithelium and Bruch's membrane, and thereby classifying the CNV as type 1, type 2, type 3, or mixed lesions. Optical coherence tomography angiograms, due to the longer wavelength used by optical coherence tomography, showed a more distinct choroidal neovascularization vascular pattern than fluorescein angiography, since there is less suffering from light scattering or is less obscured by overlying subretinal hemorrhages or exudation. Qualitative and quantitative assessments of optical coherence tomography angiography findings in exudative and nonexudative age-related macular degeneration have been largely investigated within the past 3 years both in clinical and experimental settings. This review constitutes an up-to-date of all the potential applications of optical coherence tomography angiography in age-related macular degeneration in order to better understand how to translate its theoretical usefulness into the current clinical practice.

  1. Ethnic differences in trabecular meshwork height by optical coherence tomography.

    Science.gov (United States)

    Chen, Rebecca I; Barbosa, Diego T; Hsu, Chi-Hsin; Porco, Travis C; Lin, Shan C

    2015-04-01

    Differences in ocular anatomy may contribute to ethnic differences in glaucoma risk. Because the trabecular meshwork (TM) plays an important role in aqueous outflow, its anatomy in relation to at-risk populations may provide insight into a potential contributor to elevated intraocular pressure and thus to probability of glaucoma development. To investigate whether differences exist in TM height between ethnic groups. This prospective study took place from January 1, 2012, to December 31, 2013. Adult patients who self-reported as being of white, Asian, Hispanic, or African American ethnicity were recruited from ophthalmology clinics at the University of California, San Francisco. The TM height was assessed using spectral-domain anterior segment optical coherence tomography. Trabecular meshwork height was measured from the scleral spur to the Schwalbe line. We hypothesized that ethnicities with a higher prevalence of glaucoma would tend to have shorter TM heights. We collected data from 460 eyes of 291 participants after excluding 34 optical coherence tomographic scans owing to poor image quality. The final sample was 32.2% white, 45.1% Asian, 10.5% African American, and 12.1% Hispanic. There were 64.2% women, and the mean age was 68.1 years. The mean (SD) TM height among all eyes included in the study was 836 (131) μm. The mean (SD) TM height was characterized among white (851 [131] μm), Asian (843 [126] μm), Hispanic (822 [147] μm), and African American (771 [118] μm) persons. Ethnicity was not associated with TM height overall (P = .23, linear mixed regression model). However, the TM heights of African American participants (771 μm) were shorter than those of white (851 μm; adjusted difference 95% CI, -119.8 to -8.1; P = .02) and Asian (843 μm; adjusted difference 95% CI, -117.4 to -10.8; P = .02) participants. Although TM height is not associated with ethnicity overall, African American individuals have shorter TM heights compared with Asian and white

  2. Can duplex Doppler ultrasound replace computerized tomography in staging patients with renal cell carcinoma?

    NARCIS (Netherlands)

    Bos, SD; Mensink, HJA

    The purpose of this study was to evaluate the accuracy and reliability of duplex Doppler ultrasound (US) and computerized tomography (CT) in staging patients with renal cell carcinoma (RCC). Sixty-six patients were evaluated pre-operatively with duplex Doppler ultrasound and CT. The results were

  3. Computed Tomography and Ultrasound Diagnosis of Spontaneous Subcapsular Renal Hematoma

    Directory of Open Access Journals (Sweden)

    Samer Assaf

    2018-01-01

    Full Text Available History of present illness: A 58-year-old female with history of thrombotic disorder presented to emergency department (ED with constant, sharp pain in her lower abdomen radiating to her back for the past day. She denied nausea, vomiting, changes in bowel habits, or recent abdominal trauma. The patient had been recently transitioned from warfarin to enoxaparin after having a shoulder surgery one week prior to her presentation. On exam, the patient was tachycardic, hypotensive, and pale. She had significant abdominal tenderness to the left upper and lower quadrants, and left flank. Her initial hemoglobin (Hbg was 8.9 g/dL, but dropped to 6.1 g/dL during her ED course, requiring emergent blood transfusion. Significant findings: Bedside ultrasound was performed and demonstrated a hypoechoic area within the left kidney (images not shown. The non-contrast computed tomography (CT of the abdomen and pelvis shows a significantly enlarged left kidney and a region of high-attenuation encapsulating the left kidney, concerning for acute hemorrhage. Discussion: The cause for spontaneous subcapsular renal hematoma (SPH is not entirely clear.1 It may mimic acute appendicitis or a dissecting aneurysm.2 The use of ultrasound in the emergency setting can detect SPH; however, CT is preferred because it can distinguish between a renal mass, abscess, or collection of blood.3 Most SPH cases are associated with renal tumors, and radical nephrectomy is recommended.4 When the etiology cannot be determined, conservative management may be appropriate.5 The use of anticoagulant and antiplatelet medications may be a predisposing factor, since their usage has been implicated in cases of SPH in the past.4,6 This patient was evaluated by interventional radiology, but she was not a candidate for embolization due to a significant contrast allergy. She was therefore admitted to general surgery and underwent exploratory laparotomy. A left-sided adrenal mass was discovered with

  4. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Carina Mari Aparici

    2016-01-01

    Full Text Available We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  5. The use of optical coherence tomography in maxillofacial surgery

    Science.gov (United States)

    Al-Obaidi, Mohammed; Tandon, Rahul; Tiwana, Paul

    2015-02-01

    The ever-evolving medical field continues to trend toward less invasive approaches to the diagnosis and treatment of pathological conditions. Basic sciences research has allowed for improved technologies that are translated to the clinical sciences. Similarly, advancements in imaging modalities continue to improve and their applications become more varied. As such, surgeons and pathologists are able to depend on smaller samples for tissue diagnosis of pathological disease, where once large sections of tissue were needed. Optical coherence tomography (OCT), a high-resolution imaging technique, has been used extensively in different medical fields to improve diagnostic yield. Its use in dental fields, particularly in oral and maxillofacial surgery, remains limited. Our goal is to assess the use of OCT for improving soft tissue analysis and diagnosis, particularly for its applications in the field of oral and maxillofacial surgery. Optical coherence tomography is a modality that uses an optical signal using safe near-infrared light which is reflected off the sub-surface structures. This allows for high-resolution cross-sectional images of the tissue morphology to be obtained. Ophthalmologists have been using OCT to obtain images of the retina to assess for age-related macular degeneration. More recently, OCT has been used by Interventional Cardiology to image coronary arteries, and assess plaque thickness and morphology. This technology is now being investigated in several medical fields as a form of optical biopsy, providing in situ images with high-resolution morphology of tissues. We are particularly interested in its use on epithelial tissues, and therefore performed a literature review on the use of OCT for assessing epithelium. Evaluation of histologically-diagnosed actinic keratosis, for example, was found to correlate well with the imaging discrepancies found on OCT; and the in vivo assessment of atypical keratinocytes was firmly established. Additionally

  6. SOUND-SPEED TOMOGRAPHY USING FIRST-ARRIVAL TRANSMISSION ULTRASOUND FOR A RING ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    HUANG, LIANJIE [Los Alamos National Laboratory; QUAN, YOULI [Los Alamos National Laboratory

    2007-01-31

    Sound-speed tomography images can be used for cancer detection and diagnosis. Tumors have generally higher sound speeds than the surrounding tissue. Quality and resolution of tomography images are primarily determined by the insonification/illumination aperture of ultrasound and the capability of the tomography method for accurately handling heterogeneous nature of the breast. We investigate the capability of an efficient time-of-flight tomography method using transmission ultrasound from a ring array for reconstructing sound-speed images of the breast. The method uses first arrival times of transmitted ultrasonic signals emerging from non-beamforming ultrasound transducers located around a ring. It properly accounts for ray bending within the breast by solving the eikonal equation using a finite-difference scheme. We test and validate the time-of-flight transmission tomography method using synthetic data for numerical breast phantoms containing various objects. In our simulation, the objects are immersed in water within a ring array. Two-dimensional synthetic data are generated using a finite-difference scheme to solve acoustic-wave equation in heterogeneous media. We study the reconstruction accuracy of the tomography method for objects with different sizes and shapes as well as different perturbations from the surrounding medium. In addition, we also address some specific data processing issues related to the tomography. Our tomography results demonstrate that the first-arrival transmission tomography method can accurately reconstruct objects larger than approximately five wavelengths of the incident ultrasound using a ring array.

  7. Validation of optical coherence tomography in vivo using cryostat histology

    International Nuclear Information System (INIS)

    Gambichler, T; Moussa, G; Regeniter, P; Kasseck, C; Hofmann, M R; Bechara, F G; Sand, M; Altmeyer, P; Hoffmann, K

    2007-01-01

    We aimed to validate for the first time optical coherence tomography (OCT) measurements of epidermal thickness (ET) using cryopreparation for histology. OCT assessments of ET were performed on healthy skin using the algorithms as follows: first, peak-to-valley analysis of the A-scan (ET-OCT-V), second, line-traced image analysis of the B-scan (ET-OCT-IA). Histology was performed using cryostat sections which were also evaluated using the image analysis (ET-Histo). We selected 114 samples, including B-scans and corresponding histology, for method comparison between ET-OCT-IA and ET-Histo. Forty-two A-scans were available for method comparison between ET-OCT-V and ET-Histo. Bland and Altman plots revealed a marked bias with wide 95% limits of agreement for ET-OCT-V versus ET-Histo. Comparison of ET-OCT-IA versus ET-Histo revealed only a slight bias and narrow 95% limits of agreement. A-scan analysis for ET determination is linked to significant limitations and lacks agreement with histology. By contrast, we observed satisfactory agreement between ET-OCT-IA and ET-Histo indicating that both methods can be utilized interchangeably. OCT using the line-traced image analysis of the B-scan appears to be a valid and relatively practicable method for the determination of ET in vivo. Furthermore, the comparisons with the in vivo OCT profiles demonstrate that cryostat sectioning provides a better preservation of relative and absolute dimensions of skin layers than paraffin embedding. (note)

  8. Optical coherence tomography in the diagnosis of scleritis and episcleritis.

    Science.gov (United States)

    Shoughy, Samir S; Jaroudi, Mahmoud O; Kozak, Igor; Tabbara, Khalid F

    2015-06-01

    To describe the optical coherence tomography (OCT) findings in eyes with active anterior scleritis and compare the findings to those with episcleritis and normal controls. Prospective evaluation of a diagnostic test. We included a total of 30 eyes of 30 patients with unilateral anterior scleral or episcleral inflammation. The contralateral 30 eyes with no active ocular disease served as controls. OCT was performed over the anterior sclera in the inflamed area on all cases. The OCT images were analyzed to determine the thickness of the sclera and the presence or absence of scleral hyporeflective areas representing intrascleral edema. There were 17 male and 13 female patients. The mean age was 43 years with an age range of 21-77 years. Eighteen patients had anterior scleritis and 12 patients had episcleritis. The mean transconjunctival scleral thickness was 747 μm (SD ± 68.97) with a range of 616-877 μm in normal eyes, 882 μm (SD ± 87.35) with a range of 773-1089 μm in patients with scleritis, and 825 μm (SD ± 85.57) with a range of 718-949 μm in patients with episcleritis. Patients with active anterior scleritis showed increased thickness of the sclera and presence of intrascleral hyporeflective areas of edema by OCT compared to patients with episcleritis and normal eyes. OCT adds both qualitative and quantitative information to diagnosis and monitoring of patients with scleritis. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Measurement of ciliary beat frequency using Doppler optical coherence tomography.

    Science.gov (United States)

    Lemieux, Bryan T; Chen, Jason J; Jing, Joseph; Chen, Zhongping; Wong, Brian J F

    2015-11-01

    Measuring ciliary beat frequency (CBF) is a technical challenge and difficult to perform in vivo. Doppler optical coherence tomography (D-OCT) is a mesoscopic noncontact imaging modality that provides high-resolution tomographic images and detects micromotion simultaneously in living tissues. In this work we used D-OCT to measure CBF in ex vivo tissue as the first step toward translating this technology to clinical use. Fresh ex vivo samples of rabbit tracheal mucosa were imaged using both D-OCT and phase-contrast microscopy (n = 5). The D-OCT system was designed and built to specification in our lab (1310-nm swept source vertical-cavity surface-emitting laser [VCSEL], 6-μm axial resolution). The samples were placed in culture and incubated at 37°C. A fast Fourier transform was performed on the D-OCT signal recorded on the surface of the samples to gauge CBF. High-speed digital video of the epithelium recorded via phase-contrast microscopy was analyzed to confirm the CBF measurements. The D-OCT system detected Doppler signal at the epithelial layer of ex vivo rabbit tracheal samples suggestive of ciliary motion. CBF was measured at 9.36 ± 1.22 Hz using D-OCT and 9.08 ± 0.48 Hz using phase-contrast microscopy. No significant differences were found between the 2 methods (p > 0.05). D-OCT allows for the quantitative measurement of CBF without the need to resolve individual cilia. Furthermore, D-OCT technology can be incorporated into endoscopic platforms that allow clinicians to readily measure CBF in the office and provide a direct measurement of mucosal health. © 2015 ARS-AAOA, LLC.

  10. Optical coherence tomography using the Niris system in otolaryngology

    Science.gov (United States)

    Rubinstein, Marc; Armstrong, William B.; Djalilian, Hamid R.; Crumley, Roger L.; Kim, Jason H.; Nguyen, Quoc A.; Foulad, Allen I.; Ghasri, Pedram E.; Wong, Brian J. F.

    2009-02-01

    Objectives: To determine the feasibility and accuracy of the Niris Optical Coherence Tomography (OCT) system in imaging of the mucosal abnormalities of the head and neck. The Niris system is the first commercially available OCT device for applications outside ophthalmology. Methods: We obtained OCT images of benign, premalignant and malignant lesions throughout the head and neck, using the Niris OCT imaging system (Imalux, Cleveland, OH). This imaging system has a tissue penetration depth of approximately 1-2mm, a scanning range of 2mm and a spatial depth resolution of approximately 10-20μm. Imaging was performed in the outpatient setting and in the operating room using a flexible probe. Results: High-resolution cross-sectional images from the oral cavity, nasal cavity, ears and larynx showed distinct layers and structures such as mucosa layer, basal membrane and lamina propria, were clearly identified. In the pathology images disruption of the basal membrane was clearly shown. Device set-up took approximately 5 minutes and the image acquisition was rapid. The system can be operated by the person performing the exam. Conclusions: The Niris system is non invasive and easy to incorporate into the operating room and the clinic. It requires minimal set-up and requires only one person to operate. The unique ability of the OCT offers high-resolution images showing the microanatomy of different sites. OCT imaging with the Niris device potentially offers an efficient, quick and reliable imaging modality in guiding surgical biopsies, intra-operative decision making, and therapeutic options for different otolaryngologic pathologies and premalignant disease.

  11. Spectral-domain optical coherence tomography of macula in myopia.

    Science.gov (United States)

    Choovuthayakorn, Janejit; Laowong, Taksaorn; Watanachai, Nawat; Patikulsila, Direk; Chaikitmongkol, Voraporn

    2016-06-01

    The aim of this study is to determine the associations between regional macular thickness and gender, age, axial length, and degree of myopia in young and middle-aged healthy myopic eyes. One hundred and seventy-one subjects with -0.5 diopters of myopia or worse underwent prospective macular thickness measurement by Spectralis spectral-domain optical coherence tomography. Subjects' mean age was 32.40 ± 8.25 years (range 18 to 49 years), with 45 % being male. The mean degree of myopia was -4.57 ± 3.52 diopters, with a mean axial length of 25.09 ± 1.67 mm. Multivariate regression analysis demonstrated significantly thicker central (mean 9.13 µm thicker) and inner subfields (mean 8.55 µm thicker) in males (P values were <0.001 and 0.002, respectively). In addition, in both genders, for each millimeter of increased axial length, the central subfield thickness increased by 2.11 µm, the inner subfield decreased by 2.25 µm, and the outer subfield decreased by 3.62 µm (P values were 0.010, <0.001, and <0.001, respectively). Factors including gender and axial length affect baseline regional macular thickness in young and middle-age myopic subjects. The central subfield and inner subfield were affected by both gender and axial length, while the outer subfield was affected only by axial length. The macular thickness of myopic subjects with macular disease should be interpreted in light of these factors.

  12. Learnable despeckling framework for optical coherence tomography images

    Science.gov (United States)

    Adabi, Saba; Rashedi, Elaheh; Clayton, Anne; Mohebbi-Kalkhoran, Hamed; Chen, Xue-wen; Conforto, Silvia; Nasiriavanaki, Mohammadreza

    2018-01-01

    Optical coherence tomography (OCT) is a prevalent, interferometric, high-resolution imaging method with broad biomedical applications. Nonetheless, OCT images suffer from an artifact called speckle, which degrades the image quality. Digital filters offer an opportunity for image improvement in clinical OCT devices, where hardware modification to enhance images is expensive. To reduce speckle, a wide variety of digital filters have been proposed; selecting the most appropriate filter for an OCT image/image set is a challenging decision, especially in dermatology applications of OCT where a different variety of tissues are imaged. To tackle this challenge, we propose an expandable learnable despeckling framework, we call LDF. LDF decides which speckle reduction algorithm is most effective on a given image by learning a figure of merit (FOM) as a single quantitative image assessment measure. LDF is learnable, which means when implemented on an OCT machine, each given image/image set is retrained and its performance is improved. Also, LDF is expandable, meaning that any despeckling algorithm can easily be added to it. The architecture of LDF includes two main parts: (i) an autoencoder neural network and (ii) filter classifier. The autoencoder learns the FOM based on several quality assessment measures obtained from the OCT image including signal-to-noise ratio, contrast-to-noise ratio, equivalent number of looks, edge preservation index, and mean structural similarity index. Subsequently, the filter classifier identifies the most efficient filter from the following categories: (a) sliding window filters including median, mean, and symmetric nearest neighborhood, (b) adaptive statistical-based filters including Wiener, homomorphic Lee, and Kuwahara, and (c) edge preserved patch or pixel correlation-based filters including nonlocal mean, total variation, and block matching three-dimensional filtering.

  13. Electrophysiology and optical coherence tomography to evaluate Parkinson disease severity.

    Science.gov (United States)

    Garcia-Martin, Elena; Rodriguez-Mena, Diego; Satue, Maria; Almarcegui, Carmen; Dolz, Isabel; Alarcia, Raquel; Seral, Maria; Polo, Vicente; Larrosa, Jose M; Pablo, Luis E

    2014-02-04

    To evaluate correlations between visual evoked potentials (VEP), pattern electroretinogram (PERG), and macular and retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and the severity of Parkinson disease (PD). Forty-six PD patients and 33 age and sex-matched healthy controls were enrolled, and underwent VEP, PERG, and OCT measurements of macular and RNFL thicknesses, and evaluation of PD severity using the Hoehn and Yahr scale to measure PD symptom progression, the Schwab and England Activities of Daily Living Scale (SE-ADL) to evaluate patient quality of life (QOL), and disease duration. Logistical regression was performed to analyze which measures, if any, could predict PD symptom progression or effect on QOL. Visual functional parameters (best corrected visual acuity, mean deviation of visual field, PERG positive (P) component at 50 ms -P50- and negative (N) component at 95 ms -N95- component amplitude, and PERG P50 component latency) and structural parameters (OCT measurements of RNFL and retinal thickness) were decreased in PD patients compared with healthy controls. OCT measurements were significantly negatively correlated with the Hoehn and Yahr scale, and significantly positively correlated with the SE-ADL scale. Based on logistical regression analysis, fovea thickness provided by OCT equipment predicted PD severity, and QOL and amplitude of the PERG N95 component predicted a lower SE-ADL score. Patients with greater damage in the RNFL tend to have lower QOL and more severe PD symptoms. Foveal thicknesses and the PERG N95 component provide good biomarkers for predicting QOL and disease severity.

  14. Neurosurgical hand-held optical coherence tomography (OCT) forward-viewing probe

    Science.gov (United States)

    Sun, Cuiru; Lee, Kenneth K. C.; Vuong, Barry; Cusimano, Michael; Brukson, Alexander; Mariampillai, Adrian; Standish, Beau A.; Yang, Victor X. D.

    2012-02-01

    A prototype neurosurgical hand-held optical coherence tomography (OCT) imaging probe has been developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic hand-held probe has been designed based on our group's previous work on electrostatically driven optical fibers. It has been packaged into a catheter probe in the familiar form factor of the clinically accepted Bayonet shaped neurosurgical non-imaging Doppler ultrasound probes. The optical design was optimized using ZEMAX simulation. Optical properties of the probe were tested to yield an ~20 um spot size, 5 mm working distance and a 3.5 mm field of view. The scan frequency can be increased or decreased by changing the applied voltage. Typically a scan frequency of less than 60Hz is chosen to keep the applied voltage to less than 2000V. The axial resolution of the probe was ~15 um (in air) as determined by the OCT system. A custom-triggering methodology has been developed to provide continuous stable imaging, which is crucial for clinical utility. Feasibility of this probe, in combination with a 1310 nm swept source OCT system was tested and images are presented to highlight the usefulness of such a forward viewing handheld OCT imaging probe. Knowledge gained from this research will lay the foundation for developing new OCT technologies for endovascular management of cerebral aneurysms and transsphenoidal neuroendoscopic treatment of pituitary tumors.

  15. Resonant acoustic spectroscopy of soft tissues using embedded magnetomotive nanotransducers and optical coherence tomography

    International Nuclear Information System (INIS)

    Oldenburg, Amy L; Boppart, Stephen A

    2010-01-01

    We present a new method for performing dynamic elastography of soft tissue samples. By sensing nanoscale displacements with optical coherence tomography, a chirped, modulated force is applied to acquire the mechanical spectrum of a tissue sample within a few seconds. This modulated force is applied via magnetic nanoparticles, named 'nanotransducers', which are diffused into the tissue, and which contribute negligible inertia to the soft tissue mechanical system. Using this novel system, we observed that excised tissues exhibit mechanical resonance modes which are well described by a linear damped harmonic oscillator. Results are validated by using cylindrical tissue phantoms of agarose in which resonant frequencies (30-400 Hz) are consistent with longitudinal modes and the sample boundary conditions. We furthermore show that the Young's modulus can be computed from their measured resonance frequencies, analogous to resonant ultrasound spectroscopy for stiff material analysis. Using this new technique, named magnetomotive resonant acoustic spectroscopy (MRAS), we monitored the relative stiffening of an excised rat liver during a chemical fixation process.

  16. Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy.

    Science.gov (United States)

    Tardif, Pier-Luc; Bertrand, Marie-Jeanne; Abran, Maxime; Castonguay, Alexandre; Lefebvre, Joël; Stähli, Barbara E; Merlet, Nolwenn; Mihalache-Avram, Teodora; Geoffroy, Pascale; Mecteau, Mélanie; Busseuil, David; Ni, Feng; Abulrob, Abedelnasser; Rhéaume, Éric; L'Allier, Philippe; Tardif, Jean-Claude; Lesage, Frédéric

    2016-12-15

    Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology.

  17. Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

    DEFF Research Database (Denmark)

    Falk, Erling

    2012-01-01

    The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving...

  18. Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies : A report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

    NARCIS (Netherlands)

    G.J. Tearney (Guillermo); E.S. Regar (Eveline); T. Akasaka (Takashi); S. Adriaenssens (Stef); P. Barlis (Peter); H.G. Bezerra (Hiram); B.E. Bouma (Brett); N. Bruining (Nico); J.-M. Cho (Jin-Man); S. Chowdhary (Saqib); M.A. Costa (Marco); R. de Silva (Ranil); J. Dijkstra (Jouke); C. di Mario (Carlo); D. Dudeck (Darius); E. Falk (Erling); M.D. Feldman (Marc); P.J. Fitzgerald (Peter); H.M. Garcia-Garcia (Hector); N. Gonzalo (Nieves); J.F. Granada (Juan); G. Guagliumi (Giulio); N.R. Holm (Niels); Y. Honda (Yasuhiro); F. Ikeno (Fumiaki); Y. Kawasaki; W. Kochman (Waclav); L. Koltowski (Lukasz); T. Kubo (Takashi); T. Kume (Teruyoshi); H. Kyono (Hiroyuki); C.C.S. Lam (Cheung Chi Simon); G. Lamouche (Guy); D.P. Lee (David); M.B. Leon (Martin); A. Maehara (Akiko); O. Manfrini (Olivia); G.S. Mintz (Gary); K. Mizuno (Kyiouchi); M-A.M. Morel (Marie-Angèle); S. Nadkarni (Seemantini); H. Okura (Hiroyuki); H. Otake (Hiromasa); A. Pietrasik (Arkadiusz); F. Prati (Francesco); L. Rber (Lorenz); M. Radu (Maria); N. Rieber (Nikolaus); M. Riga (Maria); S.M. Rollins; M. Rosenberg (Mireille); V. Sirbu (Vasile); P.W.J.C. Serruys (Patrick); K. Shimada; T. Shinke (Toshiro); J. Shite (Junya); E. Siegel (Eliot); S. Sonada (Shinjo); U. Suter (Ueli); S. Takarada (Shigeho); A. Tanaka (Atsushi); M. Terashima (Mitsuyasu); T. Troels (Thim); M. Uemura (Mayu); G.J. Ughi (Giovanni); H.M.M. van Beusekom (Heleen); A.F.W. van der Steen (Ton); G.A. van Es (Gerrit Anne); G. van Soest (Gijs); R. Virmani (Renu); S. Waxman (Sergio); N.J. Weissman (Neil); G. Weisz (Giora)

    2012-01-01

    textabstractObjectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the

  19. Diffuse optical tomography using semiautomated coregistered ultrasound measurements

    Science.gov (United States)

    Mostafa, Atahar; Vavadi, Hamed; Uddin, K. M. Shihab; Zhu, Quing

    2017-12-01

    Diffuse optical tomography (DOT) has demonstrated huge potential in breast cancer diagnosis and treatment monitoring. DOT image reconstruction guided by ultrasound (US) improves the diffused light localization and lesion reconstruction accuracy. However, DOT reconstruction depends on tumor geometry provided by coregistered US. Experienced operators can manually measure these lesion parameters; however, training and measurement time are needed. The wide clinical use of this technique depends on its robustness and faster imaging reconstruction capability. This article introduces a semiautomated procedure that automatically extracts lesion information from US images and incorporates it into the optical reconstruction. An adaptive threshold-based image segmentation is used to obtain tumor boundaries. For some US images, posterior shadow can extend to the chest wall and make the detection of deeper lesion boundary difficult. This problem can be solved using a Hough transform. The proposed procedure was validated from data of 20 patients. Optical reconstruction results using the proposed procedure were compared with those reconstructed using extracted tumor information from an experienced user. Mean optical absorption obtained from manual measurement was 0.21±0.06 cm-1 for malignant and 0.12±0.06 cm-1 for benign cases, whereas for the proposed method it was 0.24±0.08 cm-1 and 0.12±0.05 cm-1, respectively.

  20. Automated breast segmentation in ultrasound computer tomography SAFT images

    Science.gov (United States)

    Hopp, T.; You, W.; Zapf, M.; Tan, W. Y.; Gemmeke, H.; Ruiter, N. V.

    2017-03-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging system for breast cancer diagnosis. An essential step before further processing is to remove the water background from the reconstructed images. In this paper we present a fully-automated image segmentation method based on three-dimensional active contours. The active contour method is extended by applying gradient vector flow and encoding the USCT aperture characteristics as additional weighting terms. A surface detection algorithm based on a ray model is developed to initialize the active contour, which is iteratively deformed to capture the breast outline in USCT reflection images. The evaluation with synthetic data showed that the method is able to cope with noisy images, and is not influenced by the position of the breast and the presence of scattering objects within the breast. The proposed method was applied to 14 in-vivo images resulting in an average surface deviation from a manual segmentation of 2.7 mm. We conclude that automated segmentation of USCT reflection images is feasible and produces results comparable to a manual segmentation. By applying the proposed method, reproducible segmentation results can be obtained without manual interaction by an expert.

  1. Determination of characteristics of degenerative joint disease using optical coherence tomography and polarization sensitive optical coherence tomography.

    Science.gov (United States)

    Xie, Tuqiang; Guo, Shuguang; Zhang, Jun; Chen, Zhongping; Peavy, George M

    2006-10-01

    Previous studies have demonstrated that optical coherence tomography (OCT) could be used to delineate alterations in the microstructure of cartilage, and have suggested that changes in the polarization state of light as detected by OCT could provide information on the birefringence properties of articular cartilage as influenced by disease. In this study we have used both OCT and polarization sensitive optical coherence tomography (PS-OCT) technologies to evaluate normal and abnormal bovine articular cartilage according to established structural, organizational, and birefringent characteristics of degenerative joint disease (DJD) in order to determine if this technology can be used to differentiate various stages of DJD as a minimally invasive imaging tool. Fresh bovine femoral-tibial joints were obtained from an abattoir, and 45 cartilage specimens were harvested from 8 tibial plateaus. Whole ex vivo specimens of normal and degenerative articular cartilage were imaged by both OCT and PS-OCT, then fixed and processed for histological evaluation. OCT/PS-OCT images and corresponding histology sections of each specimen were scored according to a modified Mankin structural grading scale and compared. OCT and PS-OCT imaging allowed structural evaluation of intact articular cartilage along a 6 mm surface length to a depth of 2 mm with a transverse resolution of 12 microm and an axial resolution of 10 microm. The OCT and PS-OCT images demonstrated characteristic alterations in the structure of articular cartilage with a high correlation to histological evaluation (kappa = 0.776). The OCT images were able to demonstrate early to advanced structural changes of articular cartilage while the optical phase retardation images obtained by PS-OCT imaging were able to discriminate areas where disorganization of the cartilage matrix was present, however, these characteristics are much different than those reported where OCT images alone were used to characterize tissue

  2. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography.

    Science.gov (United States)

    Tay, Elton Lik Tong; Yong, Vernon Khet Yau; Lim, Boon Ang; Sia, Stelson; Wong, Elizabeth Poh Ying; Yip, Leonard Wei Leon

    2015-01-01

    To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography (AS-OCT), as well as gonioscopy and spectral domain OCT (SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments. Seventeen consecutive subjects (33 eyes) were recruited from the study hospital's Glaucoma clinic. Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other's analyses of OCT images. Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively (Pgonioscopy was fair at k=0.31 (95% confidence interval, CI: 0.03-0.59) and k=0.35 (95% CI: 0.07-0.63) for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k=0.21 (95% CI: 0.07-0.49) and slight at k=0.17 (95% CI: 0.08-0.42) for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51 (95% CI: 0.13-0.88). The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18 (95% CI: 0.08-0.45). Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively.

  3. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Elton Lik Tong Tay

    2015-04-01

    Full Text Available AIM: To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography (AS-OCT, as well as gonioscopy and spectral domain OCT (SD-OCT. A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments. METHODS: Seventeen consecutive subjects (33 eyes were recruited from the study hospital’s Glaucoma clinic. Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other’s analyses of OCT images. RESULTS: Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively (P<0.01. The agreement for angle closure between AS-OCT and gonioscopy was fair at k=0.31 (95% confidence interval, CI: 0.03-0.59 and k=0.35 (95% CI: 0.07-0.63 for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k=0.21 (95% CI: 0.07-0.49 and slight at k=0.17 (95% CI: 0.08-0.42 for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51 (95% CI: 0.13-0.88. The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18 (95% CI: 0.08-0.45. CONCLUSION: Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively.

  4. 3D Human cartilage surface characterization by optical coherence tomography

    International Nuclear Information System (INIS)

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Jahr, Holger; Nebelung, Sven; Truhn, Daniel; Pufe, Thomas

    2015-01-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

  5. Keratometric index obtained by Fourier-domain optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Yanjun Hua

    Full Text Available To determine the keratometric indices calculated based on parameters obtained by Fourier-domain optical coherence tomography (FD-OCT.The ratio of anterior corneal curvature to posterior corneal curvature (Ratio and keratometric index (N were calculated within central 3 mm zone with the RTVue FD-OCT (RTVue, Optovue, Inc. in 186 untreated eyes, 60 post-LASIK/PRK eyes, and 39 keratoconus eyes. The total corneal powers were calculated using different keratometric indices: Kcal based on the mean calculated keratometric index, K1.3315 calculated by the keratometric index of 1.3315, and K1.3375 calculated by the keratometric index of 1.3375. In addition, the total corneal powers based on Gaussian optics formula (Kactual were calculated.The means for Ratio in untreated controls, post-LASIK/PRK group and keratoconus group were 1.176 ± 0.022 (95% confidence interval (CI, 1.172-1.179, 1.314 ± 0.042 (95%CI, 1.303-1.325 and 1.229 ± 0.118 (95%CI, 1.191-1.267, respectively. And the mean calculated keratometric index in untreated controls, post-LASIK/PRK group and keratoconus group were 1.3299 ± 0.00085 (95%CI, 1.3272-1.3308, 1.3242 ± 0.00171 (95%CI, 1.3238-1.3246 and 1.3277 ± 0.0046 (95%CI, 1.3263-1.3292, respectively. All the parameters were normally distributed. The differences between Kcal and Kactual, K1.3315 and Kactual, and K1.3375 and Kactual were 0.00 ± 0.11 D, 0.21 ± 0.11 D and 0.99 ± 0.12 D, respectively, in untreated controls; -0.01 ± 0.20 D, 0.85 ± 0.18 D and 1.56 ± 0.16 D, respectively, in post-LASIK/PRK group; and 0.03 ± 0.67 D, 0.56 ± 0.70 D and 1.40 ± 0.76 D, respectively, in keratoconus group.The calculated keratometric index is negatively related to the ratio of anterior corneal curvature to posterior corneal curvature in untreated, post-LASIK/PRK, and keratoconus eyes, respectively. Using the calculated keratometric index may improve the prediction accuracies of total corneal powers in untreated controls, but not in post

  6. Optical Coherence Tomography in Alzheimer's Disease: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Gianluca Coppola

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disorder, which is likely to start as mild cognitive impairment (MCI several years before the its full-blown clinical manifestation. Optical coherence tomography (OCT has been used to detect a loss in peripapillary retina nerve fiber layer (RNFL and a reduction in macular thickness and volume of people affected by MCI or AD. Here, we performed an aggregate meta-analysis combining results from different studies.Data sources were case-control studies published between January 2001 and August 2014 (identified through PubMed and Google Scholar databases that examined the RNFL thickness by means of OCT in AD and MCI patients compared with cognitively healthy controls.11 studies were identified, including 380 patients with AD, 68 with MCI and 293 healthy controls (HC. The studies suggest that the mean RNFL thickness is reduced in MCI (weighted mean differences in μm, WMD = -13.39, 95% CI: -17.34 to -9.45, p = 0.031 and, even more so, in AD (WMD = -15.95, 95% CI: -21.65 to -10.21, p<0.0001 patients compared to HC. RNFL in the 4 quadrants were all significantly thinner in AD superior (superior WMD = -24.0, 95% CI: -34.9 to -13.1, p<0.0001; inferior WMD = -20.8, 95% CI: -32.0 to -9.7, p<0.0001; nasal WMD = -14.7, 95% CI: -23.9 to -5.5, p<0.0001; and temporal WMD = -10.7, 95% CI: -19.9 to -1.4, p<0.0001; the same significant reduction in quadrant RNFL was observed in MCI patients compared with HC (Inferior WMD = -20.22, 95% CI: -30.41 to -10.03, p = 0.0001; nasal WMD = -7.4, 95% CI: -10.08 to -4.7, p = 0.0000; and temporal WMD = -6.88, 95% CI: -12.62 to -1.13, p = 0.01, with the exception of superior quadrant (WMD = -19.45, 95% CI: -40.23 to 1.32, p = 0.06.Results from the meta-analysis support the important role of OCT for RNFL analysis in monitoring the progression of AD and in assessing the effectiveness of purported AD treatments.

  7. Optical Coherence Tomography Angiography Characteristics of Iris Melanocytic Tumors

    Science.gov (United States)

    Skalet, Alison H.; Li, Yan; Lu, Chen D.; Jia, Yali; Lee, ByungKun; Husvogt, Lennart; Maier, Andreas; Fujimoto, James G.; Thomas, Charles R.; Huang, David

    2016-01-01

    Objective To evaluate tumor vasculature with optical coherence tomography (OCT) angiography (OCTA) in malignant iris melanomas and benign iris lesions. Design Cross-sectional observational clinical study. Participants Patients with iris lesions and healthy volunteers. Methods Eyes were imaged using OCTA systems operating at 1050 and 840 nm wavelengths. Three-dimensional OCTA scans were acquired. Iris melanomas patients treated with radiation therapy were imaged again after I-125 plaque brachytherapy at 6 and 18 months. Main Outcome Measures OCT and OCTA images, qualitative evaluation of iris and tumor vasculature and quantitative vessel density. Results One eye each of eight normal volunteers and nine patients with iris melanomas or benign iris lesions including freckles, nevi, and an iris pigment epithelial (IPE) cyst were imaged. The normal iris has radially-oriented vessels within the stroma on OCTA. Penetration of flow signal in normal iris depended on iris color, with best penetration seen in light to moderately pigmented irides. Iris melanomas demonstrated tortuous and disorganized intratumoral vasculature. In two eyes with nevi there was no increased vascularity; in another, fine vascular loops were noted near an area of ectropion uveae. Iris freckles and the IPE cyst did not have intrinsic vascularity. The vessel density was significantly higher within iris melanomas (34.5%±9.8%, piris nevi (8.0%±1.4%) or normal irides (8.0%±1.2%). Tumor regression after radiation therapy for melanomas was associated with decreased vessel density. OCTA at 1050 nm provided better visualization of tumor vasculature and penetration through thicker tumors than at 840 nm. But in very thick tumors and highly pigmented lesions even 1050 nm OCTA could not visualize their full thickness. Interpretable OCTA images were obtained in 82% participants in whom imaging was attempted. Conclusions This is the first demonstration of OCTA in iris tumors. OCTA may provide a dye-free, no

  8. Enhanced spectral domain optical coherence tomography for pathological and functional studies

    Science.gov (United States)

    Yuan, Zhijia

    Optical coherence tomography (OCT) is a novel technique that enables noninvasive or minimally invasive, cross-sectional imaging of biological tissue at sub-10mum spatial resolution and up to 2-3mm imaging depth. Numerous technological advances have emerged in recent years that have shown great potential to develop OCT into a powerful imaging and diagnostic tools. In particular, the implementation of Fourier-domain OCT (FDOCT) is a major step forward that leads to greatly improved imaging rate and image fidelity of OCT. This dissertation summarizes the work that focuses on enhancing the performances and functionalities of spectral radar based FDOCT (SDOCT) for pathological and functional applications. More specifically, chapters 1-4 emphasize on the development of SDOCT and its utility in pathological studies, including cancer diagnosis. The principle of SDOCT is first briefly outlined, followed by the design of our bench-top SDOCT systems with emphasis on spectral linear interpolation, calibration and system dispersion compensation. For ultrahigh-resolution SDOCT, time-lapse image registration and frame averaging is introduced to effectively reduce speckle noise and uncover subcellular details, showing great promise for enhancing the diagnosis of carcinoma in situ. To overcome the image depth limitation of OCT, a dual-modal imaging method combing SDOCT with high-frequency ultrasound is proposed and examined in animal cancer models to enhance the sensitivity and staging capabilities for bladder cancer diagnosis. Chapters 5-7 summarize the work on developing Doppler SDOCT for functional studies. Digital-frequency-ramping OCT (DFR-OCT) is developed in the study, which has demonstrated the ability to significantly improve the signal-to-noise ratio and thus sensitivity for retrieving subsurface blood flow imaging. New DFR algorithms and imaging processing methods are discussed to further enhance cortical CBF imaging. Applications of DFR-OCT for brain functional studies

  9. In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes.

    Science.gov (United States)

    Singh, Kanwarpal; Reddy, Rohith; Sharma, Gargi; Verma, Yogesh; Gardecki, Joseph A; Tearney, Guillermo

    2018-03-01

    Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test the designed probe in a cadaver human coronary artery ex vivo. We achieved a sensitivity of 104 dB for this probe using a swept source optical coherence tomography system. To test the probe, images of a cadaver human coronary artery were obtained, demonstrating the quality that is comparable to those obtained by OCT systems with separate reference arms. Additionally, we demonstrate recovery of ranging depth by use of a Michelson interferometer in the detection path. We developed a miniaturized monolithic inline fiber mirror-based common path probe for optical coherence tomography. Owing to its simplicity, our design will be helpful in endoscopic applications that require high-resolution probes in a compact form factor while reducing system complexity. Lasers Surg. Med. 50:230-235, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema

    International Nuclear Information System (INIS)

    Saraiva, Fabio Petersen; Costa, Patricia Grativol; Inomata, Daniela Lumi; Melo, Carlos Sergio Nascimento; Helal Junior, John; Nakashima, Yoshitaka

    2007-01-01

    Objectives: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. Introduction: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. Methods: The study recruited diabetic patients without clinically evident retinopathy (control group) and with diffuse macular edema (case group). Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. Results: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. Discussion: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. Conclusions: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema. (author)

  11. Fundus autofluorescence and optical coherence tomography of congenital grouped albinotic spots.

    Science.gov (United States)

    Kim, David Y; Hwang, John C; Moore, Anthony T; Bird, Alan C; Tsang, Stephen H

    2010-09-01

    The purpose of this study was to describe the findings of fundus autofluores-cence (FAF) and optical coherence tomography in a series of patients with congenital grouped albinotic spots. Three eyes of three patients with congenital grouped albinotic spots were evaluated with FAF and optical coherence tomography imaging to evaluate the nature of the albinotic spots. In all three eyes with congenital grouped albinotic spots, FAF imaging showed autofluorescent spots corresponding to the albinotic spots seen on stereo biomicroscopy. One eye also had additional spots detected on FAF imaging that were not visible on stereo biomicroscopy or color fundus photographs. Fundus autofluorescence imaging of the spots showed decreased general autofluorescence and decreased peripheral autofluorescence surrounding central areas of retained or increased autofluorescence. Optical coherence tomography showed a disruption in signal from the hyperreflective layer corresponding to the inner and outer segment junction and increased signal backscattering from the choroid in the area of the spots. Fluorescein angiography showed early and stable hyperfluorescence of the spots without leakage. In this case series, FAF showed decreased autofluorescence of the spots consistent with focal retinal pigment epithelium atrophy or abnormal material blocking normal autofluorescence and areas of increased autofluorescence suggesting retinal pigment epithelium dysfunction. The findings of optical coherence tomography and fluorescein angiography suggest photoreceptor and retinal pigment epithelium layer abnormalities. Fundus autofluorescence and optical coherence tomography are useful noninvasive diagnostic adjuncts that can aid in the diagnosis of congenital grouped albinotic spots, help determine extent of disease, and contribute to our understanding of its pathophysiology.

  12. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema

    Energy Technology Data Exchange (ETDEWEB)

    Saraiva, Fabio Petersen; Costa, Patricia Grativol; Inomata, Daniela Lumi; Melo, Carlos Sergio Nascimento; Helal Junior, John; Nakashima, Yoshitaka [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. de Oftalmologia]. E-mail: fabiopetersen@yahoo.com.br

    2007-07-01

    Objectives: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. Introduction: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. Methods: The study recruited diabetic patients without clinically evident retinopathy (control group) and with diffuse macular edema (case group). Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. Results: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. Discussion: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. Conclusions: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema. (author)

  13. INTRASURGICAL MICROSCOPE-INTEGRATED SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-ASSISTED MEMBRANE PEELING.

    Science.gov (United States)

    Falkner-Radler, Christiane I; Glittenberg, Carl; Gabriel, Max; Binder, Susanne

    2015-10-01

    To evaluate microscope-integrated intrasurgical spectral domain optical coherence tomography during macular surgery in a prospective monocenter study. Before pars plana vitrectomy and before, during, and after membrane peeling, 512 × 128 macular cube scans were performed using a Carl Zeiss Meditec Cirrus high-definition OCT system adapted to the optical pathway of a Zeiss OPMI VISU 200 surgical microscope and compared with retinal staining. The study included 51 patients with epiretinal membranes, with 8 of those having additional lamellar macular holes, 11 patients with vitreomacular traction, and 8 patients with full-thickness macular holes. Intraoperative spectral domain optical coherence tomography allowed performing membrane peeling without using retinal dyes in 40% of cases (28 of 70 patients). No residual membranes were found in 94.3% of patients (66 of 70 patients) in intrasurgical spectral domain optical coherence tomography and subsequent (re)staining. In patients with vitreomacular traction, intrasurgical spectral domain optical coherence tomography scans facilitated decisions on the need for an intraocular tamponade after membrane peeling. Intraoperative spectral domain optical coherence tomography was comparable with retinal dyes in confirming success after membrane peeling. However, the visualization of flat membranes was better after staining.

  14. Ceramic and polymeric dental onlays evaluated by photo-elasticity, optical coherence tomography, and micro-computed tomography

    Science.gov (United States)

    Sinescu, Cosmin; Negrutiu, Meda; Topala, Florin; Ionita, Ciprian; Negru, Radu; Fabriky, Mihai; Marcauteanu, Corina; Bradu, Adrian; Dobre, George; Marsavina, Liviu; Rominu, Mihai; Podoleanu, Adrian

    2011-10-01

    Dental onlays are restorations used to repair rear teeth that have a mild to moderate amount of decay. They can also be used to restore teeth that are cracked or fractured if the damage is not severe enough to require a dental crown. The use of onlays requires less tooth reduction than does the use of metal fillings. This allows dentists to conserve more of a patient's natural tooth structure in the treatment process. The aims of this study are to evaluate the biomechanical comportment of the dental onlays, by using the 3D photo elasticity method and to investigate the integrity of the structures and their fitting to the dental support. For this optical coherence tomography and micro-computed tomography were employed. Both methods were used to investigate 37 dental onlays, 17 integral polymeric and 20 integral ceramic. The results permit to observe materials defects inside the ceramic or polymeric onlays situate in the biomechanically tensioned areas that could lead to fracture of the prosthetic structure. Marginal fitting problems of the onlays related to the teeth preparations were presented in order to observe the possibility of secondary cavities. The resulted images from the optical coherence tomography were verified by the micro-computed tomography. In conclusion, the optical coherence tomography can be used as a clinical method in order to evaluate the integrity of the dental ceramic and polymeric onlays and to investigate the quality of the marginal fitting to the teeth preparations.

  15. In vivo breast sound-speed imaging with ultrasound tomography

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTITUTE; Duric, Neb [KARMANOS CANCER INSTITUTE; Littrup, Peter [KARMONOS CANCER INSTITUTE

    2009-01-01

    We discuss a bent-ray ultrasound tomography algorithm with total-variation (TV) regularization. We have applied this algorithm to 61 in vivo breast datasets collected with our in-house clinical prototype for imaging sound-speed distributions in the breast. Our analysis showed that TV regularization could preserve sharper lesion edges than the classic Tikhonov regularization. Furthermore, the image quality of our TV bent-ray sound-speed tomograms was superior to that of the straight-ray counterparts for all types of breasts within BI-RADS density categories 1-4. For all four breast types from fatty to dense, the improvements for average sharpness (in the unit of (m{center_dot} s) {sup -1}) of lesion edges in our TV bent-ray tomograms are between 2.1 to 3.4 fold compared to the straight ray tomograms. Reconstructed sound-speed tomograms illustrated that our algorithm could successfully image fatty and glandular tissues within the breast. We calculated the mean sound-speed values for fatty tissue and breast parenchyma as 1422 {+-} 9 mls (mean{+-} SD) and1487 {+-} 21 mls, respectively. Based on 32 lesions in a cohort of 61 patients, we also found that the mean sound-speed for malignant breast lesions (1548{+-}17 mls) was higher, on average, than that of benign ones (1513{+-}27 mls) (one-sided p

  16. Computed tomography and ultrasound in parapneumonic effusions and empyema

    Energy Technology Data Exchange (ETDEWEB)

    Kearney, S.E.; Davies, C.W.H.; Davies, R.J.O.; Gleeson, F.V

    2000-07-01

    AIM: Imaging of pleural empyema by ultrasound (US) or computed tomography (CT) is used to confirm the diagnosis and facilitate drainage. However, the information gained from US and CT may also have prognostic significance. The aim of the present study was to determine if CT and US appearances correlated with the severity of infection as determined by established microbiological and biochemical indicators, and to establish whether either technique could predict those patients who will fail drainage and require surgery. MATERIALS AND METHODS: Fifty patients with parapneumonic effusions were assessed. All had thoracic CT and the results of thoracic US were available in 36 patients. Imaging features were compared to the stage of the effusion and clinical outcome. RESULTS: At US, 7/36 (19%) pleural collections were anechoic, 5/36 (14%) were hyperechoic without septae and 24/36 (67%) were hyperechoic with septae. There was no relationship between US appearances and the presence of pus, the effusion stage or the need for surgical treatment. On CT pleural enhancement was seen in all patients. There was evidence of pleural thickening in 46/50 (92%) and thickening of extrapleural fat in 38/50 (76%). There was a trend for mean pleural thickness to increase with an increasing stage of pleural infection. However, a wide range of appearances were seen and overall the thickness of pleural/extrapleural tissues was not significantly related to the stage of effusion or to the requirement for surgery. CONCLUSIONS: Although US and CT have established roles in the investigation of parapneumonic effusions, neither technique reliably identifies the stage of pleural infection or predicts those patients who subsequently require surgical intervention after failed management by chest tube drainage and intrapleural fibrinolytics. Kearney, S.E. (2000)

  17. Computed tomography and ultrasound in parapneumonic effusions and empyema

    International Nuclear Information System (INIS)

    Kearney, S.E.; Davies, C.W.H.; Davies, R.J.O.; Gleeson, F.V.

    2000-01-01

    AIM: Imaging of pleural empyema by ultrasound (US) or computed tomography (CT) is used to confirm the diagnosis and facilitate drainage. However, the information gained from US and CT may also have prognostic significance. The aim of the present study was to determine if CT and US appearances correlated with the severity of infection as determined by established microbiological and biochemical indicators, and to establish whether either technique could predict those patients who will fail drainage and require surgery. MATERIALS AND METHODS: Fifty patients with parapneumonic effusions were assessed. All had thoracic CT and the results of thoracic US were available in 36 patients. Imaging features were compared to the stage of the effusion and clinical outcome. RESULTS: At US, 7/36 (19%) pleural collections were anechoic, 5/36 (14%) were hyperechoic without septae and 24/36 (67%) were hyperechoic with septae. There was no relationship between US appearances and the presence of pus, the effusion stage or the need for surgical treatment. On CT pleural enhancement was seen in all patients. There was evidence of pleural thickening in 46/50 (92%) and thickening of extrapleural fat in 38/50 (76%). There was a trend for mean pleural thickness to increase with an increasing stage of pleural infection. However, a wide range of appearances were seen and overall the thickness of pleural/extrapleural tissues was not significantly related to the stage of effusion or to the requirement for surgery. CONCLUSIONS: Although US and CT have established roles in the investigation of parapneumonic effusions, neither technique reliably identifies the stage of pleural infection or predicts those patients who subsequently require surgical intervention after failed management by chest tube drainage and intrapleural fibrinolytics. Kearney, S.E. (2000)

  18. Multiple Scattering Model for Optical Coherence Tomography with Rytov Approximation

    KAUST Repository

    Li, Muxingzi

    2017-01-01

    of speckles due to multiple scatterers within the coherence length, and other random noise. Motivated by the above two challenges, a multiple scattering model based on Rytov approximation and Gaussian beam optics is proposed for the OCT setup. Some previous

  19. Autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytoma.

    Science.gov (United States)

    Guerra, Ricardo Luz Leitão; Marback, Eduardo Ferrari; Silva, Igor Sandes Pessoa da; Maia Junior, Otacílio de Oliveira; Marback, Roberto Lorens

    2014-01-01

    The authors report fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (OCT) findings of two consecutive patients who presented with optic disk melanocytoma (ODM). A retrospective study was performed by reviewing medical records and ophthalmic imaging examinations. Optical coherence tomography findings were sloped and brightly reflective anterior tumor surface, adjacent retinal desorganization and abrupt posterior optical shadowing. Vitreous seeds were found in one patient. Fundus autofluorescence revealed outstanding hypoautofluorescence at the tumor area and isoautofluorescence at the remaining retina. Optical coherence tomography findings of the reported cases are consistent with those reported in the reviewed literature. Fundus autofluorescence has been used in the assessment of choroidal melanocytic tumors, but not yet in melanocytomas. We assume that this is the first report of these findings and believe that when its pattern has become clearly defined, fundus autofluorescence will be a useful tool to avoid misdiagnosis in suspicious cases and for follow-up.

  20. Autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytoma

    Directory of Open Access Journals (Sweden)

    Ricardo Luz Leitão Guerra

    2014-12-01

    Full Text Available The authors report fundus autofluorescence (FAF and spectral-domain optical coherence tomography (OCT findings of two consecutive patients who presented with optic disk melanocytoma (ODM. A retrospective study was performed by reviewing medical records and ophthalmic imaging examinations. Optical coherence tomography findings were sloped and brightly reflective anterior tumor surface, adjacent retinal desorganization and abrupt posterior optical shadowing. Vitreous seeds were found in one patient. Fundus autofluorescence revealed outstanding hypoautofluorescence at the tumor area and isoautofluorescence at the remaining retina. Optical coherence tomography findings of the reported cases are consistent with those reported in the reviewed literature. Fundus autofluorescence has been used in the assessment of choroidal melanocytic tumors, but not yet in melanocytomas. We assume that this is the first report of these findings and believe that when its pattern has become clearly defined, fundus autofluorescence will be a useful tool to avoid misdiagnosis in suspicious cases and for follow-up.

  1. Imaging actinic keratosis by high-definition optical coherence tomography. Histomorphologic correlation

    DEFF Research Database (Denmark)

    Boone, Marc A L M; Norrenberg, Sarah; Jemec, Gregor B E

    2013-01-01

    With the continued development of non-invasive therapies for actinic keratosis such as PDT and immune therapies, the non-invasive diagnosis and monitoring become increasingly relevant. High-definition optical coherence tomography is a high-resolution imaging tool, with micrometre resolution in both...... transversal and axial directions, enable to visualize individual cells up to a depth of around 570 μm filling the imaging gap between conventional optical coherence tomography and reflectance confocal microscopy. We sought to determine the feasibility of detecting and grading of actinic keratosis...... by this technique using criteria defined for reflectance confocal microscopy compared to histology. In this pilot study, skin lesions of 17 patients with a histologically proven actinic keratosis were imaged by high-definition optical coherence tomography just before excision and images analysed qualitatively...

  2. Optical coherence tomography imaging of chorioretinal folds associated with hypotony maculopathy following pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Williams Jr BK

    2015-09-01

    Full Text Available Basil K Williams Jr, Jonathan S Chang, Harry W Flynn Jr Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Abstract: Chorioretinal folds may occur as a consequence of hypotony and can be a cause of vision loss when associated with macular involvement. In this report, the spectral domain ocular coherence tomography imaging of three patients with chorioretinal folds before and after management are presented. The cases had unique presentations and each underwent different management approaches, but the results included improved visual acuities and lessened chorioretinal folds. Keywords: hypotony, chorioretinal folds, ocular coherence tomography

  3. The collagen structure of equine articular cartilage, characterized using polarization-sensitive optical coherence tomography

    International Nuclear Information System (INIS)

    Ugryumova, Nadya; Attenburrow, Don P; Winlove, C Peter; Matcher, Stephen J

    2005-01-01

    Optical coherence tomography and polarization-sensitive optical coherence tomography images of equine articular cartilage are presented. Measurements were made on intact joint surfaces. Significant (e.g. x 2) variations in the intrinsic birefringence were found over spatial scales of a few millimetres, even on samples taken from young (18 month) animals that appeared visually homogeneous. A comparison of data obtained on a control tissue (equine flexor tendon) further suggests that significant variations in the orientation of the collagen fibres relative to the plane of the joint surface exist. Images of visually damaged cartilage tissue show characteristic features both in terms of the distribution of optical scatterers and of the birefringent components

  4. The collagen structure of equine articular cartilage, characterized using polarization-sensitive optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ugryumova, Nadya; Attenburrow, Don P; Winlove, C Peter; Matcher, Stephen J [Biomedical Physics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)

    2005-08-07

    Optical coherence tomography and polarization-sensitive optical coherence tomography images of equine articular cartilage are presented. Measurements were made on intact joint surfaces. Significant (e.g. x 2) variations in the intrinsic birefringence were found over spatial scales of a few millimetres, even on samples taken from young (18 month) animals that appeared visually homogeneous. A comparison of data obtained on a control tissue (equine flexor tendon) further suggests that significant variations in the orientation of the collagen fibres relative to the plane of the joint surface exist. Images of visually damaged cartilage tissue show characteristic features both in terms of the distribution of optical scatterers and of the birefringent components.

  5. Optical coherence tomography of the preterm eye: from retinopathy of prematurity to brain development

    Science.gov (United States)

    Rothman, Adam L; Mangalesh, Shwetha; Chen, Xi; Toth, Cynthia A

    2016-01-01

    Preterm infants with retinopathy of prematurity are at increased risk of poor neurodevelopmental outcomes. Because the neurosensory retina is an extension of the central nervous system, anatomic abnormalities in the anterior visual pathway often relate to system and central nervous system health. We describe optical coherence tomography as a powerful imaging modality that has recently been adapted to the infant population and provides noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside. Optical coherence tomography has increased understanding of normal eye development and has identified several potential biomarkers of brain abnormalities and poorer neurodevelopment. PMID:28539807

  6. Optical coherence tomography in otolaryngology: original results and review of the literature

    Science.gov (United States)

    Bibas, Athanasios G.; Podoleanu, Adrian Gh.; Cucu, Radu G.; Dobre, George M.; Odell, Edward; Boxer, Aaron B.; O'Connors, Alec F.; Gleeson, Michael J.

    2004-07-01

    Optical coherence tomography is a diagnostic imaging technique allowing two dimensional tomographic imaging of tissue architecture. This is a review article on the use of optical coherence tomography in Otolaryngology including original images from human laryngeal tissue and temporal bones (cochlea) in our laboratory. Tissue specimens from normal larynges were imaged with an 850 nm OCT system. Our results showed good correlation between OCT image s and the corresponding haematoxylin-eosin stained histology sections in the normal larynx. Human temporal bones were also imaged using an 1300 nm OCT system. Limited morphological details were obtained due to the high scattering properties of the bony labyrinth.

  7. Contribution of optical coherence tomography imaging in management of iatrogenic coronary dissection

    Energy Technology Data Exchange (ETDEWEB)

    Barber-Chamoux, Nicolas, E-mail: nbarber-chamoux@chu-clermontferrand.fr [Department of Cardiology, Gabriel Montpied University Hospital, Clermont-Ferrand (France); Souteyrand, Géraud; Combaret, Nicolas [Department of Cardiology, Gabriel Montpied University Hospital, Clermont-Ferrand (France); ISIT, CaVITI, CNRS (UMR-6284), Auvergne University, Clermont-Ferrand (France); Ouedraogo, Edgar; Lusson, Jean René [Department of Cardiology, Gabriel Montpied University Hospital, Clermont-Ferrand (France); Motreff, Pascal [Department of Cardiology, Gabriel Montpied University Hospital, Clermont-Ferrand (France); ISIT, CaVITI, CNRS (UMR-6284), Auvergne University, Clermont-Ferrand (France)

    2016-03-15

    Iatrogenic coronary dissection is a rare but potentially serious complication of coronary angiography and angioplasty. Treatment with angioplasty guided only by angiography is often difficult. Optical coherence tomography imaging seems to be an interesting technique to lead the management of iatrogenic coronary dissection. Diagnosis can be made by optical coherence tomography; it can also eliminate differential diagnosis. Furthermore, this technique can guide safely the endovascular treatment. - Highlights: • Iatrogenic coronary dissection remains a challenging problem in angiography. • Endocoronary imaging is helpful for the diagnosis of iatrogenic coronary dissection. • OCT is a safe option to manage the endovascular treatment of coronary dissection.

  8. Improved Plane-Wave Ultrasound Beamforming by Incorporating Angular Weighting and Coherent Compounding in Fourier Domain.

    Science.gov (United States)

    Chen, Chuan; Hendriks, Gijs A G M; van Sloun, Ruud J G; Hansen, Hendrik H G; de Korte, Chris L

    2018-05-01

    In this paper, a novel processing framework is introduced for Fourier-domain beamforming of plane-wave ultrasound data, which incorporates coherent compounding and angular weighting in the Fourier domain. Angular weighting implies spectral weighting by a 2-D steering-angle-dependent filtering template. The design of this filter is also optimized as part of this paper. Two widely used Fourier-domain plane-wave ultrasound beamforming methods, i.e., Lu's f-k and Stolt's f-k methods, were integrated in the framework. To enable coherent compounding in Fourier domain for the Stolt's f-k method, the original Stolt's f-k method was modified to achieve alignment of the spectra for different steering angles in k-space. The performance of the framework was compared for both methods with and without angular weighting using experimentally obtained data sets (phantom and in vivo), and data sets (phantom) provided by the IEEE IUS 2016 plane-wave beamforming challenge. The addition of angular weighting enhanced the image contrast while preserving image resolution. This resulted in images of equal quality as those obtained by conventionally used delay-and-sum (DAS) beamforming with apodization and coherent compounding. Given the lower computational load of the proposed framework compared to DAS, to our knowledge it can, therefore, be concluded that it outperforms commonly used beamforming methods such as Stolt's f-k, Lu's f-k, and DAS.

  9. Precision of high definition spectral-domain optical coherence tomography for measuring central corneal thickness.

    Science.gov (United States)

    Correa-Pérez, María E; López-Miguel, Alberto; Miranda-Anta, Silvia; Iglesias-Cortiñas, Darío; Alió, Jorge L; Maldonado, Miguel J

    2012-04-06

    This study was intended to assess the reliability of central corneal thickness (CCT) measurements using Cirrus high-definition optical coherence tomography (HD-OCT) in healthy subjects and its accuracy compared with ultrasonic pachymetry. Seventy-seven consecutive subjects were recruited for evaluating repeatability, and agreement between two examiners. To analyze repeatability, one examiner measured 77 eyes four times in succession. To study agreement between two observers, a second independently trained examiner obtained another CCT measurement. We also measured eyes in a subgroup of 20 patients using standard ultrasonic pachymetry. Within-subject standard deviation (S(w)), coefficient of variation (CV), limits of agreement (LoA), and intraclass correlation coefficient (ICC) data were obtained. For repeatability, the S(w) and precision (1.96 × S(w)) were 4.86 and 9.52 μm, respectively. Intraobserver CV was 0.89% and the ICC was 0.98 (95% confidence interval [CI], 0.97-0.99). For agreement between two examiners, the S(w) and precision were 7.58 and 14.85 μm, respectively; the CV was 1.40%. The mean difference between observers was -0.13 μm (95% CI, -1.85 to 1.58; P = 0.87). The width of the LoA was 29.64 μm. Median difference between Cirrus HD-OCT and ultrasound CCT measurements was -4.5 μm (interquartile range, -7.0-0.0; P = 0.04). Cirrus HD-OCT provides repeatable CCT measurements, good agreement between two independently trained examiners, and its systematic bias compared to ultrasonic pachymetry is clinically negligible. Therefore, research laboratories and eye clinics using Cirrus HD-OCT as a diagnostic imaging method, can also benefit from a reliable noncontact pachymeter when counseling patients with glaucoma and those undergoing corneal and refractive surgeries.

  10. Simple balloon dilation for drug-eluting in-stent restenosis: An optical coherent tomography analysis

    Energy Technology Data Exchange (ETDEWEB)

    Arikawa, Ryo [Division of Cardiology, Tenyoukai Central Hospital, Izumi-cho, Kagoshima City, Kagoshima (Japan); Yamaguchi, Hiroshi, E-mail: hyamaguchi@tsm.bbiq.jp [Division of Cardiology, Tenyoukai Central Hospital, Izumi-cho, Kagoshima City, Kagoshima (Japan); Takaoka, Junichiro; Miyamura, Akihiro; Atsuchi, Nobuhiko; Ninomiya, Toshiko; Atsuchi, Yoshihiko [Division of Cardiology, Tenyoukai Central Hospital, Izumi-cho, Kagoshima City, Kagoshima (Japan); Ohishi, Mitsuru [Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima (Japan); Terashima, Mitsuyasu [Department of Cardiology, Toyohashi Heart Center, Toyohashi (Japan); Kaneda, Hideaki [Okinaka Memorial Institute for Medical Research, Tokyo (Japan)

    2015-01-15

    Background: Although drug-eluting stent (DES) has significantly reduced restenosis, the treatment of DES-in-stent restenosis (ISR) remains a challenge with high restenosis rate. Methods: We examined whether morphologic appearance of restenosis tissue by optical coherent tomography (OCT) had an impact on outcomes after balloon angioplasty for DES-ISR. The morphologic appearance of restenosis tissue was qualitatively assessed for tissue structures such as homogeneous, layered, and heterogeneous patterns. Results: Using OCT, 50 patients with DES-ISR were divided into 2 groups: 25 lesions with homogeneous or layered patterns (homo/layered group) and 25 lesions with heterogeneous patterns (hetero group). Acute gain was larger in the hetero group (1.33 ± 0.41 mm vs. 1.06 ± 0.32 mm in the homo/layered group, P = 0.03). On intravascular ultrasound analysis, post-procedural percent neointimal area was smaller in the hetero group (27.4 ± 9.2% vs. 34.0 ± 11.2% in the homo/layered group, P = 0.05). Angiographic follow-up was performed in 37 lesions (74%). Follow-up minimal lumen diameter was larger in the hetero group (1.75 ± 0.89 mm vs. 1.01 ± 0.81 mm in the homo/layered group, P = 0.04). Target lesion revascularization rates tended to be lower in the hetero group (20% vs. 43% in the homo/layered group, P = 0.12). Conclusions: Balloon angioplasty was more effective for DES-ISR with heterogeneous tissue appearance than DES-ISR with homogeneous/layered tissue appearance. OCT assessment of DES-ISR morphology may be a useful adjunct in determining clinical strategies. Simple balloon dilatation is a possible treatment strategy for DES-ISR lesions with a heterogeneous appearance on OCT images.

  11. Contrast generation in the nuclear-spin tomography by pulsed ultrasound

    International Nuclear Information System (INIS)

    Oehms, Ole Benjamin

    2009-01-01

    In the framework of this thesis a combined method of ultrasound and nuclear-spin tomography is presented. Via ultrasound pulses by the sound-radiation force in liquids and tissue phantoms motions are generated, which depend on ther viscoelastic properties. This motions are made visible by a motion-sensitive tomograph sequence in the phase image of the tomograph in form of a phase change. The first measurements on simple phantoms and liquids are presented. [de

  12. Breast ultrasound tomography: bridging the gap to clinical practice

    Science.gov (United States)

    Duric, Neb; Littrup, Peter; Li, Cuiping; Roy, Olivier; Schmidt, Steven; Janer, Roman; Cheng, Xiaoyang; Goll, Jeffrey; Rama, Olsi; Bey-Knight, Lisa; Greenway, William

    2012-03-01

    Conventional sonography, which performs well in dense breast tissue and is comfortable and radiation-free, is not practical for screening because of its operator dependence and the time needed to scan the whole breast. While magnetic resonance imaging (MRI) can significantly improve on these limitations, it is also not practical because it has long been prohibitively expensive for routine use. There is therefore a need for an alternative breast imaging method that obviates the constraints of these standard imaging modalities. The lack of such an alternative is a barrier to dramatically impacting mortality (about 45,000 women in the US per year) and morbidity from breast cancer because, currently, there is a trade-off between the cost effectiveness of mammography and sonography on the one hand and the imaging accuracy of MRI on the other. This paper presents a progress report on our long term goal to eliminate this trade-off and thereby improve breast cancer survival rates and decrease unnecessary biopsies through the introduction of safe, cost-effective, operatorindependent sonography that can rival MRI in accuracy. The objective of the study described in this paper was to design and build an improved ultrasound tomography (UST) scanner in support of our goals. To that end, we report on a design that builds on our current research prototype. The design of the new scanner is based on a comparison of the capabilities of our existing prototype and the performance needed for clinical efficacy. The performance gap was quantified by using clinical studies to establish the baseline performance of the research prototype, and using known MRI capabilities to establish the required performance. Simulation software was used to determine the basic operating characteristics of an improved scanner that would provide the necessary performance. Design elements focused on transducer geometry, which in turn drove the data acquisition system and the image reconstruction engine

  13. Comparative study of ultrasound imaging, computed tomography and magnetic resonance imaging in gynecology

    International Nuclear Information System (INIS)

    Ishii, Kenji; Kobayashi, Hisaaki; Hoshihara, Takayuki; Kobayashi, Mitsunao; Suda, Yoshio; Takenaka, Eiichi; Sasa, Hidenori.

    1989-01-01

    We studied 18 patients who were operated at the National Defense Medical College Hospital and confirmed by pathological diagnosis. We compared ultrasound imaging, computed tomography (CT) and magnetic resonance imaging (MRI) of the patients. MRI was useful to diagnose enlargement of the uterine cavity and a small amount of ascites and to understand orientation of the pelvic organs. Ultrasound imaging is the most useful examination to diagnose gynecological diseases. But when it is difficult to diagnose by ultrasound imaging alone, we should employ either CT or MRI, or preferably both. (author)

  14. Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic

    Directory of Open Access Journals (Sweden)

    Megan M. Leo

    2017-05-01

    Full Text Available Introduction: Supporting an “ultrasound-first” approach to evaluating renal colic in the emergency department (ED remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP ultrasound to computed tomography (CT detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. Methods: This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. Results: We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis ( x 2=51.7, p5mm less likely (NPV 89%; LR− 0.39. Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03. Conclusion: Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

  15. Flow patterns on spectral-domain optical coherence tomography reveal flow directions at retinal vessel bifurcations

    DEFF Research Database (Denmark)

    Willerslev, Anne; Li, Xiao Q; Munch, Inger C

    2014-01-01

    PURPOSE: To study intravascular characteristics of flowing blood in retinal vessels using spectral-domain optical coherence tomography (SD-OCT). METHODS: Examination of selected arterial bifurcations and venous sites of confluence in 25 healthy 11-year-old children recruited as an ad hoc subsample...

  16. Measurement of biofilm growth and local hydrodynamics using optical coherence tomography

    NARCIS (Netherlands)

    Weiss, Nicolas; El Tayeb El Obied, Khalid; Kalkman, Jeroen; Lammertink, Rob G.H.; van Leeuwen, Ton G.

    2016-01-01

    We report on localized and simultaneous measurement of biofilm growth and local hydrodynamics in a microfluidic channel using optical coherence tomography. We measure independently with high spatio-temporal resolution the longitudinal flow velocity component parallel to the imaging beam and the

  17. Broadband Fourier domain mode-locked laser for optical coherence tomography at 1060 nm

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang

    2012-01-01

    Optical coherence tomography (OCT) in the 1060nm range is interesting for in vivo imaging of the human posterior eye segment (retina, choroid, sclera) due to low absorption in water and deep penetration into the tissue. Rapidly tunable light sources, such as Fourier domain mode-locked (FDML) lasers...

  18. Towards spectral-domain optical coherence tomography on a silicon chip

    NARCIS (Netherlands)

    Akça, B.I.; Worhoff, Kerstin; Nguyen, V.D.; Kalkman, J.; van Leeuwen, Ton; de Ridder, R.M.; Pollnau, Markus

    Optical coherence tomography (OCT) is a widely used optical imaging technology, particularly in the medical field, since it can provide non-invasive, sub-micrometer resolution diagnostic images of tissue. Current OCT systems contain optical fibers and free-space optical components which make these

  19. Histologic correlation of in vivo optical coherence tomography images of the human retina

    NARCIS (Netherlands)

    Chen, T.; Cense, B.; Miller, J.S.; Rubin, P. A. D.; Deschler, D. G.; Gragoudas, E. S.; de Boer, J.F.

    2006-01-01

    Purpose: To correlate in vivo human retina optical coherence tomography (OCT)3 images with histology. Design: Case series. Methods: Linear OCT3 scans through the macula and optic nerve were obtained in three eyes of three patients who then underwent exenteration surgery for orbital cancers. OCT3

  20. Volume determination of fresh and dried bloodstains by means of optical coherence tomography

    NARCIS (Netherlands)

    Laan, Nick; Bremmer, Rolf H.; Aalders, Maurice C. G.; de Bruin, Karla G.

    2014-01-01

    The volume of bloodstains found on crime scenes may help forensic investigators reconstruct the location and kinematics of bloodletting events, as stain size, volume, and impact velocity are related. Optical coherence tomography was used as a method to determine the volume and volume ratio of dried

  1. Extracting structural features of rat sciatic nerve using polarization-sensitive spectral domain optical coherence tomography

    NARCIS (Netherlands)

    Islam, M.S.; Oliveira, M.C.; Wang, Y.; Henry, F.P.; Randolph, M.A.; Park, B. H.; de Boer, J.F.

    2012-01-01

    We present spectral domain polarization-sensitive optical coherence tomography (SD PS-OCT) imaging of peripheral nerves. Structural and polarization-sensitive OCT imaging of uninjured rat sciatic nerves was evaluated both qualitatively and quantitatively. OCT and its functional extension, PS-OCT,

  2. Spectral shaping for non-Gaussian source spectra in optical coherence tomography

    NARCIS (Netherlands)

    Tripathi, R; Nassif, N. A.; Nelson, JS; Park, B.H.; de Boer, JF

    2002-01-01

    We present a digital spectral shaping technique to reduce the sidelobes (ringing) of the axial point-spread function in optical coherence tomography for non-Gaussian-shaped source spectra. The spectra of two superluminescent diodes were combined to generate a spectrum with significant modulation.

  3. Frequency-swept Light Sources for Optical Coherence Tomography in the 1060nm range

    DEFF Research Database (Denmark)

    Marschall, Sebastian

    Optical coherence tomography (OCT) is a non-invasive imaging technique for visualizing the internal structure of scattering materials, such as biological tissues. It generates two- or three-dimensional images of the sample with cellular (micrometer) resolution. OCT has become an important instrum...

  4. Online monitoring of printed electronics by Spectral-Domain Optical Coherence Tomography

    KAUST Repository

    Alarousu, Erkki; Alsaggaf, Ahmed; Jabbour, Ghassan E.

    2013-01-01

    Spectral-Domain Optical Coherence Tomography (SD-OCT) is an optical method capable of 3D imaging of object's internal structure with micron-scale resolution. Modern SD-OCT tools offer the speed capable of online monitoring of printed devices

  5. Near-infrared optical coherence tomography for the inspection of fiber composites

    NARCIS (Netherlands)

    Liu, P.; Yao, L.; Groves, R.M.

    2015-01-01

    Optical coherence tomography (OCT) is a non-invasive imaging method, which allows the econstruction of three dimensional depth-resolved images with microscale resolution. Originally developed for biomedical diagnostics, nowadays it also shows a high potential for applications in the field of

  6. Derivation of a Monte Carlo method for modeling heterodyne detection in optical coherence tomography systems

    DEFF Research Database (Denmark)

    Tycho, Andreas; Jørgensen, Thomas Martini; Andersen, Peter E.

    2002-01-01

    A Monte Carlo (MC) method for modeling optical coherence tomography (OCT) measurements of a diffusely reflecting discontinuity emb edded in a scattering medium is presented. For the first time to the authors' knowledge it is shown analytically that the applicability of an MC approach to this opti...

  7. Clinical experiences with optical coherence tomography in epithelial (pre)malignancies

    NARCIS (Netherlands)

    Wessels, R.

    2015-01-01

    This thesis describes the potential of optical coherence tomography (OCT) to differentiate between normal tissue and (pre)malignant tissue in epithelial cancers. It can be divided in research performed in the genital area and the field of melanoma. Chapter 2 describes the principles of the

  8. Performance analysis of a hybrid fingerprint extracted from optical coherence tomography fingertip scans

    CSIR Research Space (South Africa)

    Darlow, Luke N

    2016-06-01

    Full Text Available The Hybrid fingerprint is a local-quality-specific blend of the surface and internal fingerprints, extracted from optical coherence tomography scans. Owing to its origin, and the manner in which it is obtained, the Hybrid fingerprint is a high...

  9. High resolution feature extraction from optical coherence tomography acquired internal fingerprint

    CSIR Research Space (South Africa)

    Khutlang, Rethabile

    2016-05-01

    Full Text Available coherence tomography (OCT) can be used to scan the internal skin features, up to the depth of the papillary layer. OCT is contactless and scans in three dimensions. The papillary contour represents an internal fingerprint, which does not suffer external skin...

  10. Novelty detection-based internal fingerprint segmentation in optical coherence tomography images

    CSIR Research Space (South Africa)

    Khutlang, Rethabile

    2017-08-01

    Full Text Available present an automatic segmentation of the papillary layer method, from images acquired using contact-less 3-D swept source optical coherence tomography (OCT). The papillary contour represents the internal fingerprint, which does not suffer from the external...

  11. Retinal nerve fiber layer thickness map determined from optical coherence tomography images

    NARCIS (Netherlands)

    Mujat, M.; Chan, R. C.; Cense, B.; Park, B.H.; Joo, C.; Akkin, T.; Chen, TC; de Boer, JF

    2005-01-01

    We introduce a method to determine the retinal nerve fiber layer (RNFL) thickness in OCT images based on anisotropic noise suppression and deformable splines. Spectral-Domain Optical Coherence Tomography (SDOCT) data was acquired at 29 kHz A-line rate with a depth resolution of 2.6 mum and a depth

  12. Celebrating the Year of Light….. from medicine to security with Optical Coherence Tomography

    CSIR Research Space (South Africa)

    Singh, A

    2015-10-01

    Full Text Available medicine to security with Optical Coherence Tomography Ann Singh1, Ameeth Sharma1, Ted Roberts1, Rethabile Khutlang2, Rocky Ramokolo1, Nico Marome1, Leandra Webb2, Natasha Botha2,Aletta Karsten3, Hencharl Strauss1 1 CSIR, National Laser Centre, P.O Box...

  13. Novelty detection-based internal fingerprint segmentation in optical coherence tomography images

    CSIR Research Space (South Africa)

    Khutlang, R

    2014-12-01

    Full Text Available present an automatic segmentation of the papillary layer method, in 3-D swept source optical coherence tomography (SS-OCT) images. The papillary contour represents the internal fingerprint, which does not suffer external skin problems. The slices composing...

  14. Optical coherence tomography imaging of psoriasis vulgaris: correlation with histology and disease severity

    DEFF Research Database (Denmark)

    Morsy, Hanan; Kamp, Søren; Thrane, Lars

    2010-01-01

    Epidermal thickness (ET) has been suggested as a surrogate measure of psoriasis severity. Optical coherence tomography (OCT) is a recent imaging technology that provides real-time skin images to a depth of 1.8 mm with a micrometre resolution. OCT may provide an accurate in vivo measure of ET. It ...

  15. Quantitative comparison of analysis methods for spectroscopic optical coherence tomography: reply to comment

    NARCIS (Netherlands)

    Bosschaart, Nienke; van Leeuwen, Ton; Aalders, Maurice C.G.; Faber, Dirk

    2014-01-01

    We reply to the comment by Kraszewski et al on “Quantitative comparison of analysis methods for spectroscopic optical coherence tomography.” We present additional simulations evaluating the proposed window function. We conclude that our simulations show good qualitative agreement with the results of

  16. Vascular Tissue Reaction to Acute Malapposition in Human Coronary Arteries Sequential Assessment With Optical Coherence Tomography

    NARCIS (Netherlands)

    Gutiérrez-Chico, Juan Luis; Wykrzykowska, Joanna; Nüesch, Eveline; van Geuns, Robert Jan; Koch, Karel T.; Koolen, Jacques J.; Di Mario, Carlo; Windecker, Stephan; van Es, Gerrit-Anne; Gobbens, Pierre; Jüni, Peter; Regar, Evelyn; Serruys, Patrick W.

    2012-01-01

    Background-The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing. Methods and Results-Optical coherence tomography studies of 66

  17. Vascular tissue reaction to acute malapposition in human coronary arteries sequential assessment with optical coherence tomography

    NARCIS (Netherlands)

    J.L. Gutiérrez-Chico; J.J. Wykrzykowska (Joanna); E. Nüesch (Eveline); R.J.M. van Geuns (Robert Jan); K. Koch (Karel); J.J. Koolen (Jacques); C. di Mario (Carlo); S.W. Windecker (Stephan); G.A. van Es (Gerrit Anne); P. Gobbens (Pierre); P. Jüni (Peter); E.S. Regar (Eveline); P.W.J.C. Serruys (Patrick)

    2012-01-01

    textabstractBackground-The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing. Methods and Results-Optical coherence tomography

  18. An elegant technique for ex vivo imaging in experimental research—Optical coherence tomography (OCT)

    DEFF Research Database (Denmark)

    Tschernig, T.; Thrane, Lars; Jørgensen, Thomas Martini

    2013-01-01

    Optical coherence tomography (OCT) is an elegant technology for imaging of tissues and organs and has been established for clinical use for around a decade. Thus, it is used in vivo but can also serve as a valuable ex vivo imaging tool in experimental research. Here, a brief overview is given...

  19. A prospective, comparative, observational study on optical coherence tomography of the anterior eye segment

    NARCIS (Netherlands)

    Theelen, T.; Hoyng, C.B.

    2013-01-01

    BACKGROUND: We compared two commercially available spectral-domain optical coherence tomography (OCT) devices according to their capacity of imaging the anterior segment of the eye with the same detail and quality. METHODS: A prospective, observational, single-visit study with individuals aged 18

  20. A pilot study on slit lamp-adapted optical coherence tomography imaging of trabeculectomy filtering blebs.

    NARCIS (Netherlands)

    Theelen, T.; Wesseling, P.; Keunen, J.E.E.; Klevering, B.J.

    2007-01-01

    BACKGROUND: Our study aims to identify anatomical characteristics of glaucoma filtering blebs by means of slit lamp-adapted optical coherence tomography (SL-OCT) and to identify new parameters for the functional prognosis of the filter in the early post-operative period. METHODS: Patients with

  1. Optical coherence tomography as an accurate inspection and quality evaluation technique in paper industry

    Science.gov (United States)

    Prykäri, Tuukka; Czajkowski, Jakub; Alarousu, Erkki; Myllylä, Risto

    2010-05-01

    Optical coherence tomography (OCT), a technique for the noninvasive imaging of turbid media, based on low-coherence interferometry, was originally developed for the imaging of biological tissues. Since the development of the technique, most of its applications have been related to the area of biomedicine. However, from early stages, the vertical resolution of the technique has already been improved to a submicron scale. This enables new possibilities and applications. This article presents the possible applications of OCT in paper industry, where submicron or at least a resolution close to one micron is required. This requirement comes from the layered structure of paper products, where layer thickness may vary from single microns to tens of micrometers. This is especially similar to the case with high-quality paper products, where several different coating layers are used to obtain a smooth surface structure and a high gloss. In this study, we demonstrate that optical coherence tomography can be used to measure and evaluate the quality of the coating layer of a premium glossy photopaper. In addition, we show that for some paper products, it is possible to measure across the entire thickness range of a paper sheet. Furthermore, we suggest that in addition to topography and tomography images of objects, it is possible to obtain information similar to gloss by tracking the magnitude of individual interference signals in optical coherence tomography.

  2. Doppler optical coherence microscopy and tomography applied to inner ear mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Page, Scott; Freeman, Dennis M. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Ghaffari, Roozbeh [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States)

    2015-12-31

    While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.

  3. CAPILLARY NETWORK ANOMALIES IN BRANCH RETINAL VEIN OCCLUSION ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

    Science.gov (United States)

    Rispoli, Marco; Savastano, Maria Cristina; Lumbroso, Bruno

    2015-11-01

    To analyze the foveal microvasculature features in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography angiography based on split spectrum amplitude decorrelation angiography technology. A total of 10 BRVO eyes (mean age 64.2 ± 8.02 range between 52 years and 76 years) were evaluated by optical coherence tomography angiography (XR-Avanti; Optovue). The macular angiography scan protocol covered a 3 mm × 3 mm area. The focus of angiography analysis were two retinal layers: superficial vascular network and deep vascular network. The following vascular morphological congestion parameters were assessed in the vein occlusion area in both the superficial and deep networks: foveal avascular zone enlargement, capillary non-perfusion occurrence, microvascular abnormalities appearance, and vascular congestion signs. Image analyses were performed by 2 masked observers and interobserver agreement of image analyses was 0.90 (κ = 0.225, P network of BRVO, a decrease in capillary density with foveal avascular zone enlargement, capillary non-perfusion occurrence, and microvascular abnormalities appearance was observed (P network showed the main vascular congestion at the boundary between healthy and nonperfused retina. Optical coherence tomography angiography in BRVO allows to detect foveal avascular zone enlargement, capillary nonperfusion, microvascular abnormalities, and vascular congestion signs both in the superficial and deep capillary network in all eyes. Optical coherence tomography angiography technology is a potential clinical tool for BRVO diagnosis and follow-up, providing stratigraphic vascular details that have not been previously observed by standard fluorescein angiography. The normal retinal vascular nets and areas of nonperfusion and congestion can be identified at various retinal levels. Optical coherence tomography angiography provides noninvasive images of the retinal capillaries and vascular networks.

  4. method for ranging and noise reduction of low coherence interferometry LCI and optical coherence tomography OCT signals by parallel detection of spectral bands

    NARCIS (Netherlands)

    Boer, JF De; Tearney, G. J.; Bouma, BE

    2008-01-01

    Apparatus and method for increasing the sensitivity in the detection of optical coherence tomography and loW coher ence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source is split

  5. Optical coherence tomography detection of shear wave propagation in inhomogeneous tissue equivalent phantoms and ex-vivo carotid artery samples

    Science.gov (United States)

    Razani, Marjan; Luk, Timothy W.H.; Mariampillai, Adrian; Siegler, Peter; Kiehl, Tim-Rasmus; Kolios, Michael C.; Yang, Victor X.D.

    2014-01-01

    In this work, we explored the potential of measuring shear wave propagation using optical coherence elastography (OCE) in an inhomogeneous phantom and carotid artery samples based on a swept-source optical coherence tomography (OCT) system. Shear waves were generated using a piezoelectric transducer transmitting sine-wave bursts of 400 μs duration, applying acoustic radiation force (ARF) to inhomogeneous phantoms and carotid artery samples, synchronized with a swept-source OCT (SS-OCT) imaging system. The phantoms were composed of gelatin and titanium dioxide whereas the carotid artery samples were embedded in gel. Differential OCT phase maps, measured with and without the ARF, detected the microscopic displacement generated by shear wave propagation in these phantoms and samples of different stiffness. We present the technique for calculating tissue mechanical properties by propagating shear waves in inhomogeneous tissue equivalent phantoms and carotid artery samples using the ARF of an ultrasound transducer, and measuring the shear wave speed and its associated properties in the different layers with OCT phase maps. This method lays the foundation for future in-vitro and in-vivo studies of mechanical property measurements of biological tissues such as vascular tissues, where normal and pathological structures may exhibit significant contrast in the shear modulus. PMID:24688822

  6. Phase estimation for global defocus correction in optical coherence tomography

    DEFF Research Database (Denmark)

    Jensen, Mikkel; Israelsen, Niels Møller; Podoleanu, Adrian

    2017-01-01

    In this work we investigate three techniques for estimation of the non-linear phase present due to defocus in opticalcoherence tomography, and apply them with the angular spectrum method. The techniques are: Least squarestting the of unwrapped phase of the angular spectrum, iterative optimization......, and sub-aperture correlations. The estimated phase of a single en-face image is used to extrapolate the non-linear phase at all depths, whichin the end can be used to correct the entire 3-D tomogram, and any other tomogram from the same system.......In this work we investigate three techniques for estimation of the non-linear phase present due to defocus in opticalcoherence tomography, and apply them with the angular spectrum method. The techniques are: Least squarestting the of unwrapped phase of the angular spectrum, iterative optimization...

  7. Computed tomography, nuclear medicine, ultrasound. Advanced diagnostic imaging for problematic areas in paediatric otolaryngology

    International Nuclear Information System (INIS)

    Noyek, A.M.; Friedberg, J.; Fitz, C.R.; Greyson, N.D.; Gilday, D.; Ash, J.; Miskin, M.; Rothberg, R.

    1982-01-01

    This presentation considers the diagnostic role of three major advanced imaging modalities in paediatric otolaryngology: computed tomography, nuclear medicine and ultrasound. These techniques allow for both more specific diagnosis, and for more precise understanding of the natural history of diagnoses already rendered. (Auth.)

  8. Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic.

    Science.gov (United States)

    Leo, Megan M; Langlois, Breanne K; Pare, Joseph R; Mitchell, Patricia; Linden, Judith; Nelson, Kerrie P; Amanti, Cristopher; Carmody, Kristin A

    2017-06-01

    Supporting an "ultrasound-first" approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis ( x 2 =51.7, pHydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR- 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03). Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

  9. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  10. An optimized ultrasound detector for photoacoustic breast tomography

    NARCIS (Netherlands)

    Xia, Wenfeng; Piras, Daniele; van Hespen, Johan C. G.; van Veldhoven, Spiridon; Prins, Christian; van Leeuwen, Ton G.; Steenbergen, Wiendelt; Manohar, Srirang

    2013-01-01

    Photoacoustic imaging has proven to be able to detect vascularization-driven optical absorption contrast associated with tumors. In order to detect breast tumors located a few centimeter deep in tissue, a sensitive ultrasound detector is of crucial importance for photoacoustic mammography. Further,

  11. NONINVASIVE DIAGNOSIS OF BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: A BLIND STATISTICAL STUDY

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available Whether cross-polarization (CP optical coherence tomography (OCT could be used to detect early bladder cancer was ascertained; it was compared with traditional OCT within the framework of blind (closed clinical statistical studies. One hundred and sixteen patients with local nonexophytic (flat pathological processes of the bladder were examined; 360 CP OCT images were obtained and analyzed. The study used an OCT 1300-U CP optical coherence tomographer. CP OCT showed a high (94% sensitivity and a high (84% specificity in the identification of suspected nonexophytic areas in the urinary bladder.

  12. Simultaneous measurement of group refractive index and thickness of optical samples using optical coherence tomography

    International Nuclear Information System (INIS)

    Cheng, Hsu-Chih; Liu, Yi-Cheng

    2010-01-01

    Optical coherence tomography (OCT), based on a Michelson interferometer and utilizing low coherence light as the optical source, is a novel technique for the noninvasive imaging of optical scattering media. A simple OCT scheme based on a 3x3 fiber coupler is presented for the simultaneous measurement of the refractive index and thickness of optical samples. The proposed system enables the refractive index and thickness to be determined without any prior knowledge of the sample parameters and is characterized by a simple and compact configuration, a straightforward measurement procedure, and a low cost. The feasibility of the proposed approach is demonstrated experimentally using BK7 and B270 optical glass samples.

  13. In vivo sweat film layer thickness measured with Fourier-domain optical coherence tomography

    CSIR Research Space (South Africa)

    Jonathan, E

    2008-01-01

    Full Text Available s Centre form the f th s pr t fi d id Keywords: Fourier-domain optical coherence tomography; Human sweat secretion; Sweat gland; Sweat duct; Hyperhidrosis growing list of triggers include cancer, glucose control disorder, mental stress, social..., that is, the gland, duct and pore(s). However, due to a slow imaging time, COCT is largely restricted to morphometry of human tissue and thickness measurement of biologic and biologic samples [12,13]. ARTICLE IN PRESS Fourier-domain optical coherence...

  14. Investigation of optical coherence tomography as an imaging modality in tissue engineering

    International Nuclear Information System (INIS)

    Yang Ying; Dubois, Arnaud; Qin Xiangpei; Li Jian; Haj, Alicia El; Wang, Ruikang K

    2006-01-01

    Monitoring cell profiles in 3D porous scaffolds presents a major challenge in tissue engineering. In this study, we investigate optical coherence tomography (OCT) as an imaging modality to monitor non-invasively both structures and cells in engineered tissue constructs. We employ time-domain OCT to visualize macro-structural morphology, and whole-field optical coherence microscopy to delineate the morphology of cells and constructs in a developing in vitro engineered bone tissue. The results show great potential for the use of OCT in non-invasive monitoring of cellular activities in 3D developing engineered tissues

  15. Simultaneous topography and tomography of latent fingerprints using full-field swept-source optical coherence tomography

    Science.gov (United States)

    Dubey, Satish Kumar; Singh Mehta, Dalip; Anand, Arun; Shakher, Chandra

    2008-01-01

    We demonstrate simultaneous topography and tomography of latent fingerprints using full-field swept-source optical coherence tomography (OCT). The swept-source OCT system comprises a superluminescent diode (SLD) as broad-band light source, an acousto-optic tunable filter (AOTF) as frequency tuning device, and a compact, nearly common-path interferometer. Both the amplitude and the phase map of the interference fringe signal are reconstructed. Optical sectioning of the latent fingerprint sample is obtained by selective Fourier filtering and the topography is retrieved from the phase map. Interferometry, selective filtering, low coherence and hence better resolution are some of the advantages of the proposed system over the conventional fingerprint detection techniques. The present technique is non-invasive in nature and does not require any physical or chemical processing. Therefore, the quality of the sample does not alter and hence the same fingerprint can be used for other types of forensic test. Exploitation of low-coherence interferometry for fingerprint detection itself provides an edge over other existing techniques as fingerprints can even be lifted from low-reflecting surfaces. The proposed system is very economical and compact.

  16. A bio-electromechanical imaging technique with combined electrical impedance and ultrasound tomography

    International Nuclear Information System (INIS)

    Steiner, G; Watzenig, D; Soleimani, M

    2008-01-01

    Electrical impedance tomography (EIT) seeks to image the electrical conductivity of an object using electrical impedance measurement data at its periphery. Ultrasound reflection tomography (URT) is an imaging modality that is able to generate images of mechanical properties of the object in terms of acoustic impedance changes. Both URT and EIT have the potential to be used in various medical applications. In this paper we focus on breast tumour detection. Both URT and EIT belong to soft field tomography and suffer from the small amounts of available data and the inherently ill-posed nature of the inverse problems. These facts result in limited achievable reconstruction accuracy and resolution. A dual bio-electromechanical tomography system using ultrasound and electrical tomography is proposed in this paper to improve the detection of the small-size tumour. Data fusion techniques are implemented to combine the EIT/URT data. Based on simulations, we demonstrate the improvement of detection of small size anomalies and improved depth detection compared to single modality soft field tomography

  17. Development of Fourier domain optical coherence tomography for applications in developmental biology

    Science.gov (United States)

    Davis, Anjul Maheshwari

    Developmental biology is a field in which explorations are made to answer how an organism transforms from a single cell to a complex system made up of trillions of highly organized and highly specified cells. This field, however, is not just for discovery, it is crucial for unlocking factors that lead to diseases, defects, or malformations. The one key ingredient that contributes to the success of studies in developmental biology is the technology that is available for use. Optical coherence tomography (OCT) is one such technology. OCT fills a niche between the high resolution of confocal microscopy and deep imaging penetration of ultrasound. Developmental studies of the chicken embryo heart are of great interest. Studies in mature hearts, zebrafish animal models, and to a more limited degree chicken embryos, indicate a relationship between blood flow and development. It is believed that at the earliest stages, when the heart is still a tube, the purpose of blood flow is not for convective transport of oxygen, nutrients and waster, bur rather to induce shear-related gene expressions to induce further development. Yet, to this date, the simple question of "what makes blood flow?" has not been answered. This is mainly due limited availability to adequate imaging and blood flow measurement tools. Earlier work has demonstrated the potential of OCT for use in studying chicken embryo heart development, however quantitative measurement techniques still needed to be developed. In this dissertation I present technological developments I have made towards building an OCT system to study chick embryo heart development. I will describe: (1) a swept-source OCT with extended imaging depth; (2) a spectral domain OCT system for non-invasive small animal imaging; (3) Doppler flow imaging and techniques for quantitative blood flow measurement in living chicken embryos; and (4) application of the OCT system that was developed in the Specific Aims 2-5 to test hypotheses generated by a

  18. Research of optical coherence tomography microscope based on CCD detector

    Science.gov (United States)

    Zhang, Hua; Xu, Zhongbao; Zhang, Shuomo

    2008-12-01

    The reference wave phase was modulated with a sinusoidal vibrating mirror attached to a Piezoelectric Transducer (PZT), the integration was performed by a CCD, and the charge storage period of the CCD image sensor was one-quarter period of the sinusoidal phase modulation. With the frequency- synchronous detection technique, four images (four frames of interference pattern) were recorded during one period of the phase modulation. In order to obtain the optimum modulation parameter, the values of amplitude and phase of the sinusoidal phase modulation were determined by considering the measurement error caused by the additive noise contained in the detected values. The PZT oscillation was controlled by a closed loop control system based on PID controller. An ideal discrete digital sine function at 50Hz with adjustable amplitude was used to adjust the vibrating of PZT, and a digital phase shift techniques was used to adjust vibrating phase of PZT so that the phase of the modulation could reach their optimum values. The CCD detector was triggered with software at 200Hz. Based on work above a small coherent signal masked by the preponderant incoherent background with a CCD detector was obtained.

  19. Transient spectral domain optical coherence tomography findings in classic MEWDS: a case report.

    Science.gov (United States)

    Lavigne, Luciana Castro; Isaac, David Leonardo Cruvinel; Duarte Júnior, José Osório; Avila, Marcos Pereira de

    2014-01-01

    The purpose of this study was to describe a patient with multiple evanescent white dot syndrome (MEWDS) who presented with classic retinal findings and transient changes in outer retinal anatomy. A 20-year-old man presented with mild blurred vision in the left eye, reporting flu-like symptoms 1 week before the visual symptoms started. Fundus examination of the left eye revealed foveal granularity and multiple scattered spots deep to the retina in the posterior pole. Fluorescein angiography and indocyanine green angiography showed typical MEWDS findings. Spectral Domain Optical Coherence Tomography has shown transient changes in outer retinal anatomy with disappearance of inner segment-outer segment junction and mild attenuation of external limiting membrane. Six months later, Spectral Domain Optical Coherence Tomography has shown complete resolution with recovery of normal outer retinal aspect.

  20. Early detection of tooth wear by en-face optical coherence tomography

    Science.gov (United States)

    Mărcăuteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Eniko; Hughes, Mike; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-02-01

    Excessive dental wear (pathological attrition and/or abfractions) is a frequent complication in bruxing patients. The parafunction causes heavy occlusal loads. The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-face optical coherence tomography was used for investigating and imaging of several extracted tooth, with a normal morphology, derived from patients with active bruxism and from subjects without parafunction. We found a characteristic pattern of enamel cracks in patients with first degree bruxism and with a normal tooth morphology. We conclude that the en-face optical coherence tomography is a promising non-invasive alternative technique for the early detection of occlusal overload, before it becomes clinically evident as tooth wear.

  1. A reconstruction algorithm for coherent scatter computed tomography based on filtered back-projection

    International Nuclear Information System (INIS)

    Stevendaal, U. van; Schlomka, J.-P.; Harding, A.; Grass, M.

    2003-01-01

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter form factor of the investigated object. Reconstruction from coherently scattered x-rays is commonly done using algebraic reconstruction techniques (ART). In this paper, we propose an alternative approach based on filtered back-projection. For the first time, a three-dimensional (3D) filtered back-projection technique using curved 3D back-projection lines is applied to two-dimensional coherent scatter projection data. The proposed algorithm is tested with simulated projection data as well as with projection data acquired with a demonstrator setup similar to a multi-line CT scanner geometry. While yielding comparable image quality as ART reconstruction, the modified 3D filtered back-projection algorithm is about two orders of magnitude faster. In contrast to iterative reconstruction schemes, it has the advantage that subfield-of-view reconstruction becomes feasible. This allows a selective reconstruction of the coherent-scatter form factor for a region of interest. The proposed modified 3D filtered back-projection algorithm is a powerful reconstruction technique to be implemented in a CSCT scanning system. This method gives coherent scatter CT the potential of becoming a competitive modality for medical imaging or nondestructive testing

  2. Fundamental characteristics of a synthesized light source for optical coherence tomography.

    Science.gov (United States)

    Sato, Manabu; Wakaki, Ichiro; Watanabe, Yuuki; Tanno, Naohiro

    2005-05-01

    We describe the fundamental characteristics of a synthesized light source (SLS) consisting of two low-coherence light sources to enhance the spatial resolution for optical coherence tomography (OCT). The axial resolution of OCT is given by half the coherence length of the light source. We fabricated a SLS with a coherence length of 2.3 microm and a side-lobe intensity of 45% with an intensity ratio of LED1:LED2 = 1:0.5 by combining two light sources, LED1, with a central wavelength of 691 nm and a spectral bandwidth of 99 nm, and LED2, with a central wavelength of 882 nm and a spectral bandwidth of 76 nm. The coherence length of 2.3 microm was 56% of the shorter coherence length in the two LEDs, which indicates that the axial resolution is 1.2 microm. The lateral resolution was measured at less than 4.4 microm by use of the phase-shift method and with a test pattern as a sample. The measured rough surfaces of a coin are illustrated and discussed.

  3. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array

    Energy Technology Data Exchange (ETDEWEB)

    O’Reilly, Meaghan A., E-mail: moreilly@sri.utoronto.ca; Jones, Ryan M. [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Birman, Gabriel [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Hynynen, Kullervo [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9 (Canada)

    2016-09-15

    Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  4. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array.

    Science.gov (United States)

    O'Reilly, Meaghan A; Jones, Ryan M; Birman, Gabriel; Hynynen, Kullervo

    2016-09-01

    Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  5. Ultrasound and computer tomography in the evaluation of focal liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, C; Ciatti, S; Lucarelli, E; Villari, N; de Dominicis, R [Florence Univ. (Italy). Ist. di Radiologia

    1981-01-01

    The results of ultrasound and computer tomography in 150 patients with possible focal liver disease were compared. Ultrasound was more sensitive than CT in detecting lesions but similar information on the nature of the lesion was obtained with both methods. CT provided more complete information than US on the extent of the lesion. Thus, CT and US are supplementary in the evaluation of focal liver disease. Because of the higher sensitivity US should be the first examination, followed, if clinically indicated, by CT for confirmation and possible further information regarding the extent of the lesion.

  6. Optical coherence tomography based microangiography: A tool good for dermatology applications (Conference Presentation)

    Science.gov (United States)

    Wang, Ruikang K.; Baran, Utku; Choi, Woo J.

    2016-02-01

    Optical coherence tomography (OCT) based microangiography (OMAG) is a new imaging technique enabling the visualization of blood flow within microcirculatory tissue beds in vivo with high resolution. In this talk, the concept and advantages of OMAG will be discussed and its potential clinical applications in the dermatology will be shown, demonstrating its usefulness in the clinical monitoring and therapeutic treatment of various skin pathologies, e.g. acne, port wine stain and wound healing.

  7. Pathogenesis of the dry eye syndrome observed by optical coherence tomography in vitro

    Science.gov (United States)

    Kray, Oya; Lenz, Markus; Spöler, Felix; Kray, Stefan; Kurz, Heinrich

    2011-06-01

    Three dimensional optical coherence tomography (OCT) is introduced as a valuable tool to analyze the pathogenesis of corneal diseases. Here, OCT in combination with a novel in vitro model for the dry eye syndrome enables an improved understanding of the underlying damaging process of the ocular surface. En-face OCT projections indicate a deep structural damage of the epithelium and anterior stroma by osmotic forces.

  8. Multiple-capillary measurement of RBC speed, flux, and density with optical coherence tomography.

    Science.gov (United States)

    Lee, Jonghwan; Wu, Weicheng; Lesage, Frederic; Boas, David A

    2013-11-01

    As capillaries exhibit heterogeneous and fluctuating dynamics even during baseline, a technique measuring red blood cell (RBC) speed and flux over many capillaries at the same time is needed. Here, we report that optical coherence tomography can capture individual RBC passage simultaneously over many capillaries located at different depths. Further, we demonstrate the ability to quantify RBC speed, flux, and linear density. This technique will provide a means to monitor microvascular flow dynamics over many capillaries at different depths at the same time.

  9. Blunt ocular trauma at the posterior pole in optical coherence tomography and fluorescein angiography

    International Nuclear Information System (INIS)

    Meyer, C.H.; Eter, N.; Mennel, S.; Kroll, P.

    2007-01-01

    Blunt ocular trauma at the posterior pole may involve a variety of retinal structures. We examined the most frequent retinal trauma (choroidal folds, commotion retinae, choroidal rupture, valsalva retinopathy, PPE-tears, Purtscher's Retinopathy etc.) by optical coherence tomography (OCT). The damaged pre-, intra- or subretinal structures were clearly visible. The OCT is during acute and chronic phases of different traumatic events an important diagnostic tool. (author) [de

  10. Spectral domain optical coherence tomography imaging of subretinal bands associated with chronic retinal detachments

    OpenAIRE

    Kothari, Nikisha; Kuriyan, Ajay E; Flynn, Harry W

    2016-01-01

    Nikisha Kothari, Ajay E Kuriyan, Harry W Flynn JrDepartment of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USAAbstract: We report three patients with subretinal bands associated with retinal detachment in chronic retinal detachments who underwent successful retinal reattachment. Subretinal bands before and after surgery can be identified on clinical examination and spectral domain optical coherence tomography. Removal of subr...

  11. Autofluorescence and high-definition optical coherence tomography of retinal artery occlusions

    OpenAIRE

    Mathew, Raeba; Papavasileiou, Evangelia; Sivaprasad, Sobha

    2010-01-01

    Raeba Mathew, Evangelia Papavasileiou, Sobha SivaprasadLaser and Retinal Research Unit, Department of Ophthalmology, King’s College Hospital, Denmark Hill, London, UKBackground: The purpose of this study is to illustrate the fundus autofluorescence and high-definition optical coherence tomography (HD-OCT) features of acute and long-standing retinal artery occlusions.Design: Retrospective case series.Participants: Patients with acute and chronic retinal and cilioretinal artery occlus...

  12. Fundus auto fluorescence and spectral domain ocular coherence tomography in the early detection of chloroquine retinopathy

    OpenAIRE

    Megan B. Goodman; Ari Ziskind

    2015-01-01

    Purpose: To determine the sensitivity of spectral domain ocular coherence tomography (SD-OCT) and fundus auto fluorescence (FAF) images as a screening test to detect early changes in the retina prior to the onset of chloroquine retinopathy. Method: The study was conducted using patients taking chloroquine (CQ), referred by the Rheumatology Department to the Ophthalmology Department at Tygerberg Academic Hospital. Group A consisted of 59 patients on CQ for less than 5 years, and Group B co...

  13. CHARACTERISTICS OF EPIRETINAL MEMBRANE REMNANT EDGE BY OPTICAL COHERENCE TOMOGRAPHY AFTER PARS PLANA VITRECTOMY.

    Science.gov (United States)

    Gaber, Raouf; You, Qi Sheng; Muftuoglu, Ilkay Kilic; Alam, Mostafa; Tsai, Frank F; Mendoza, Nadia; Freeman, William R

    2017-11-01

    To evaluate the incidence, characteristics, and the progression of epiretinal membrane (ERM) remnant edge seen by optical coherence tomography after ERM peeling. A retrospective chart review was conducted for 86 eyes of 85 consecutive patients who were diagnosed with ERM and underwent pars plana vitrectomy for epiretinal membrane peeling between 2013 and 2014. Data collected and analyzed included age, gender, preoperative and postoperative visual acuity, use of indocyanine green dye to stain internal limiting membrane, tamponade used after vitrectomy, ERM edge boundaries, presence of cystoid macular edema, and central foveal thickness. An ERM remnant edge was detected in 33/86 study eyes (38.4%) at the first postoperative optical coherence tomography scan. Compared with those without an ERM remnant, patients with an ERM remnant after surgery were significantly older at baseline and had a higher incidence of ERM recurrence at their last visit. They were not significantly different in terms of gender, preoperative and postoperative visual acuity, reduction of central foveal thickness from baseline, proportion of eyes with preoperative ERM elevation on optical coherence tomography, presence of macular edema before surgery, intraoperative use of indocyanine green staining for ILM peeling, or tamponade used. Based on the edge morphology, we classified the ERM remnant into three types: Type 1 was flat and blended with the retina (14/33 eyes, 42.4%), Type 2 was flat but stepped (17/33 eyes, 51.5%), and Type 3 was elevated (2/33 eyes, 6.0%). A significantly higher risk of ERM recurrence was seen in Type 2 and Type 3 ERM remnants (75% and 100%, respectively) than Type 1 ERM remnants (10%). An ERM remnant edge was detected by optical coherence tomography after ERM peeling in 38.4% of eyes. The presence of a postoperative ERM edge was associated with a higher risk of ERM recurrence, particularly in Type 2 and Type 3 ERM remnants.

  14. 3D handheld endoscope for optical coherence tomography of the human oral mucosa in vivo

    Science.gov (United States)

    Walther, Julia; Schnabel, Christian; Ebert, Nadja; Baumann, Michael; Koch, Edmund

    2017-07-01

    The early non-invasive diagnosis of epithelial tissue alterations in daily clinical routine is still challenging. Since optical coherence tomography (OCT) shows the potential to differentiate between benign and malignant tissue of primal endothelium, OCT could be beneficial for the early diagnosis of malignancies in routine health checks. In this research, a new handheld endoscopic scanning unit was designed and connected to a spectral domain OCT system of our workgroup for the in vivo imaging of the human oral mucosa.

  15. Spectral triangulation molecular contrast optical coherence tomography with indocyanine green as the contrast agent

    OpenAIRE

    Yang, Changhuei; McGuckin, Laura E. L.; Simon, John D.; Choma, Michael A.; Applegate, Brian E.; Izatt, Joseph A.

    2004-01-01

    We report a new molecular contrast optical coherence tomography (MCOCT) implementation that profiles the contrast agent distribution in a sample by measuring the agent's spectral differential absorption. The method, spectra triangulation MCOCT, can effectively suppress contributions from spectrally dependent scatterings from the sample without a priori knowledge of the scattering properties. We demonstrate molecular imaging with this new MCOCT modality by mapping the distribution of indocyani...

  16. [Deep learning and neuronal networks in ophthalmology : Applications in the field of optical coherence tomography].

    Science.gov (United States)

    Treder, M; Eter, N

    2018-04-19

    Deep learning is increasingly becoming the focus of various imaging methods in medicine. Due to the large number of different imaging modalities, ophthalmology is particularly suitable for this field of application. This article gives a general overview on the topic of deep learning and its current applications in the field of optical coherence tomography. For the benefit of the reader it focuses on the clinical rather than the technical aspects.

  17. Relationship between macular thickness measurement and signal strength using Stratus optical coherence tomography

    OpenAIRE

    Segal, Ori; Shapira, Yinon; Gershoni, Assaf; Vainer, Igor; Nemet, Arie Y; Geffen, Noa; Mimouni, Michael

    2016-01-01

    Ori Segal,1 Yinon Shapira,2 Assaf Gershoni,1 Igor Vainer,2 Arie Y Nemet,1 Noa Geffen,1 Michael Mimouni2 1Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel and the Sackler School of Medicine, Tel Aviv University, Tel Aviv, 2Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel Purpose: To examine the relationship between signal strength and macular thickness as measured by Stratus optical coherence tomography (OCT)’s fast macular thickness protocol...

  18. Four-dimensional Microscope-Integrated Optical Coherence Tomography to Visualize Suture Depth in Strabismus Surgery.

    Science.gov (United States)

    Pasricha, Neel D; Bhullar, Paramjit K; Shieh, Christine; Carrasco-Zevallos, Oscar M; Keller, Brenton; Izatt, Joseph A; Toth, Cynthia A; Freedman, Sharon F; Kuo, Anthony N

    2017-02-14

    The authors report the use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT), capable of live four-dimensional (three-dimensional across time) intraoperative imaging, to directly visualize suture depth during lateral rectus resection. Key surgical steps visualized in this report included needle depth during partial and full-thickness muscle passes along with scleral passes. [J Pediatr Ophthalmol Strabismus. 2017;54:e1-e5.]. Copyright 2017, SLACK Incorporated.

  19. Optical coherence tomography-current technology and applications in clinical and biomedical research

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Sander, Birgit; Mogensen, Mette

    2011-01-01

    Optical coherence tomography (OCT) is a noninvasive imaging technique that provides real-time two- and three-dimensional images of scattering samples with micrometer resolution. By mapping the local reflectivity, OCT visualizes the morphology of the sample. In addition, functional properties such...... biology. The number of companies involved in manufacturing OCT systems has increased substantially during the last few years (especially due to its success in opthalmology), and this technology can be expected to continue to spread into various fields of application....

  20. Ultrasound surveillance of endovascular aneurysm repair: a safe modality versus computed tomography.

    Science.gov (United States)

    Collins, John T; Boros, Michael J; Combs, Kristin

    2007-11-01

    Routine ultrasound surveillance is adequate and safe for monitoring endovascular aneurysm repairs (EVARs). A retrospective chart review including 160 endograft patients was performed from August 2000 to September 2005. All ultrasound examinations (n = 359) were performed by a board-certified vascular surgery group's accredited laboratory. Registered vascular technologists utilized the same equipment consisting of Siemens Antares high-definition ultrasonography with tissue harmonics and color flow Doppler. An identical protocol was followed by each technologist: scan body and both limbs of the endograft and distal iliac vessels, measure anterior-posterior aneurysm sac size, and detect intrasac pulsatility and color flow. Statistical analysis utilized Pearson's correlation coefficient and the paired t-test. Forty-one endoleaks were discovered out of the 359 exams (11.4%). There were type I (7, 17%), type II (26, 63%), and combined type I with type II (8, 20%) endoleaks. Correlation with computed tomography (CT) was obtained in 35 of these cases. CT discovered three endoleaks that were not seen with ultrasound. However, these particular ultrasound exams were inadequate due to additional factors (bowel gas, body habitus, hernia), which prompted CT investigation and, hence, endoleak discovery. Of the 41 endoleaks found on ultrasound, only 14 were seen on CT. Specifically, 26 type II endoleaks were seen with ultrasound versus only nine during CT. Additional factors addressed included comparison between ultrasound and CT of residual aneurysm sac measurements and conditions limiting ultrasound examination. Although criticized in the past, color flow ultrasonography is a safe and effective modality for surveillance of aortic endografts. Utilizing ultrasound to analyze abdominal aortic aneurysm (AAA) sac dimensions and endoleak detection is statistically sound for screening AAA status post-EVAR.

  1. EARLY SIMULTANEOUS FUNDUS AUTOFLUORESCENCE AND OPTICAL COHERENCE TOMOGRAPHY FEATURES AFTER PARS PLANA VITRECTOMY FOR PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT

    NARCIS (Netherlands)

    Dellʼomo, Roberto; Mura, Marco; Lesnik Oberstein, Sarit Y.; Bijl, Heico; Tan, H. Stevie

    2012-01-01

    Purpose: To describe fundus autofluorescence and optical coherence tomography (OCT) features of the macula after pars plana vitrectomy for rhegmatogenous retinal detachment. Methods: Thirty-three eyes of 33 consecutive patients with repaired rhegmatogenous retinal detachment with or without the

  2. In-situ biofouling assessment in spacer filled channels using optical coherence tomography (OCT): 3D biofilm thickness mapping

    KAUST Repository

    Fortunato, Luca; Leiknes, TorOve

    2017-01-01

    Membrane systems for water purification can be seriously hampered by biofouling. The use of optical coherence tomography (OCT) to investigate biofilms in membrane systems has recently increased due to the ability to do the characterization in

  3. Evaluation of the macular architecture of patients operated on from macula-off rhegmatogenous retinal detachment using optical coherence tomography

    International Nuclear Information System (INIS)

    Ramos Lopez, Meisy; Obret Mendive, Isabel; Hernandez Silva, Juan Raul

    2010-01-01

    With the support of optical coherence tomography, to evaluate the macular condition of the patients operated on from rhegmatogenous retinal detachment, with detached macula, who underwent buckling surgery and pars plana vitrectomy

  4. Ultrasound and computed tomography appearances of primary hepatic leiomyosarcoma

    International Nuclear Information System (INIS)

    Ghandhi, M.R.; Wong, D.C.; Wood, D.J.

    1995-01-01

    This paper describes the sonographic and computed tomography (CT) appearances of a primary leiomyosarcoma of the liver. The findings are non-specific and may be seen with a hepatocellular carcinoma. The role of imaging would seem to be in assessing the extent of the tumor, the degree of local vascular invasion and the presence of distant metastases. 10 refs; 4 figs

  5. Speckle-modulating optical coherence tomography in living mice and humans

    Science.gov (United States)

    Liba, Orly; Lew, Matthew D.; Sorelle, Elliott D.; Dutta, Rebecca; Sen, Debasish; Moshfeghi, Darius M.; Chu, Steven; de La Zerda, Adam

    2017-06-01

    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.

  6. An intelligent despeckling method for swept source optical coherence tomography images of skin

    Science.gov (United States)

    Adabi, Saba; Mohebbikarkhoran, Hamed; Mehregan, Darius; Conforto, Silvia; Nasiriavanaki, Mohammadreza

    2017-03-01

    Optical Coherence Optical coherence tomography is a powerful high-resolution imaging method with a broad biomedical application. Nonetheless, OCT images suffer from a multiplicative artefacts so-called speckle, a result of coherent imaging of system. Digital filters become ubiquitous means for speckle reduction. Addressing the fact that there still a room for despeckling in OCT, we proposed an intelligent speckle reduction framework based on OCT tissue morphological, textural and optical features that through a trained network selects the winner filter in which adaptively suppress the speckle noise while preserve structural information of OCT signal. These parameters are calculated for different steps of the procedure to be used in designed Artificial Neural Network decider that select the best denoising technique for each segment of the image. Results of training shows the dominant filter is BM3D from the last category.

  7. Simple and versatile long range swept source for optical coherence tomography applications

    International Nuclear Information System (INIS)

    Bräuer, Bastian; Lippok, Norman; Murdoch, Stuart G; Vanholsbeeck, Frédérique

    2015-01-01

    We present a versatile long coherence length swept-source laser design for optical coherence tomography applications. This design consists of a polygonal spinning mirror and an optical gain chip in a modified Littman–Metcalf cavity. A narrowband intra-cavity filter is implemented through multiple passes off a diffraction grating set at grazing incidence. The key advantage of this design is that it can be readily adapted to any wavelength regions for which broadband gain chips are available. We demonstrate this by implementing sources at 1650 nm, 1550 nm, 1310 nm and 1050 nm. In particular, we present a 1310 nm swept source laser with 24 mm coherence length, 95 nm optical bandwidth, 2 kHz maximum sweep frequency and 7.5 mW average output power. These parameters make it a suitable source for the imaging of biological samples. (paper)

  8. Benign familial fleck retina: multimodal imaging including optical coherence tomography angiography.

    Science.gov (United States)

    Garcia, Jose Mauricio Botto de Barros; Isaac, David Leonardo Cruvinel; Sardeiro, Tainara; Aquino, Érika; Avila, Marcos

    2017-01-01

    This report presents multimodal imaging of a 27-year-old woman diagnosed with benign familial fleck retina (OMIM 228980), an uncommon disorder. Fundus photographs revealed retinal flecks that affected her post-equatorial retina but spared the macular area. Fundus autofluorescence and infrared imaging demonstrated a symmetrical pattern of yellow-white fleck lesions that affected both eyes. Her full-field electroretinogram and electrooculogram were normal. An optical coherence tomography B-scan was performed for both eyes, revealing increased thickness of the retinal pigmented epithelium leading to multiple small pigmented epithelium detachments. The outer retina remained intact in both eyes. Spectral-domain optical coherence tomography angiography with split-spectrum amplitude decorrelation algorithm and 3 × 3 mm structural en face optical coherence tomography did not show macular lesions. Benign familial fleck retina belongs to a heterogenous group of so-called flecked retina syndromes, and should be considered in patients with yellowish-white retinal lesions without involvement of the macula.

  9. Benign familial fleck retina: multimodal imaging including optical coherence tomography angiography

    Directory of Open Access Journals (Sweden)

    Jose Mauricio Botto de Barros Garcia

    Full Text Available ABSTRACT This report presents multimodal imaging of a 27-year-old woman diagnosed with benign familial fleck retina (OMIM 228980, an uncommon disorder. Fundus photographs revealed retinal flecks that affected her post-equatorial retina but spared the macular area. Fundus autofluorescence and infrared imaging demonstrated a symmetrical pattern of yellow-white fleck lesions that affected both eyes. Her full-field electroretinogram and electrooculogram were normal. An optical coherence tomography B-scan was performed for both eyes, revealing increased thickness of the retinal pigmented epithelium leading to multiple small pigmented epithelium detachments. The outer retina remained intact in both eyes. Spectral-domain optical coherence tomography angiography with split-spectrum amplitude decorrelation algorithm and 3 × 3 mm structural en face optical coherence tomography did not show macular lesions. Benign familial fleck retina belongs to a heterogenous group of so-called flecked retina syndromes, and should be considered in patients with yellowish-white retinal lesions without involvement of the macula.

  10. Microscope Integrated Intraoperative Spectral Domain Optical Coherence Tomography for Cataract Surgery: Uses and Applications.

    Science.gov (United States)

    Das, Sudeep; Kummelil, Mathew Kurian; Kharbanda, Varun; Arora, Vishal; Nagappa, Somshekar; Shetty, Rohit; Shetty, Bhujang K

    2016-05-01

    To demonstrate the uses and applications of a microscope integrated intraoperative Optical Coherence Tomography in Micro Incision Cataract Surgery (MICS) and Femtosecond Laser Assisted Cataract Surgery (FLACS). Intraoperative real time imaging using the RESCAN™ 700 (Carl Zeiss Meditec, Oberkochen, Germany) was done for patients undergoing MICS as well as FLACS. The OCT videos were reviewed at each step of the procedure and the findings were noted and analyzed. Microscope Integrated Intraoperative Optical Coherence Tomography was found to be beneficial during all the critical steps of cataract surgery. We were able to qualitatively assess wound morphology in clear corneal incisions, in terms of subclinical Descemet's detachments, tears in the inner or outer wound lips, wound gaping at the end of surgery and in identifying the adequacy of stromal hydration, for both FLACS as well as MICS. It also enabled us to segregate true posterior polar cataracts from suspected cases intraoperatively. Deciding the adequate depth of trenching was made simpler with direct visualization. The final position of the intraocular lens in the capsular bag and the lack of bioadhesivity of hydrophobic acrylic lenses were also observed. Even though Microscope Integrated Intraoperative Optical Coherence Tomography is in its early stages for its application in cataract surgery, this initial assessment does show a very promising role for this technology in the future for cataract surgery both in intraoperative decision making as well as for training purposes.

  11. CAPILLARY NETWORK ALTERATIONS IN X-LINKED RETINOSCHISIS IMAGED ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

    Science.gov (United States)

    Romano, Francesco; Arrigo, Alessandro; Chʼng, Soon Wai; Battaglia Parodi, Maurizio; Manitto, Maria Pia; Martina, Elisabetta; Bandello, Francesco; Stanga, Paulo E

    2018-06-05

    To assess foveal and parafoveal vasculature at the superficial capillary plexus, deep capillary plexus, and choriocapillaris of patients with X-linked retinoschisis by means of optical coherence tomography angiography. Six patients with X-linked retinoschisis (12 eyes) and seven healthy controls (14 eyes) were recruited and underwent complete ophthalmologic examination, including best-corrected visual acuity, dilated fundoscopy, and 3 × 3-mm optical coherence tomography angiography macular scans (DRI OCT Triton; Topcon Corp). After segmentation and quality review, optical coherence tomography angiography slabs were imported into ImageJ 1.50 (NIH; Bethesda) and digitally binarized. Quantification of vessel density was performed after foveal avascular zone area measurement and exclusion. Patients were additionally divided into "responders" and "nonresponders" to dorzolamide therapy. Foveal avascular zone area resulted markedly enlarged at the deep capillary plexus (P < 0.001), particularly in nonresponders. Moreover, patients disclosed a significant deep capillary plexus rarefaction, when compared with controls (P: 0.04); however, a subanalysis revealed that this damage was limited to the fovea (P: 0.006). Finally, the enlargement of foveal avascular zone area positively correlated with a decline in best-corrected visual acuity (P: 0.01). Prominent foveal vascular impairment is detectable in the deep capillary plexus of patients with X-linked retinoschisis. Our results correlate with functional outcomes, suggesting a possible vascular role in X-linked retinoschisis clinical manifestations.

  12. Optical coherence tomography patterns as predictors of visual outcome in dengue-related maculopathy.

    Science.gov (United States)

    Teoh, Stephen C; Chee, Caroline K; Laude, Augustinus; Goh, Kong Y; Barkham, Timothy; Ang, Brenda S

    2010-03-01

    The purpose of this study was to characterize the presentations, long-term outcomes, and visual prognostic factors in dengue-related maculopathy of 41 patients with dengue fever and impaired vision from dengue-related maculopathy in a retrospective noninterventional and observational series. The medical records of patients with dengue-related maculopathy diagnosed over 18 months between July 2004 and December 2005 at The Eye Institute, Tan Tock Seng Hospital and Communicable Disease Center, Singapore, were reviewed and followed up for 24 months. Visual acuity and symptoms (presence of scotoma on automated visual fields and Amsler grid) were correlated with optical coherence tomography evaluation. Mean age was 28.7 years and there were more men (53.7%). The most common visual complaints were blurring of vision (51.2%) and central scotoma (34.1%). Most patients recovered best-corrected visual acuity >20/40. Optical coherence tomography showed 3 patterns of maculopathy: 1) diffuse retinal thickening; 2) cystoid macular edema; and 3) foveolitis. The visual outcome was independent of the extent of edema, but scotomata persisted longest in patients with foveolitis and shortest with those with diffuse retinal thickening. Dengue-associated ocular inflammation is an emerging ophthalmic condition and often involves the posterior segment. Prognosis is variable. Patients usually regain good vision but may retain persistent scotomata even at 2 years despite clinical resolution of the disease. Optical coherence tomography patterns in dengue maculopathy are useful for characterization, monitoring, and prognostication of the visual defect.

  13. Optical coherence tomography: a potential tool to predict premature rupture of fetal membranes.

    Science.gov (United States)

    Micili, Serap C; Valter, Markus; Oflaz, Hakan; Ozogul, Candan; Linder, Peter; Föckler, Nicole; Artmann, Gerhard M; Digel, Ilya; Artmann, Aysegul T

    2013-04-01

    A fundamental question addressed in this study was the feasibility of preterm birth prediction based on a noncontact investigation of fetal membranes in situ. Although the phenomena of preterm birth and the premature rupture of the fetal membrane are well known, currently, there are no diagnostic tools for their prediction. The aim of this study was to assess whether optical coherence tomography could be used for clinical investigations of high-risk pregnancies. The thickness of fetal membranes was measured in parallel by optical coherence tomography and histological techniques for the following types of birth: normal births, preterm births without premature ruptures and births at full term with premature rupture of membrane. Our study revealed that the membrane thickness correlates with the birth type. Normal births membranes were statistically significantly thicker than those belonging to the other two groups. Thus, in spite of almost equal duration of gestation of the normal births and the births at full term with premature rupture, the corresponding membrane thicknesses differed. This difference is possibly related to previously reported water accumulation in the membranes. The optical coherence tomography results were encouraging, suggesting that this technology could be used in future to predict and distinguish between different kinds of births.

  14. A case of unilateral circumscribed posterior keratoconus evaluated by three different imaging tools: optical coherence tomography, videokeratography, and Scheimpflug corneal tomography.

    Science.gov (United States)

    Spadea, Leopoldo; Maraone, Giorgia; Cagini, Carlo

    2017-02-01

    Posterior keratoconus is a rare corneal anomaly which is part of the ectatic corneal disorders. We report a clinical presentation of a unilateral posterior keratoconus in a 42-year-old man. At the time of presentation, corrected distance visual acuity (CDVA) was 20/20 with a correction of +2.50 +2.50 × 90° in the right eye and 20/40 with +1 +3.00 × 105° in the left eye. Slit lamp microscopy showed in the left eye an evidence of corneal thinning with a mild anterior protrusion and a remarkable posterior excavation. The intraocular pressure was 19 mmHg in right eye and 16 mmHg in left eye. Ultrasound pachymetry showed a minimum corneal thickness of 556 μ in right eye and 289 μ in left eye. The anterior segment optical coherence tomography (AS-OCT) revealed central corneal thinning and showed a reduced epithelial thickness. Videokeratography showed an increase of the corneal curvature in a defined area with central steepening in the area of the posterior corneal depression with gradual paracentral flattening. The description of this case underlines the importance of this instruments such us AS-OCT and corneal topography in diagnosis of posterior keratoconus. It can also be observed that in the contralateral eye there are no signs of ectasia as in the rare condition of unilateral keratoconus.

  15. Computed tomography (CT), nuclear medicine (NM), and ultrasound (US) in oncology patients

    International Nuclear Information System (INIS)

    McNeil, B.J.

    1982-01-01

    This review will summarize the effectiveness of computed tomography, ultrasound, and nuclear medicine imaging procedures in several different disease processes. The results indicate: (1) CT is clearly better than ultrasound for diseases of the adrenal gland and pancreas; (2) for patients with gynecologic malignancies, CT and ultrasound are approximately equivalent in their ability to define treatment options effectively; (3) in the liver, the differences among the three modalities are less marked and are disease specific. For example, for patients with colon cancer the increased effectiveness of CT relative to ultrasound or nuclear medicine is small. For patients with breast cancer, the difference is greater; (4) for patients suspected to have a focal source of sepsis, CT is slightly better than ultrasound or nuclear medicine. In these patients, however, when nuclear medicine images are obtained on a rectilinear scanner, the results are significantly worse compared to nuclear medicine images on a LFOV gamma camera or to ultrasound. As a result of the above studies and concommitant statistical analyses, several conclusions can be drawn about optimum experimental design and statistical approaches for comparing imaging modalities

  16. Preoperative diagnosis of Amyand's hernia by ultrasound and computed tomography

    Directory of Open Access Journals (Sweden)

    Husam Vehbi

    2016-06-01

    Full Text Available Inguinal hernia is the most common seen groin hernias which mostly contain bowel. The incidence of vermiform appendix in an inguinal hernia is seen in 1% of all inguinal hernia. This is known as Amyand's hernia. Appendix within a hernia can be normal or complicated by appendicitis. Most of these cases are not diagnosed preoperatively and managed during surgery. Preoperative diagnosis of these cases is so rare. Very few cases have been reported so far.In our case, we diagnosed an inflamed appendix in a 49 years old female within right inguinal hernia by using ultrasound and confirmed it by CT scan. Keywords: Amyand's hernia, Appendicitis

  17. X-ray coherent scattering tomography of textured material (Conference Presentation)

    Science.gov (United States)

    Zhu, Zheyuan; Pang, Shuo

    2017-05-01

    Small-angle X-ray scattering (SAXS) measures the signature of angular-dependent coherently scattered X-rays, which contains richer information in material composition and structure compared to conventional absorption-based computed tomography. SAXS image reconstruction method of a 2 or 3 dimensional object based on computed tomography, termed as coherent scattering computed tomography (CSCT), enables the detection of spatially-resolved, material-specific isotropic scattering signature inside an extended object, and provides improved contrast for medical diagnosis, security screening, and material characterization applications. However, traditional CSCT methods assumes materials are fine powders or amorphous, and possess isotropic scattering profiles, which is not generally true for all materials. Anisotropic scatters cannot be captured using conventional CSCT method and result in reconstruction errors. To obtain correct information from the sample, we designed new imaging strategy which incorporates extra degree of detector motion into X-ray scattering tomography for the detection of anisotropic scattered photons from a series of two-dimensional intensity measurements. Using a table-top, narrow-band X-ray source and a panel detector, we demonstrate the anisotropic scattering profile captured from an extended object and the reconstruction of a three-dimensional object. For materials possessing a well-organized crystalline structure with certain symmetry, the scatter texture is more predictable. We will also discuss the compressive schemes and implementation of data acquisition to improve the collection efficiency and accelerate the imaging process.

  18. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Directory of Open Access Journals (Sweden)

    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  19. Ultrasound compared with computed tomography and pancreatic arteriography in the detection of endocrine tumours of the pancreas

    International Nuclear Information System (INIS)

    Paeivaensalo, M.; Maekaeraeinen, H.; Siniluoto, T.; Staahlberg, M.; Jalovaara, P.; Oulu Univ. Central Hospital

    1989-01-01

    We have evaluated ultrasound, computed tomography and arteriographic findings in 15 patients with 17 endocrine pancreatic tumours having a mean diameter of 2.3 cm (range 1-7 cm). All patients underwent computed tomography, and all but one ultrasound and arteriography. Ultrasound was the initial investigation in 11 patients, and identified 10 of the 16 tumours present in 14 patients. Two tumours were found at ultrasound reexamination after having been identified by other radiological methods. Computed tomography revealed 8 out of 17 tumours, while arteriography identified 8 out of 16 tumours. Computed tomography was the initial investigation in 4 patients,and identified one tumour. In only 4 patients were tumours not detected by any of the imaging methods. The sensitivities of ultrasound, computed tomography and arteriography in the detection of pancreatic tumours were 62.5% (95% confidence interval 50.4-74.6%), 47.1% (95% confidence interval 35.0-59.2%), and 50.0% (95% confidence interval 37.5-62.5%), respectively. Ultrasound was thus more accurate than computed tomography or arteriography in detecting endocrine pancreatic tumours, and should be the initial radiological investigation. (orig.)

  20. Costs and role of ultrasound follow-up of polytrauma patients after initial computed tomography

    International Nuclear Information System (INIS)

    Maurer, M.H.; Winkler, A.; Powerski, M.J.; Elgeti, F.; Huppertz, A.; Roettgen, R.; Marnitz, T.; Wichlas, F.

    2012-01-01

    Purpose: To assess the costs and diagnostic gain of abdominal ultrasound follow-up of polytrauma patients initially examined by whole-body computed tomography (CT). Materials and Methods: A total of 176 patients with suspected multiple trauma (126 men, 50 women; age 43.5 ± 17.4 years) were retrospectively analyzed with regard to supplementary and new findings obtained by ultrasound follow-up compared with the results of exploratory FAST (focused assessment with sonography for trauma) at admission and the findings of whole-body CT. A process model was used to document the staff, materials, and total costs of the ultrasound follow-up examinations. Results: FAST yielded 26 abdominal findings (organ injury and/or free intra-abdominal fluid) in 19 patients, while the abdominal scan of whole-body CT revealed 32 findings in 25 patients. FAST had 81 % sensitivity and 100 % specificity. Follow-up ultrasound examinations revealed new findings in 2 of the 25 patients with abdominal injuries detected with initial CT. In the 151 patients without abdominal injuries in the initial CT scan, ultrasound follow-up did not yield any supplementary or new findings. The total costs of an ultrasound follow-up examination were EUR 28.93. The total costs of all follow-up ultrasound examinations performed in the study population were EUR 5658.23. Conclusion: Follow-up abdominal ultrasound yields only a low overall diagnostic gain in polytrauma patients in whom initial CT fails to detect any abdominal injuries but incurs high personnel expenses for radiological departments. (orig.)

  1. Imaging of dental material by polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Dichtl, Sabine; Baumgartner, Angela; Hitzenberger, Christoph K.; Moritz, Andreas; Wernisch, Johann; Robl, Barbara; Sattmann, Harald; Leitgeb, Rainer; Sperr, Wolfgang; Fercher, Adolf F.

    1999-05-01

    Partial coherence interferometry (PCI) and optical coherence tomography (OCT) are noninvasive and noncontact techniques for high precision biometry and for obtaining cross- sectional images of biologic structures. OCT was initially introduced to depict the transparent tissue of the eye. It is based on interferometry employing the partial coherence properties of a light source with high spatial coherence ut short coherence length to image structures with a resolution of the order of a few microns. Recently this technique has been modified for cross section al imaging of dental and periodontal tissues. In vitro and in vivo OCT images have been recorded, which distinguish enamel, cemento and dentin structures and provide detailed structural information on clinical abnormalities. In contrast to convention OCT, where the magnitude of backscattered light as a function of depth is imaged, polarization sensitive OCT uses backscattered light to image the magnitude of the birefringence in the sample as a function of depth. First polarization sensitive OCT recordings show, that changes in the mineralization status of enamel or dentin caused by caries or non-caries lesions can result in changes of the polarization state of the light backscattered by dental material. Therefore polarization sensitive OCT might provide a new diagnostic imaging modality in clinical and research dentistry.

  2. In vivo optical coherence tomography imaging of dissolution of hyaluronic acid microneedles in human skin (Conference Presentation)

    Science.gov (United States)

    Song, Seungri; Kim, Jung Dong; Bae, Jung-hyun; Chang, Sooho; Kim, Soocheol; Lee, Hyungsuk; Jeong, Dohyeon; Kim, Hong Kee; Joo, Chulmin

    2017-02-01

    Transdermal drug delivery (TDD) has been recently highlighted as an alternative to oral delivery and hypodermic injections. Among many methods, drug delivery using a microneedle (MN) is one of the promising administration strategies due to its high skin permeability, mininal invasiveness, and ease of injection. In addition, microneedle-based TDD is explored for cosmetic and therapeutic purposes, rapidly developing market of microneedle industry for general population. To date, visualization of microneedles inserted into biological tissue has primarily been performed ex vivo. MRI, CT and ultrasound imaging do not provide sufficient spatial resolution, and optical microscopy is not suitable because of their limited imaging depth; structure of microneedles located in 0.2 1mm into the skin cannot be visulalized. Optical coherence tomography (OCT) is a non-invasive, cross-sectional optical imaging modality for biological tissue with high spatial resolution and acquisition speed. Compared with ultrasound imaging, it exhibits superior spatial resolution (1 10 um) and high sensitivity, while providing an imaging depth of biological tissue down to 1 2 mm. Here, we present in situ imaging and analysis of the penetration and dissolution characteristics of hyaluronic acid based MNs (HA-MN) with various needle heights in human skin in vivo. In contrast to other studies, we measured the actual penetration depths of the HA-MNs by considering the experimentally measured refractive index of HA in the solid state. For the dissolution dynamics of the HA-MNs, time-lapse structural alteration of the MNs could be clearly visualized, and the volumetric changes of the MNs were measured with an image analysis algorithm.

  3. Ultrasound and computed tomography description of the liver the Boa constrictor

    International Nuclear Information System (INIS)

    Zulim, Rosalia Marina Infiesta; Geller, Felipe Foletto; Souza, Priscila Macedo de; Mamprim, Maria Jaqueline; Rossetti, Diogo Pascoal; Comerlato, Alexandra Tiso

    2012-01-01

    Ultrasound is a method for noninvasive diagnosis, their effectiveness in the diagnosis of liver disease has been described in snakes. The liver is the largest organ of the coelomic cavity of reptiles. Elongated and flattened. The caudal vena cava and portal vein divides the body into two lobes. The hepatic parenchyma is homogeneous hypoechoic echogenicity. The objective is to describe and to obtain reference images in the study of liver four snakes of Boa constrictor amarali, through an ultrasound and tomography. Physical restraint made for the ultrasound examination held in prone position, to compare the texture and mark the structures for the slices on CT. A linear multifrequency probe of 6-10 mHz was used. The anesthetic protocol for computed tomography consisted of isoflurane. In helical CT scanner, the animal was positioned in the prone position, and used continuous cross sections of 2 mm by 2. The ultrasound and CT examinations allowed the identification of liver contours as well as the definition and extension of the caudal vena cava and portal vein. Normal pattern recognition of CT aspect of the present study will be of help in the diagnosis of liver diseases in snakes (Boa constrictor amarali). (author)

  4. A Comparison of Endoscopic Ultrasound Guided Biopsy and Positron Emission Tomography with Integrated Computed Tomography in Lung Cancer Staging

    DEFF Research Database (Denmark)

    Larsen, Stine Schmidt; Vilmann, P; Krasnik, K

    2009-01-01

    BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...... had both procedures performed. PATIENTS AND METHODS: 27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour...

  5. Enhanced ultrasound for advanced diagnostics, ultrasound tomography for volume limb imaging and prosthetic fitting

    Science.gov (United States)

    Anthony, Brian W.

    2016-04-01

    Ultrasound imaging methods hold the potential to deliver low-cost, high-resolution, operator-independent and nonionizing imaging systems - such systems couple appropriate algorithms with imaging devices and techniques. The increasing demands on general practitioners motivate us to develop more usable and productive diagnostic imaging equipment. Ultrasound, specifically freehand ultrasound, is a low cost and safe medical imaging technique. It doesn't expose a patient to ionizing radiation. Its safety and versatility make it very well suited for the increasing demands on general practitioners, or for providing improved medical care in rural regions or the developing world. However it typically suffers from sonographer variability; we will discuss techniques to address user variability. We also discuss our work to combine cylindrical scanning systems with state of the art inversion algorithms to deliver ultrasound systems for imaging and quantifying limbs in 3-D in vivo. Such systems have the potential to track the progression of limb health at a low cost and without radiation exposure, as well as, improve prosthetic socket fitting. Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and quantitative process for prosthetic cup design and fabrication has not been fully demonstrated. Medical ultrasonography may inform the design process of prosthetic sockets in a more objective manner. This keynote talk presents the results of progress in this area.

  6. Three-dimensional reciprocal space x-ray coherent scattering tomography of two-dimensional object.

    Science.gov (United States)

    Zhu, Zheyuan; Pang, Shuo

    2018-04-01

    X-ray coherent scattering tomography is a powerful tool in discriminating biological tissues and bio-compatible materials. Conventional x-ray scattering tomography framework can only resolve isotropic scattering profile under the assumption that the material is amorphous or in powder form, which is not true especially for biological samples with orientation-dependent structure. Previous tomography schemes based on x-ray coherent scattering failed to preserve the scattering pattern from samples with preferred orientations, or required elaborated data acquisition scheme, which could limit its application in practical settings. Here, we demonstrate a simple imaging modality to preserve the anisotropic scattering signal in three-dimensional reciprocal (momentum transfer) space of a two-dimensional sample layer. By incorporating detector movement along the direction of x-ray beam, combined with a tomographic data acquisition scheme, we match the five dimensions of the measurements with the five dimensions (three in momentum transfer domain, and two in spatial domain) of the object. We employed a collimated pencil beam of a table-top copper-anode x-ray tube, along with a panel detector to investigate the feasibility of our method. We have demonstrated x-ray coherent scattering tomographic imaging at a spatial resolution ~2 mm and momentum transfer resolution 0.01 Å -1 for the rotation-invariant scattering direction. For any arbitrary, non-rotation-invariant direction, the same spatial and momentum transfer resolution can be achieved based on the spatial information from the rotation-invariant direction. The reconstructed scattering profile of each pixel from the experiment is consistent with the x-ray diffraction profile of each material. The three-dimensional scattering pattern recovered from the measurement reveals the partially ordered molecular structure of Teflon wrap in our sample. We extend the applicability of conventional x-ray coherent scattering tomography to

  7. Clinical utility of anterior segment swept-source optical coherence tomography in glaucoma

    Directory of Open Access Journals (Sweden)

    Dewang Angmo

    2016-01-01

    Full Text Available Optical coherence tomography (OCT, a noninvasive imaging modality that uses low-coherence light to obtain a high-resolution cross-section of biological structures, has evolved dramatically over the years. The Swept-source OCT (SS-OCT makes use of a single detector with a rapidly tunable laser as a light source. The Casia SS-1000 OCT is a Fourier-domain, SS-OCT designed specifically for imaging the anterior segment. This system achieves high resolution imaging of 10΅m (Axial and 30΅m (Transverse and high speed scanning of 30,000 A-scans per second. With a substantial improvement in scan speed, the anterior chamber angles can be imaged 360 degrees in 128 cross sections (each with 512 A-scans in about 2.4 seconds. We summarize the clinical applications of anterior segment SS-OCT in Glaucoma. Literature search: We searched PubMed and included Medline using the phrases anterior segment optical coherence tomography in ophthalmology, swept-source OCT, use of AS-OCT in glaucoma, use of swept-source AS-OCT in glaucoma, quantitative assessment of angle, filtering bleb in AS-OCT, comparison of AS-OCT with gonioscopy and comparison of AS-OCT with UBM. Search was made for articles dating 1990 to August 2015.

  8. Efficient scatter model for simulation of ultrasound images from computed tomography data

    Science.gov (United States)

    D'Amato, J. P.; Lo Vercio, L.; Rubi, P.; Fernandez Vera, E.; Barbuzza, R.; Del Fresno, M.; Larrabide, I.

    2015-12-01

    Background and motivation: Real-time ultrasound simulation refers to the process of computationally creating fully synthetic ultrasound images instantly. Due to the high value of specialized low cost training for healthcare professionals, there is a growing interest in the use of this technology and the development of high fidelity systems that simulate the acquisitions of echographic images. The objective is to create an efficient and reproducible simulator that can run either on notebooks or desktops using low cost devices. Materials and methods: We present an interactive ultrasound simulator based on CT data. This simulator is based on ray-casting and provides real-time interaction capabilities. The simulation of scattering that is coherent with the transducer position in real time is also introduced. Such noise is produced using a simplified model of multiplicative noise and convolution with point spread functions (PSF) tailored for this purpose. Results: The computational efficiency of scattering maps generation was revised with an improved performance. This allowed a more efficient simulation of coherent scattering in the synthetic echographic images while providing highly realistic result. We describe some quality and performance metrics to validate these results, where a performance of up to 55fps was achieved. Conclusion: The proposed technique for real-time scattering modeling provides realistic yet computationally efficient scatter distributions. The error between the original image and the simulated scattering image was compared for the proposed method and the state-of-the-art, showing negligible differences in its distribution.

  9. Noise study of all-normal dispersion supercontinuum sources for potential application in optical coherence tomography

    DEFF Research Database (Denmark)

    Bravo Gonzalo, Ivan; Engelsholm, Rasmus Dybbro; Bang, Ole

    2017-01-01

    bandwidths, such sources are characterized by large intensity fluctuations, limiting their performance for applications in imaging such as optical coherence tomography (OCT). An approach to eliminate the influence of noise sensitive effects is to use a so-called all-normal dispersion (ANDi) fiber, in which...... the dispersion is normal for all the wavelengths of interest. Pumping these types of fibers with short enough femtosecond pulses allows to suppress stimulated Raman scattering (SRS), which is known to be as noisy process as modulation instability (MI), and coherent SC is generated through self-phase modulation...... (SPM) and optical wave breaking (OWB). In this study, we show the importance of the pump laser and fiber parameters in the design of low-noise ANDi based SC sources, for application in OCT. We numerically investigate the pulse-to-pulse fluctuations of the SC, calculating the relative intensity noise...

  10. Dynamic focus optical coherence tomography: feasibility for improved basal cell carcinoma investigation

    Science.gov (United States)

    Nasiri-Avanaki, M. R.; Aber, Ahmed; Hojjatoleslami, S. A.; Sira, Mano; Schofield, John B.; Jones, Carole; Podoleanu, A. Gh.

    2012-03-01

    Basal cell carcinoma (BCC) is the most common form of skin cancer. To improve the diagnostic accuracy, additional non-invasive methods of making a preliminary diagnosis have been sought. We have implemented an En-Face optical coherence tomography (OCT) for this study in which the dynamic focus was integrated into it. With the dynamic focus scheme, the coherence gate moves synchronously with the peak of confocal gate determined by the confocal interface optics. The transversal resolution is then conserved throughout the depth range and an enhanced signal is returned from all depths. The Basal Cell Carcinoma specimens were obtained from the eyelid a patient. The specimens under went analysis by DF-OCT imaging. We searched for remarkable features that were visualized by OCT and compared these findings with features presented in the histology slices.

  11. NONINVASIVE DIAGNOSIS OF URINARY BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: CLINICAL RESULTS

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available The investigation examined the feasibility of cross-polarization optical cohe-rence tomography (CP OCT to detect early urinary bladder cancer (UBC. Studies were performed in 376 patients; 5290 images were obtained using an OCT 133-U optical coherence tomograph. To acquire and compare intrared-light scattering images in baseline and orthogonal polarizations is the basis of CP OCT; their analysis makes it possible to judge from the state of the epithelium/connective tissue system and to obtain information on changes in tissue depolarizing components, collagen in particular. The authors elaborated criteria as determinants of the nature of CP OCT changes in direct and orthogonal polarizations in health, inflammatory changes, and UBC at its early stage - urothelial dysplasia and carcinoma in situ in flat suspected areas.

  12. Theoretical and Experimental Study of Optical Coherence Tomography (OCT) Signals Using an Analytical Transport Model

    International Nuclear Information System (INIS)

    Vazquez Villa, A.; Delgado Atencio, J. A.; Vazquez y Montiel, S.; Cunill Rodriguez, M.; Martinez Rodriguez, A. E.; Ramos, J. Castro; Villanueva, A.

    2010-01-01

    Optical coherence tomography (OCT) is a non-invasive low coherent interferometric technique that provides cross-sectional images of turbid media. OCT is based on the classical Michelson interferometer where the mirror of the reference arm is oscillating and the signal arm contains a biological sample. In this work, we analyzed theoretically the heterodyne optical signal adopting the so called extended Huygens-Fresnel principle (EHFP). We use simulated OCT images with known optical properties to test an algorithm developed by ourselves to recover the scattering coefficient and we recovered the scattering coefficient with a relative error less than 5% for noisy signals. In addition, we applied this algorithm to OCT images from phantoms of known optical properties; in this case curves were indistinguishable. A revision of the validity of the analytical model applied to our system should be done.

  13. INFORMATIVITY OF SPECTRAL OPTICAL COHERENT TOMOGRAPHY IN AGGRESSIVE POSTERIOR RETINOPATHY OF PREMATURITY

    Directory of Open Access Journals (Sweden)

    A. V. Tereshchenko

    2017-01-01

    Full Text Available The purpose: to evaluate the informativity of optical coherence tomography in patients with aggressive posterior retinopathy of prematurity. Patients and methods. spectral optical coherence tomography using portable device iVue-100 with a removable camera (Optovue, USA was held in 32 children (64 eyes with aggressive posterior retinopathy of prematurity with a gestational period 26–31 week. Results. Children with aggressive posterior retinopathy of prematurity at the stage of early clinical manifestations, in addition to the indication that the immaturity of the retina, according to the spectral optical coherence tomography revealed only a few areas of epiretinal proliferation, which are not visualized with a digital retinoscopy and binocular indirect ophthalmoscopy. When the process is more pronounced in children with retinopathy of prematurity aggressive rear stage manifestation already determined multiple zones epiretinal proliferation as a "mushroom" and "flake" conglomerates with rear zone hyaloid membrane had an uneven seal. Coarser structural disorders of the retina and the vitreoretinal interface have been identified in patients with advancedstage aggressive posterior retinopathy of prematurity. We determined the shaft extraretinal proliferation as a "comb", as well as portions of epiretinal proliferation on the border of vascularized and avascular retina, which tended to merge, and the formation of massive hyperreflection complexes, lifted back hyaloid membrane, which was not only uneven sealed, but in some places is stratified. Conclusion. Despite the complexity of the procedure and the complexity of its implementation, the data obtained are particularly valuable and informative because they allow to complement the clinical picture and objectify it. It helps to choose the optimal tactics and improvement of a differentiated approach to the treatment of aggressive posterior retinopathy of prematurity.

  14. Imaging choroidal neovascular membrane using en face swept-source optical coherence tomography angiography

    Directory of Open Access Journals (Sweden)

    Moussa M

    2017-10-01

    Full Text Available Magdy Moussa,1,2 Mahmoud Leila,3 Hagar Khalid1,2 1Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Egypt; 2MEDIC Eye Center, Tanta, Egypt; 3Retina Department, Research Institute of Ophthalmology, Giza, Egypt Purpose: The aim of this study was to assess the efficacy of swept-source optical coherence tomography angiography (SS-OCTA in delineating the morphology of choroidal neovascular membrane (CNV. Patients and methods: This was a retrospective observational case series reviewing clinical data and fundus fluorescein angiography (FFA, swept-source optical coherence tomography (SS-OCT, and SS-OCTA images of patients with CNV and comparing the findings. The swept-source technology enables deeper penetration and superior axial resolution. The incorporated blood flow detection algorithm, optical coherence tomography angiography ratio analysis (OCTARA, enables visualization of CNV in vivo without the need for dye injection. Results: The study included 136 eyes of 105 patients. Active lesions on SS-OCTA images showed increased capillary density, extensive arborization, vascular anastomosis and looping, and peri-lesional hollow. Inactive lesions showed decreased capillary density, presence of large linear vessels, and presence of feeder vessels supplying the CNV. We detected positive correlation between SS-OCTA, FFA, and SS-OCT images in 97% of eyes. In the remaining 3%, SS-OCTA confirmed the absence of CNV, whereas FFA and SS-OCT either were inconclusive in the diagnosis of CNV or yielded false-positive results. Conclusion: SS-OCT and SS-OCTA represent a reproducible risk-free analog for FFA in imaging CNV. SS-OCTA is particularly versatile in cases where FFA and SS-OCT are inconclusive. Keywords: swept-source OCT, OCT angiography, imaging of CNV, OCTARA algorithm

  15. Optical coherence tomography findings and retinal changes after vitrectomy for optic disc pit maculopathy

    Directory of Open Access Journals (Sweden)

    Gaurav Sanghi

    2014-01-01

    Full Text Available Purpose : To study the optical coherence tomography (OCT patterns in optic disc pit maculopathy and retinal changes after vitreous surgery. Materials and Methods : Retrospective review of consecutive cases with optic disc pit maculopathy seen at two tertiary eye institutes from January 2005 to June 2009. Results : Twenty-four eyes of 23 patients are included. The presenting visual acuity ranged from 20/400 to 20/20 (median:20/80. The median age at presentation was 24 years (range, 6-57 years. Optical coherence tomography demonstrated a combination of retinoschisis and outer layer detachment (OLD in 19 (79.17% eyes, OLD only in 3 (12.5% eyes and retinoschisis only in 2 (8.33% eyes. An obvious communication (outer layer hole between the schisis and OLD was seen in 14 (73.68% of the 19 eyes with both features. Of the 21 eyes with retinoschisis, schisis was present in multiple layers in 15 (71.43% and single layer in 6 (28.57% eyes. Eleven eyes underwent pars plana vitrectomy including creation of posterior vitreous detachment (PVD, fluid-air exchange, low intensity laser photocoagulation at the temporal edge of the optic disc pit and non-expansile perfluoropropane gas (14% injection. Five (45.45% of 11 eyes undergoing vitrectomy had complete resolution and 4 (36.36% eyes had partial resolution of maculopathy. Visual acuity improved in 8 (72.72% of 11 eyes. Conclusion : Optical coherence tomography demonstrates multiple layer schisis and outer layer detachment as main features of optic disc pit maculopathy. Vitrectomy with PVD induction, laser photocoagulation and gas tamponade results in anatomical and visual improvement in most cases with optic disc pit maculopathy.

  16. Spectral domain optical coherence tomography imaging of spectacular ecdysis in the royal python (Python regius).

    Science.gov (United States)

    Tusler, Charlotte A; Maggs, David J; Kass, Philip H; Paul-Murphy, Joanne R; Schwab, Ivan R; Murphy, Christopher J

    2015-01-01

    To describe using spectral domain optical coherence tomography (SD-OCT), digital slit-lamp biomicroscopy, and external photography, changes in the ophidian cuticle, spectacle, and cornea during ecdysis. Four normal royal pythons (Python regius). Snakes were assessed once daily throughout a complete shed cycle using nasal, axial, and temporal SD-OCT images, digital slit-lamp biomicroscopy, and external photography. Spectral domain optical coherence tomography (SD-OCT) images reliably showed the spectacular cuticle and stroma, subcuticular space (SCS), cornea, anterior chamber, iris, and Schlemm's canal. When visible, the subspectacular space (SSS) was more distended peripherally than axially. Ocular surface changes throughout ecdysis were relatively conserved among snakes at all three regions imaged. From baseline (7 days following completion of a full cycle), the spectacle gradually thickened before separating into superficial cuticular and deep, hyper-reflective stromal components, thereby creating the SCS. During spectacular separation, the stroma regained original reflectivity, and multiple hyper-reflective foci (likely fragments from the cuticular-stromal interface) were noted within the SCS. The cornea was relatively unchanged in character or thickness throughout all stages of ecdysis. Slit-lamp images did not permit observation of these changes. Spectral domain optical coherence tomography (SD-OCT) provided excellent high-resolution images of the snake anterior segment, and especially the cuticle, spectacle, and cornea of manually restrained normal snakes at all stages of ecdysis and warrants investigation in snakes with anterior segment disease. The peripheral spectacle may be the preferred entry point for diagnostic or therapeutic injections into the SSS and for initiating spectacular surgery. © 2014 American College of Veterinary Ophthalmologists.

  17. Wavelet tree structure based speckle noise removal for optical coherence tomography

    Science.gov (United States)

    Yuan, Xin; Liu, Xuan; Liu, Yang

    2018-02-01

    We report a new speckle noise removal algorithm in optical coherence tomography (OCT). Though wavelet domain thresholding algorithms have demonstrated superior advantages in suppressing noise magnitude and preserving image sharpness in OCT, the wavelet tree structure has not been investigated in previous applications. In this work, we propose an adaptive wavelet thresholding algorithm via exploiting the tree structure in wavelet coefficients to remove the speckle noise in OCT images. The threshold for each wavelet band is adaptively selected following a special rule to retain the structure of the image across different wavelet layers. Our results demonstrate that the proposed algorithm outperforms conventional wavelet thresholding, with significant advantages in preserving image features.

  18. Morphological features in eyes with endophthalmitis after cataract surgery – histopathology and optical coherence tomography assessment

    DEFF Research Database (Denmark)

    Solborg Bjerrum, Søren; Prause, Jan Ulrik; Fuchs, Helle Josefine

    2016-01-01

    limiting membrane (ILM) of the retina (14 eyes versus 3 eyes, p = 0.015) and a higher degree of retinal atrophy temporal to the fovea (13 eyes versus 1 eye, p = 0.013) compared to fellow eyes. The histopathological analyses showed the formation of epiretinal membranes, derangement of all retinal layers...... with a reduced number of nuclei in the nuclear layers, loss of photoreceptor outer segments and massive retinal gliosis. CONCLUSIONS: Optical coherence tomography scans of the retina and histopathology analyses provide insights in the pathological process occurring in PE....

  19. High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography

    Science.gov (United States)

    Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.

    2010-09-07

    This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

  20. Subgingival calculus imaging based on swept-source optical coherence tomography

    Science.gov (United States)

    Hsieh, Yao-Sheng; Ho, Yi-Ching; Lee, Shyh-Yuan; Lu, Chih-Wei; Jiang, Cho-Pei; Chuang, Ching-Cheng; Wang, Chun-Yang; Sun, Chia-Wei

    2011-07-01

    We characterized and imaged dental calculus using swept-source optical coherence tomography (SS-OCT). The refractive indices of enamel, dentin, cementum, and calculus were measured as 1.625 +/- 0.024, 1.534 +/- 0.029, 1.570 +/- 0.021, and 2.097 +/- 0.094, respectively. Dental calculus leads strong scattering properties, and thus, the region can be identified from enamel with SS-OCT imaging. An extracted human tooth with calculus is covered with gingiva tissue as an in vitro sample for tomographic imaging.

  1. How histological features of basal cell carcinomas influence image quality in optical coherence tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Nürnberg, Birgit M.; Thrane, Lars

    2011-01-01

    Optical coherence tomography (OCT) has the potential to diagnose and measure the depth of nonmelanoma skin cancer (NMSC) in skin, but some lesions appear blurred in OCT images. The aim of this study is to identify histological characteristics of basal cell carcinomas (BCC) that correlate with good...... quality OCT images of the same lesions. A total of 34 patients with BCC were OCT scanned. The influence of histology parameters (e.g. inflammation, sun damage of skin, carcinoma cell size) on OCT image quality was studied by comparing 15 BCC lesions easily identified compared to 19 BCC lesions...

  2. Diagnostic value of optical coherence tomography for intracranial pressure in idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Skau, M; Yri, H; Sander, B

    2013-01-01

    BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition of raised intracranial pressure (ICP) in the absence of space-occupying lesions or other known etiology. It primarily affects young obese females, and potentially causes permanent visual loss due to papilledema and secondary...... optic atrophy. The aim of this study was to evaluate the diagnostic value of optical coherence tomography (OCT) as a marker for CSF opening pressure in patients with idiopathic intracranial hypertension (IIH). METHODS: We conducted a case-control study of 20 newly diagnosed, 21 long-term IIH patients...

  3. Correlation characteristics of optical coherence tomography images of turbid media with statistically inhomogeneous optical parameters

    International Nuclear Information System (INIS)

    Dolin, Lev S.; Sergeeva, Ekaterina A.; Turchin, Ilya V.

    2012-01-01

    Noisy structure of optical coherence tomography (OCT) images of turbid medium contains information about spatial variations of its optical parameters. We propose analytical model of statistical characteristics of OCT signal fluctuations from turbid medium with spatially inhomogeneous coefficients of absorption and backscattering. Analytically predicted correlation characteristics of OCT signal from spatially inhomogeneous medium are in good agreement with the results of correlation analysis of OCT images of different biological tissues. The proposed model can be efficiently applied for quantitative evaluation of statistical properties of absorption and backscattering fluctuations basing on correlation characteristics of OCT images.

  4. Optical coherence tomography following percutaneous coronary intervention with Excimer laser coronary atherectomy

    Energy Technology Data Exchange (ETDEWEB)

    Rawlins, John, E-mail: john.rawlins@doctors.net.uk; Talwar, Suneel; Green, Mark; O’Kane, Peter

    2014-01-15

    The indications for Excimer laser coronary atherectomy (ELCA) have been refined in modern interventional practice. With the expanding role for optical coherence tomography (OCT) providing high-resolution intra-coronary imaging, this article examines the appearance of the coronary lumen after ELCA. Each indication for ELCA is discussed and illustrated with a clinical case, followed by detailed analysis of the OCT imaging pre and post ELCA. The aim of the article is to provide information to interventional cardiologists to facilitate decision making during PCI, when ELCA has been used as part of the interventional strategy.

  5. Optical Coherence Tomography (OCT for Time-Resolved Imaging of Alveolar Dynamics in Mechanically Ventilated Rats

    Directory of Open Access Journals (Sweden)

    Christian Schnabel

    2017-03-01

    Full Text Available Though artificial ventilation is an essential life-saving treatment, the mechanical behavior of lung tissue at the alveolar level is still unknown. Therefore, we need to understand the tissue response during artificial ventilation at this microscale in order to develop new and more protective ventilation methods. Optical coherence tomography (OCT combined with intravital microscopy (IVM is a promising tool for visualizing lung tissue dynamics with a high spatial and temporal resolution in uninterruptedly ventilated rats. We present a measurement setup using a custom-made animal ventilator and a gating technique for data acquisition of time-resolved sequences.

  6. Extended depth of focus adaptive optics spectral domain optical coherence tomography

    Science.gov (United States)

    Sasaki, Kazuhiro; Kurokawa, Kazuhiro; Makita, Shuichi; Yasuno, Yoshiaki

    2012-01-01

    We present an adaptive optics spectral domain optical coherence tomography (AO-SDOCT) with a long focal range by active phase modulation of the pupil. A long focal range is achieved by introducing AO-controlled third-order spherical aberration (SA). The property of SA and its effects on focal range are investigated in detail using the Huygens-Fresnel principle, beam profile measurement and OCT imaging of a phantom. The results indicate that the focal range is extended by applying SA, and the direction of extension can be controlled by the sign of applied SA. Finally, we demonstrated in vivo human retinal imaging by altering the applied SA. PMID:23082278

  7. The early-stage diagnosis of albinic embryos by applying optical coherence tomography

    Science.gov (United States)

    Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

    2013-09-01

    Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

  8. Advances in clinical application of optical coherence tomography in vitreomacular interface disease

    Directory of Open Access Journals (Sweden)

    Xiao-Li Xing

    2013-08-01

    Full Text Available Vitreous macular interface disease mainly includes vitreomacular traction syndrome, idiopathic macular epiretinal membrane and idiopathic macular hole. Optical coherence tomography(OCTas a new tool that provides high resolution biopsy cross section image non traumatic imaging inspection, has a unique high resolution, no damage characteristics, and hence clinical widely used, vitreous macular interface for clinical disease diagnosis, differential diagnosis and condition monitoring and quantitative evaluation, treatment options, etc provides important information and reference value. Vitreous macular interface disease in OCT image of anatomical morphology characteristics, improve the clinical on disease occurrence and development of knowledge. We reviewed the advances in the application of OCT in vitreomacular interface disease.

  9. Optical coherence tomography imaging of cranial meninges post brain injury in vivo

    Institute of Scientific and Technical Information of China (English)

    Woo June Choi; Ruikang K.Wang

    2017-01-01

    We report a new application of optical coherence tomography (OCT) to investigate the cranial meninges in an animal model of brain injury in vivo.The injury is induced in a mouse due to skull thinning,in which the repeated and excessive drilling exerts mechanical stress on the mouse brain through the skull,resulting in acute and mild brain injury.Transcranial OCT imaging reveals an interesting virtual space between the cranial meningeal layers post skull thinning,which is gradually closed within hours.The finding suggests a promise of OCT as an effective tool to monitor the mechanical trauma in the small animal model of brain injury.

  10. Microfluidic volumetric flow determination using optical coherence tomography speckle: An autocorrelation approach

    Energy Technology Data Exchange (ETDEWEB)

    De Pretto, Lucas R., E-mail: lucas.de.pretto@usp.br; Nogueira, Gesse E. C.; Freitas, Anderson Z. [Instituto de Pesquisas Energéticas e Nucleares, IPEN–CNEN/SP, Avenida Lineu Prestes, 2242, 05508-000 São Paulo (Brazil)

    2016-04-28

    Functional modalities of Optical Coherence Tomography (OCT) based on speckle analysis are emerging in the literature. We propose a simple approach to the autocorrelation of OCT signal to enable volumetric flow rate differentiation, based on decorrelation time. Our results show that this technique could distinguish flows separated by 3 μl/min, limited by the acquisition speed of the system. We further perform a B-scan of gradient flow inside a microchannel, enabling the visualization of the drag effect on the walls.

  11. Spectral-domain optical coherence tomography staging and autofluorescence imaging in achromatopsia.

    Science.gov (United States)

    Greenberg, Jonathan P; Sherman, Jerome; Zweifel, Sandrine A; Chen, Royce W S; Duncker, Tobias; Kohl, Susanne; Baumann, Britta; Wissinger, Bernd; Yannuzzi, Lawrence A; Tsang, Stephen H

    2014-04-01

    IMPORTANCE Evidence is mounting that achromatopsia is a progressive retinal degeneration, and treatments for this condition are on the horizon. OBJECTIVES To categorize achromatopsia into clinically identifiable stages using spectral-domain optical coherence tomography and to describe fundus autofluorescence imaging in this condition. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was performed between 2010 and 2012 at the Edward S. Harkness Eye Institute, New York-Presbyterian Hospital. Participants included 17 patients (aged 10-62 years) with full-field electroretinography-confirmed achromatopsia. MAIN OUTCOMES AND MEASURES Spectral-domain optical coherence tomography features and staging system, fundus autofluorescence and near-infrared reflectance features and their correlation to optical coherence tomography, and genetic mutations served as the outcomes and measures. RESULTS Achromatopsia was categorized into 5 stages on spectral-domain optical coherence tomography: stage 1 (2 patients [12%]), intact outer retina; stage 2 (2 patients [12%]), inner segment ellipsoid line disruption; stage 3 (5 patients [29%]), presence of an optically empty space; stage 4 (5 patients [29%]), optically empty space with partial retinal pigment epithelium disruption; and stage 5 (3 patients [18%]), complete retinal pigment epithelium disruption and/or loss of the outer nuclear layer. Stage 1 patients showed isolated hyperreflectivity of the external limiting membrane in the fovea, and the external limiting membrane was hyperreflective above each optically empty space. On near infrared reflectance imaging, the fovea was normal, hyporeflective, or showed both hyporeflective and hyperreflective features. All patients demonstrated autofluorescence abnormalities in the fovea and/or parafovea: 9 participants (53%) had reduced or absent autofluorescence surrounded by increased autofluorescence, 4 individuals (24%) showed only reduced or absent autofluorescence, 3

  12. Assessment of wave propagation on surfaces of crystalline lens with phase sensitive optical coherence tomography

    International Nuclear Information System (INIS)

    Manapuram, R K; Larin, K V; Baranov, S A; Manne, V G R; Mashiatulla, M; Sudheendran, N; Aglyamov, S; Emelianov, S

    2011-01-01

    We propose a real-time technique based on phase-sensitive swept source optical coherence tomography (PhS-SSOCT) modality for noninvasive quantification of very small optical path length changes produced on the surface of a mouse crystalline lens. Propagation of submicron mechanical waves on the surface of the lens was induced by periodic mechanical stimulation. Obtained results demonstrate that the described method is capable of detecting minute damped vibrations with amplitudes as small as 30 nanometers on the lens surface and hence, PhS-SSOCT could be potentially used to assess biomechanical properties of a crystalline lens with high accuracy and sensitivity

  13. Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography

    Science.gov (United States)

    Herz, P. R.; Chen, Y.; Aguirre, A. D.; Schneider, K.; Hsiung, P.; Fujimoto, J. G.; Madden, K.; Schmitt, J.; Goodnow, J.; Petersen, C.

    2004-10-01

    A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

  14. Optical coherence tomography angiography: Technical principles and clinical applications in ophthalmology

    Directory of Open Access Journals (Sweden)

    Ahmed M Hagag

    2017-01-01

    Full Text Available Optical coherence tomography angiography (OCTA is a functional extension of OCT that provides information on retinal and choroidal circulations without the need for dye injections. With the recent development of high-speed OCT systems and efficient algorithms, OCTA has become clinically feasible. In this review article, we discuss the technical principles of OCTA, including image processing and artifacts, and its clinical applications in ophthalmology. We summarize recent studies which qualitatively or quantitatively assess disease presentation, progression, and/or response to treatment.

  15. Imaging of human breast tissue using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Verma, Y.; Gautam, M.; Divakar Rao, K.; Swami, M. K.; Gupta, P. K.

    2011-12-01

    We report a study on the use of polarization sensitive optical coherence tomography (PSOCT) for discriminating malignant (invasive ductal carcinoma), benign (fibroadenoma) and normal (adipocytes) breast tissue sites. The results show that while conventional OCT, that utilizes only the intensity of light back-scattered from tissue microstructures, is able to discriminate breast tissues as normal (adipocytes) and abnormal (malignant and benign) tissues, PS-OCT helps in discriminating between malignant and benign tissue sites also. The estimated values of birefringence obtained from the PSOCT imaging show that benign breast tissue samples have significantly higher birefringence as compared to the malignant tissue samples.

  16. Three-dimensional ophthalmic optical coherence tomography with a refraction correction algorithm

    Science.gov (United States)

    Zawadzki, Robert J.; Leisser, Christoph; Leitgeb, Rainer; Pircher, Michael; Fercher, Adolf F.

    2003-10-01

    We built an optical coherence tomography (OCT) system with a rapid scanning optical delay (RSOD) line, which allows probing full axial eye length. The system produces Three-dimensional (3D) data sets that are used to generate 3D tomograms of the model eye. The raw tomographic data were processed by an algorithm, which is based on Snell"s law to correct the interface positions. The Zernike polynomials representation of the interfaces allows quantitative wave aberration measurements. 3D images of our results are presented to illustrate the capabilities of the system and the algorithm performance. The system allows us to measure intra-ocular distances.

  17. In situ process monitoring in selective laser sintering using optical coherence tomography

    Science.gov (United States)

    Gardner, Michael R.; Lewis, Adam; Park, Jongwan; McElroy, Austin B.; Estrada, Arnold D.; Fish, Scott; Beaman, Joseph J.; Milner, Thomas E.

    2018-04-01

    Selective laser sintering (SLS) is an efficient process in additive manufacturing that enables rapid part production from computer-based designs. However, SLS is limited by its notable lack of in situ process monitoring when compared with other manufacturing processes. We report the incorporation of optical coherence tomography (OCT) into an SLS system in detail and demonstrate access to surface and subsurface features. Video frame rate cross-sectional imaging reveals areas of sintering uniformity and areas of excessive heat error with high temporal resolution. We propose a set of image processing techniques for SLS process monitoring with OCT and report the limitations and obstacles for further OCT integration with SLS systems.

  18. Full-field optical coherence tomography using immersion Mirau interference microscope.

    Science.gov (United States)

    Lu, Sheng-Hua; Chang, Chia-Jung; Kao, Ching-Fen

    2013-06-20

    In this study, an immersion Mirau interference microscope was developed for full-field optical coherence tomography (FFOCT). Both the reference and measuring arms of the Mirau interferometer were filled with water to prevent the problems associated with imaging a sample in air with conventional FFOCT systems. The almost-common path interferometer makes the tomographic system less sensitive to environmental disturbances. En face OCT images at various depths were obtained with phase-shifting interferometry and Hariharan algorithm. This immersion interferometric method improves depth and quality in three-dimensional OCT imaging of scattering tissue.

  19. Real-time Optical Coherence Tomography Incorporated in the Operating Microscope during Cataract Surgery.

    Science.gov (United States)

    Almutlak, Mohammed A; Aloniazan, Turki; May, William

    2017-01-01

    A 55-year-old male presented with reduced vision due to senile cataract. The patient consented to undergo real-time intraoperative anterior segment-optical coherence tomography (AS-OCT) during phacoemulsification with intraocular lens (IOL) implantation. Images were captured at various points during the surgery. The use of AS-OCT incorporated into the surgical microscope was evaluated as an adjunct to cataract surgery. We were able to successfully evaluate, in real-time, wound architecture, the attachment of Descemet's membrane, the posterior capsule, and IOL position. Real-time AS-OCT can be used to proactively address potential complications and verify IOL placement intraoperatively.

  20. Occlusal overload investigations by noninvasive technology: fluorescence microscopy and en-face optical coherence tomography

    Science.gov (United States)

    Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Enikö; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-07-01

    The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-Face Optical coherence tomography (eF-OCT) and fluorescence microscopy (FM) were used for the imaging of several anterior teeth extracted from patients with light active bruxism. We found a characteristic pattern of enamel cracks, that reached the tooth surface. We concluded that the combination of the en-Face OCT and FM is a promising non-invasive alternative technique for reliable monitoring of occlusal overload.

  1. Evaluation of Retinal Changes Using Optical Coherence Tomography in a Pediatric Case of Susac Syndrome

    Directory of Open Access Journals (Sweden)

    Mehmet Kola

    2017-01-01

    Full Text Available Susac syndrome is a rare occlusive vasculopathy affecting the retina, inner ear and brain. The cause is unknown, although it generally affects young women. This syndrome can be difficult to diagnose because its signs can only be revealed by detailed examination. These signs are not always concomitant, but may appear at different times. This report describes a pediatric case who was diagnosed with Susac syndrome when retinal lesions were identified in the inactive period with the help of optical coherence tomography (OCT. The purpose of this case report is to emphasize the importance of OCT in clarifying undefined retinal changes in Susac syndrome.

  2. In-vivo imaging of blood flow dynamics using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    2000-04-01

    Noninvasive quantitation of blood flow in the retinal micro circulation may elucidate the progression and treatment of ocular disorders including diabetic retinopathy, age-related degeneration, and glaucoma. Color Doppler optical coherence tomography was recently introduced as a technique allowing simultaneous micron-scale resolution cross-sectional imaging of tissue micro structure and blood flow in the human retina. Here, time-resolved imaging of dynamics of blood flow profiles was performed to measure cardiac pulsatility within retinal vessels. Retinal pulsatility has been shown to decrease throughout the progression of diabetic retinopathy.

  3. Fiber optic-based optical coherence tomography (OCT) for dental applications

    Science.gov (United States)

    Everett, Matthew J.; Colston, Bill W., Jr.; Da Silva, Luiz B.; Otis, Linda L.

    1998-09-01

    We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity. We have produced, using this scanning device, in vivo cross-sectional images of hard and soft dental tissues in human volunteers. Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento- enamel junction, were visible in all the images. The cemento- enamel junction and the alveolar bone were identified in approximately two thirds of the images. These images represent, or our knowledge, the first in vivo OCT images of human dental tissue.

  4. Simultaneous dual wavelength eye-tracked ultrahigh resolution retinal and choroidal optical coherence tomography

    DEFF Research Database (Denmark)

    Unterhuber, A.; Povaay, B.; Müller, André

    2013-01-01

    We demonstrate an optical coherence tomography device that simultaneously combines different novel ultrabroad bandwidth light sources centered in the 800 and 1060 nm regions, operating at 66 kHz depth scan rate, and a confocal laser scanning ophthalmoscope-based eye tracker to permit motion......-artifact-free, ultrahigh resolution and high contrast retinal and choroidal imaging. The two wavelengths of the device provide the complementary information needed for diagnosis of subtle retinal changes, while also increasing visibility of deeper-lying layers to image pathologies that include opaque media in the anterior...... eye segment or eyes with increased choroidal thickness....

  5. [Value of the optical coherence tomography in the treatment guided of the stent failure. Case report].

    Science.gov (United States)

    Macías, Enrico; Tellez, Alejandro; Ochoa, Jorge; Ortíz, José E

    2014-01-01

    Since the advent of bare metal and drug-eluting stents, the surgical revascularization have declined considerably, however the thrombosis and in-stent restenosis are important complications of these devices. There are several factors that predispose to thrombosis and in-stent restenosis. Conventional angiography has serious limitations to determine the causes of stent failure. Optical coherence tomography is a very sensitive technique to determine the cause of thrombosis and in-stent restenosis. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  6. Novel developments in Fourier domain optical coherence tomography and nonlinear tomographic interferometry

    OpenAIRE

    Mallat, Kamel

    2014-01-01

    In this thesis we present novel methods to improve the limitations in Optical Coherence Tomography (OCT). They are divided into two parts. The first part deals with the axial resolution limitation in OCT systems. We give a description of the Fourier Domain OCT (FDOCT), and then we show theoretically how to enhance the axial resolution in a particular case of a two-layer sample where one of the two layers is moving continuously, while these two layers are separated by a distance lower than the...

  7. Application of optical coherence tomography attenuation imaging for quantification of optical properties in medulloblastoma

    Science.gov (United States)

    Vuong, Barry; Skowron, Patryk; Kiehl, Tim-Rasmus; Kyan, Matthew; Garzia, Livia; Genis, Helen; Sun, Cuiru; Taylor, Michael D.; Yang, Victor X. D.

    2015-03-01

    The hemodynamic environment is known to play a crucial role in the progression, rupture, and treatment of intracranial aneurysms. Currently there is difficulty assessing and measuring blood flow profiles in vivo. An emerging high resolution imaging modality known as split spectrum Doppler optical coherence tomography (ssDOCT) has demonstrated the capability to quantify hemodynamic patterns as well as arterial microstructural changes. In this study, we present a novel in vitro method to acquire precise blood flow patterns within a patient- specific aneurysm silicone flow models using ssDOCT imaging. Computational fluid dynamics (CFD) models were generated to verify ssDOCT results.

  8. A computerized tomography system for transcranial ultrasound imaging.

    Science.gov (United States)

    Tang, Sai Chun; Clement, Gregory T

    Hardware for tomographic imaging presents both challenge and opportunity for simplification when compared with traditional pulse-echo imaging systems. Specifically, point diffraction tomography does not require simultaneous powering of elements, in theory allowing just a single transmit channel and a single receive channel to be coupled with a switching or multiplexing network. In our ongoing work on transcranial imaging, we have developed a 512-channel system designed to transmit and/or receive a high voltage signal from/to arbitrary elements of an imaging array. The overall design follows a hierarchy of modules including a software interface, microcontroller, pulse generator, pulse amplifier, high-voltage power converter, switching mother board, switching daughter board, receiver amplifier, analog-to-digital converter, peak detector, memory, and USB communication. Two pulse amplifiers are included, each capable of producing up to 400Vpp via power MOSFETS. Switching is based around mechanical relays that allow passage of 200V, while still achieving switching times of under 2ms, with an operating frequency ranging from below 100kHz to 10MHz. The system is demonstrated through ex vivo human skulls using 1MHz transducers. The overall system design is applicable to planned human studies in transcranial image acquisition, and may have additional tomographic applications for other materials necessitating a high signal output.

  9. Dual-Source Swept-Source Optical Coherence Tomography Reconstructed on Integrated Spectrum

    Directory of Open Access Journals (Sweden)

    Shoude Chang

    2012-01-01

    Full Text Available Dual-source swept-source optical coherence tomography (DS-SSOCT has two individual sources with different central wavelengths, linewidth, and bandwidths. Because of the difference between the two sources, the individually reconstructed tomograms from each source have different aspect ratio, which makes the comparison and integration difficult. We report a method to merge two sets of DS-SSOCT raw data in a common spectrum, on which both data have the same spectrum density and a correct separation. The reconstructed tomographic image can seamlessly integrate the two bands of OCT data together. The final image has higher axial resolution and richer spectroscopic information than any of the individually reconstructed tomography image.

  10. Spontaneous Coronary Dissection: “Live Flash” Optical Coherence Tomography Guided Angioplasty

    Science.gov (United States)

    Bento, Angela Pimenta; Fernandes, Renato Gil dos Santos Pinto; Neves, David Cintra Henriques Silva; Patrício, Lino Manuel Ribeiro; de Aguiar, José Eduardo Chambel

    2016-01-01

    Optical Coherence tomography (OCT) is a light-based imaging modality which shows tremendous potential in the setting of coronary imaging. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndrome (ACS). The diagnosis of SCAD is made mainly with invasive coronary angiography, although adjunctive imaging modalities such as computed tomography angiography, IVUS, and OCT may increase the diagnostic yield. The authors describe a clinical case of a young woman admitted with the diagnosis of ACS. The ACS was caused by SCAD detected in the coronary angiography and the angioplasty was guided by OCT. OCT use in the setting of SCAD has been already described and the true innovation in this case was this unique use of OCT. The guidance of angioplasty with live and short images was very useful as it allowed clearly identifying the position of the guidewires at any given moment without the use of prohibitive amounts of contrast. PMID:26989520

  11. Parental expectations, experiences and reactions, sense of coherence and grade of anxiety related to routine ultrasound examination with normal findings during pregnancy.

    Science.gov (United States)

    Ekelin, M; Crang Svalenius, E; Larsson, A-K; Nyberg, P; Marsál, K; Dykes, A-K

    2009-10-01

    To investigate parents' expectations, experiences and reactions, sense of coherence and anxiety before and after a second-trimester routine ultrasound examination, with normal findings. Before and after ultrasound questionnaires including the scales parents' expectations, experiences and reactions to routine ultrasound examination (PEER-U state of mind index), sense of coherence (SOC) and state and trait anxiety inventory (STAI), were sent to a 1-year cohort of women and their partners. Replies received were 2183. Both parents had significantly less worried state of mind (PEER-U) after the examination than before. Women had a lower grade of state anxiety after than before, but for men there was no significant change. Before the ultrasound, women had a higher degree of worried state of mind, as well as a higher grade of state and trait anxiety and a lower sense of coherence, than men. The women showed a greater reduction in worried state of mind than the men after the ultrasound examination. There were no significant differences in sense of coherence before and after ultrasound. Women and men are affected in their psychological well-being in relation to a routine ultrasound examination, but their sense of coherence remains stable.

  12. Visualisation of distribution of gold nanoparticles in liver tissues ex vivo and in vitro using the method of optical coherence tomography

    International Nuclear Information System (INIS)

    Genina, Elina A; Terentyuk, G S; Khlebtsov, B N; Bashkatov, A N; Tuchin, Valerii V

    2012-01-01

    The possibility of visualising the distribution of gold nanoparticles in liver by means of the method of optical coherence tomography is studied experimentally in model samples of beef liver in vitro and rat liver ex vivo. In the experiments we used the gold nanoparticles in the form of nanocages with resonance absorption in the near-IR spectral region. In the model studies the suspension of nanoparticles was applied to the surface of the sample, which then was treated with ultrasound. In the ex vivo studies the suspension of nanoparticles was injected to the laboratory rats intravenously. The image contrast and the optical depth of detection of blood vessels and liver structure components are calculated, as well as the depth of liver optical probing before and after the injection of nanoparticles. It was shown that the administration of the nanoparticle increases significantly the imaging contrast of liver blood vessels owing to the localisation of the nanoparticles therein.

  13. Visualisation of distribution of gold nanoparticles in liver tissues ex vivo and in vitro using the method of optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Genina, Elina A; Terentyuk, G S; Khlebtsov, B N; Bashkatov, A N; Tuchin, Valerii V

    2012-06-30

    The possibility of visualising the distribution of gold nanoparticles in liver by means of the method of optical coherence tomography is studied experimentally in model samples of beef liver in vitro and rat liver ex vivo. In the experiments we used the gold nanoparticles in the form of nanocages with resonance absorption in the near-IR spectral region. In the model studies the suspension of nanoparticles was applied to the surface of the sample, which then was treated with ultrasound. In the ex vivo studies the suspension of nanoparticles was injected to the laboratory rats intravenously. The image contrast and the optical depth of detection of blood vessels and liver structure components are calculated, as well as the depth of liver optical probing before and after the injection of nanoparticles. It was shown that the administration of the nanoparticle increases significantly the imaging contrast of liver blood vessels owing to the localisation of the nanoparticles therein.

  14. Multidetector row computed tomography and ultrasound characteristics of caudal vena cava duplication in dogs.

    Science.gov (United States)

    Bertolini, Giovanna; Diana, Alessia; Cipone, Mario; Drigo, Michele; Caldin, Marco

    2014-01-01

    Caudal vena cava duplication has been rarely reported in small animals. The purpose of this retrospective study was to describe characteristics of duplicated caudal vena cava in a large group of dogs. Computed tomography (CT) and ultrasound databases from two hospitals were searched for canine reports having the diagnosis "double caudal vena cava." One observer reviewed CT images for 71 dogs and two observers reviewed ultrasound images for 21 dogs. In all CT cases, the duplication comprised two vessels that were bilaterally symmetrical and approximately the same calibre (similar to Type I complete duplication in humans). In all ultrasound cases, the duplicated caudal vena cava appeared as a distinct vessel running on the left side of the abdominal segment of the descending aorta and extending from the left common iliac vein to the left renal vein. The prevalence of caudal vena cava duplication was 0.46% for canine ultrasound studies and 2.08% for canine CT studies performed at these hospitals. Median body weight for affected dogs was significantly lower than that of unaffected dogs (P dogs, caudal vena cava duplication should be differentiated from other vascular anomalies when planning surgeries and for avoiding misdiagnoses. © 2014 American College of Veterinary Radiology.

  15. Nondestructive observation of teeth post core-space using optical coherence tomography: comparison with microcomputed tomography and live images

    Science.gov (United States)

    Minamino, Takuya; Mine, Atsushi; Matsumoto, Mariko; Sugawa, Yoshihiko; Kabetani, Tomoshige; Higashi, Mami; Kawaguchi, Asuka; Ohmi, Masato; Awazu, Kunio; Yatani, Hirofumi

    2015-10-01

    No previous reports have observed inside the root canal using both optical coherence tomography (OCT) and x-ray microcomputed tomography (μCT) for the same sample. The purpose of this study was to clarify both OCT and μCT image properties from observations of the same root canal after resin core build-up treatment. As OCT allows real-time observation of samples, gap formation may be able to be shown in real time. A dual-cure, one-step, self-etch adhesive system bonding agent, and dual-cure resin composite core material were used in root canals in accordance with instructions from the manufacturer. The resulting OCT images were superior for identifying gap formation at the interface, while μCT images were better to grasp the tooth form. Continuous tomographic images from real-time OCT observation allowed successful construction of a video of the resin core build-up procedure. After 10 to 12 s of light curing, a gap with a clear new signal occurred at the root-core material interface, proceeding from the coronal side (6 mm from the cemento-enamel junction) to the apical side of the root.

  16. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography

    Science.gov (United States)

    Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2015-01-01

    Abstract. A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography (μCT) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In μCT, the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer–Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to 606  μm in SS-OCT. A correlation between μCT and SS-OCT was found regarding lesion depth (R=0.81, p<0.001) and also surface layer thickness (R=0.76, p<0.005). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution μCT without the use of x-ray. PMID:26158079

  17. Depth-resolved imaging of colon tumor using optical coherence tomography and fluorescence laminar optical tomography (Conference Presentation)

    Science.gov (United States)

    Tang, Qinggong; Frank, Aaron; Wang, Jianting; Chen, Chao-wei; Jin, Lily; Lin, Jon; Chan, Joanne M.; Chen, Yu

    2016-03-01

    Early detection of neoplastic changes remains a critical challenge in clinical cancer diagnosis and treatment. Many cancers arise from epithelial layers such as those of the gastrointestinal (GI) tract. Current standard endoscopic technology is unable to detect those subsurface lesions. Since cancer development is associated with both morphological and molecular alterations, imaging technologies that can quantitative image tissue's morphological and molecular biomarkers and assess the depth extent of a lesion in real time, without the need for tissue excision, would be a major advance in GI cancer diagnostics and therapy. In this research, we investigated the feasibility of multi-modal optical imaging including high-resolution optical coherence tomography (OCT) and depth-resolved high-sensitivity fluorescence laminar optical tomography (FLOT) for structural and molecular imaging. APC (adenomatous polyposis coli) mice model were imaged using OCT and FLOT and the correlated histopathological diagnosis was obtained. Quantitative structural (the scattering coefficient) and molecular imaging parameters (fluorescence intensity) from OCT and FLOT images were developed for multi-parametric analysis. This multi-modal imaging method has demonstrated the feasibility for more accurate diagnosis with 87.4% (87.3%) for sensitivity (specificity) which gives the most optimal diagnosis (the largest area under receiver operating characteristic (ROC) curve). This project results in a new non-invasive multi-modal imaging platform for improved GI cancer detection, which is expected to have a major impact on detection, diagnosis, and characterization of GI cancers, as well as a wide range of epithelial cancers.

  18. Time reversal and phase coherent music techniques for super-resolution ultrasound imaging

    Science.gov (United States)

    Huang, Lianjie; Labyed, Yassin

    2018-05-01

    Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements. A modified TR-MUSIC imaging algorithm is used to account for ultrasound scattering from both density and compressibility contrasts. The phase response of ultrasound transducer elements is accounted for in a PC-MUSIC system.

  19. Ultrasound appearance of radiation-induced hepatic injury. Correlation with computed tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Garra, B.S.; Shawker, T.H.; Chang, R.; Kaplan, K.; White, R.D.

    1988-01-01

    The ultrasound findings in three cases of radiation-induced hepatic injury are described and compared with computed tomography and magnetic resonance imaging findings. Fatty infiltration of the liver was present in two of the cases in which concurrent chemotherapy was being administered. On ultrasound B-scans, the regions of radiation injury were hypoechoic relative to the remainder of the liver. This finding was more obvious in the patients with fatty livers. CT scans on the patients with fatty infiltrated livers showed higher attenuation in the irradiated region than in unexposed liver. In the patient where no fatty infiltration was present, the radiated section of liver had lower attenuation consistent with previous reports. Magnetic resonance imaging showed decreased signal in the exposed areas on T1 weighted images

  20. Adenopathies in lung cancer: a comparison of pathology, Computed Tomography and endoscopic ultrasound findings

    International Nuclear Information System (INIS)

    Potepan, P.; Meroni, E.; Spinelli, P.

    1999-01-01

    A prospective comparative study with pathology was performed to assess the clinical value of Computed Tomography (CT) and endoscopic ultrasound (EUS) for nodal staging in lung cancer. A total of 329 nodal stations were dissected or sampled and 755 lymph nodes were examined at histology. On a pre-station basis, CT had greater sensitivity (74%) than EUS (56%), but EUS was more specific (83% versus 93%). The accuracy rates of the two techniques were similar. In conclusion, endoscopic ultrasound should be part of a routine preoperative diagnostic approach to non-small-cell lung cancer., because of its high specificity. Results can be improved when EUS and CT are combined., which suggests that these imaging modalities should be used together in selected patients for the noninvasive staging of non-small-cell lung cancer to identify local lymphatic spread [it

  1. [Chamber Angle Assessment in Clinical Practice - A Comparison between Optical Coherence Tomography and Gonioscopy].

    Science.gov (United States)

    Mösler, M P; Werner, J U; Lang, G K

    2015-07-01

    In glaucoma the structures of the anterior chamber are important for classification, therapy, progression and prognosis. In this context anterior segment optical coherence tomography (AS-OCT) gains more relevance. This study compares AS-OCT with gonioscopy in diagnostic performance of chamber angle (CA) assessment. 104 consecutive subjects with glaucoma underwent AS-OCT imaging using the Visante OCT. RESULTS were compared to gonioscopic grading from patient history using the Shaffer system. In addition, anterior chamber depth (ACD) assessment using slitlamp examination was evaluated as a prognostic factor for chamber angle width (CAW) and verified by AS-OCT measurement. Average CAW was 29° (AS-OCT). 17 % of the CAs that were "wide" in gonioscopy (variance 5-55°), showed a "narrow" CA in AS-OCT. 35 % of the CAs that were "narrow" in gonioscopy (variance 0-39°) showed a "wide" CA in AS-OCT. ACD assessment using slitlamp examination is a good predictor for CAW. In this context the technique provides equal informative value as gonioscopy. In cases of "wide" ACDs it is even superior. The critical ACD for an increased risk of angle closure is 2.4 mm. Concerning the critical ACD (gonioscopy difficult or impossible, optical coherence tomography is an effective alternative to the gold standard and is to some extent even superior. Georg Thieme Verlag KG Stuttgart · New York.

  2. Optical coherence tomography assessment and quantification of intracoronary thrombus: Status and perspectives

    International Nuclear Information System (INIS)

    Porto, Italo; Mattesini, Alessio; Valente, Serafina; Prati, Francesco; Crea, Filippo; Bolognese, Leonardo

    2015-01-01

    Coronary angiography is the “golden standard” imaging technique in interventional cardiology and it is still widely used to guide interventions. A major drawback of this technique, however, is that it is inaccurate in the evaluation and quantification of intracoronary thrombus burden, a critical prognosticator and predictor of intraprocedural complications in acute coronary syndromes. The introduction of optical coherence tomography (OCT) holds the promise of overcoming this important limitation, as near-infrared light is uniquely sensitive to hemoglobin, the pigment of red blood cells trapped in the thrombus. This narrative review will focus on the use of OCT for the assessment, evaluation and quantification of intracoronary thrombosis. - Highlights: • Thrombotic burden in acute coronary syndromes Is not adequately evaluated by standard coronary angiography, whereas Optical Coherence Tomography is exquisitely sensitive to the hemoglobin contained in red blood cells and can be used to precisely quantify thrombus. • Both research and clinical applications have been developed using the OCT-based evaluation of thrombus. In particular, whereas precise quantification scores are useful for comparing antithrombotic therapies in randomized trials, both pharmacological and mechanical, the most important practical applications for OCT-based assessment of thrombus are the individuation of culprit lesions in the context of diffuse atheromata in acute coronary syndromes, and the so-called “delayed stenting” strategies. • Improvements in 3D rendering techniques are on the verge of revolutionizing OCT-based thrombus assessment, allowing extremely precise quantification of the thrombotic burden

  3. Management of Patients with Graves’ Disease and Orbital Involvement: Role of Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Alice Bruscolini

    2018-01-01

    Full Text Available Purpose. To investigate the role of choroidal thickness evaluation with spectral domain optical coherence tomography (SDOCT and enhanced depth imaging (EDI technique in the management of patients with Graves’ disease and orbitopathy (GO. Methods. Thirty-six eyes of 18 patients with GO and 36 eyes of 18 age-matched control subjects were included in this retrospective observational study. All the subjects underwent a complete ophthalmological evaluation, including clinical activity score (CAS and exophthalmometry. The SDOCT images of the choroid were obtained by EDI modality. Results. Choroidal thickness was significantly increased in GO than in control eyes (p<0.01. A significant correlation was found between choroidal thickness and CAS, proptosis, and the duration of disease (p<0.05. Conclusion. This study shows that choroidal thickness, evaluated with EDI-OCT, is significantly increased in patients with GO and correlates with the activity of the disease, proptosis, and duration of the disease. The choroidal thickening may reflect the ocular hemodynamic changes, and enhanced depth imaging optical coherence tomography may be a useful tool for the evaluation of orbital congestion and management of patients with Graves’ disease and orbital involvement.

  4. Optical coherence tomography imaging of the basal ganglia: feasibility and brief review

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, W. O. Contreras; Ângelos, J. S. [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Martinez, R. C. R. [Laboratório de Neuromodulação e Dor Experimental, Hospital Sírio-Libanes, São Paulo, SP (Brazil); Takimura, C. K. [Instituto do Coração, Universidade de São Paulo, São Paulo, SP (Brazil); Teixeira, M. J. [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Lemos, P. A. Neto [Instituto do Coração, Universidade de São Paulo, São Paulo, SP (Brazil); Fonoff, E. T., E-mail: fonoffet@usp.br [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-09-29

    Optical coherence tomography (OCT) is a promising medical imaging technique that uses light to capture real-time cross-sectional images from biological tissues in micrometer resolution. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in cardiology and ophthalmology. Application of this technology in the brain may enable distinction between white matter and gray matter, and obtainment of detailed images from within the encephalon. We present, herein, the in vivo implementation of OCT imaging in the rat brain striatum. For this, two male 60-day-old rats (Rattus norvegicus, Albinus variation, Wistar) were stereotactically implanted with guide cannulas into the striatum to guide a 2.7-French diameter high-definition OCT imaging catheter (Dragonfly™, St. Jude Medical, USA). Obtained images were compared with corresponding histologically stained sections to collect imaging samples. A brief analysis of OCT technology and its current applications is also reported, as well as intra-cerebral OCT feasibility on brain mapping during neurosurgical procedures.

  5. Three-dimensional imaging of artificial fingerprint by optical coherence tomography

    Science.gov (United States)

    Larin, Kirill V.; Cheng, Yezeng

    2008-03-01

    Fingerprint recognition is one of the popular used methods of biometrics. However, due to the surface topography limitation, fingerprint recognition scanners are easily been spoofed, e.g. using artificial fingerprint dummies. Thus, biometric fingerprint identification devices need to be more accurate and secure to deal with different fraudulent methods including dummy fingerprints. Previously, we demonstrated that Optical Coherence Tomography (OCT) images revealed the presence of the artificial fingerprints (made from different household materials, such as cement and liquid silicone rubber) at all times, while the artificial fingerprints easily spoofed the commercial fingerprint reader. Also we demonstrated that an analysis of the autocorrelation of the OCT images could be used in automatic recognition systems. Here, we exploited the three-dimensional (3D) imaging of the artificial fingerprint by OCT to generate vivid 3D image for both the artificial fingerprint layer and the real fingerprint layer beneath. With the reconstructed 3D image, it could not only point out whether there exists an artificial material, which is intended to spoof the scanner, above the real finger, but also could provide the hacker's fingerprint. The results of these studies suggested that Optical Coherence Tomography could be a powerful real-time noninvasive method for accurate identification of artificial fingerprints real fingerprints as well.

  6. [Fluorescein angiography and optical coherence tomography findings in central fundus of myopic patients].

    Science.gov (United States)

    Avetisov, S E; Budzinskaya, M V; Zhabina, O A; Andreeva, I V; Plyukhova, A A; Kobzova, M V; Musaeva, G M

    2015-01-01

    Myopia prevalence grows alike in many countries, including Russia, regardless of geographical and population conditions. to assess fundus changes in myopic patients at different ocular axial lengths by means of modern diagnostic tools. The study enrolled 97 patients (194 eyes) aged 45 ± 20.17 years with myopia of different degrees. Besides a standard ophthalmic examination, all patients underwent fundus fluorescein angiography and optical coherence tomography. The occurrence of retinal pigment epithelium (RPE) atrophy (diffuse or focal) has been shown to increase with increasing ocular axial length. Only 27 eyes (28.1%) appeared intact. As myopia progression implies axial growth of the eye, it is associated with a more severe decrease in choroid, RPE, and photoreceptor layer thicknesses: the longer the anterior-posterior axis, the thinner the above mentioned fundus structures. Age-related changes in the fundus are also likely to be more pronounced in longer axes. Myopic traction maculopathy, which in our case appeared the main cause of increased retinal thickness, was diagnosed in 105 eyes, "outer" macular retinoschisis--in 40 eyes. Thus, modern diagnostic tools, such as fluorescein angiography and optical coherence tomography, enable objective assessment of the central fundus.

  7. REDUCED GANGLION CELL VOLUME ON OPTICAL COHERENCE TOMOGRAPHY IN PATIENTS WITH GEOGRAPHIC ATROPHY.

    Science.gov (United States)

    Ramkumar, Hema L; Nguyen, Brian; Bartsch, Dirk-Uwe; Saunders, Luke J; Muftuoglu, Ilkay Kilic; You, Qisheng; Freeman, William R

    2017-11-07

    Geographic atrophy (GA) is the sequelae of macular degeneration. Automated inner retinal analysis using optical coherence tomography is flawed because segmentation software is calibrated for normal eyes. The purpose of this study is to determine whether ganglion cell layer (GCL) volume is reduced in GA using manual analysis. Nineteen eyes with subfoveal GA and 22 controls were selected for morphometric analyses. Heidelberg scanning laser ophthalmoscope optical coherence tomography images of the optic nerve and macula were obtained, and the Viewing Module was used to manually calibrate retinal layer segmentation. Retinal layer volumes in the central 3-mm and surrounding 6-mm diameter were measured. Linear mixed models were used for statistics. The GCL volume in the central 3 mm of the macula is less (P = 0.003), and the retinal nerve fiber layer volume is more (P = 0.02) in patients with GA when compared with controls. Ganglion cell layer volume positively correlated with outer nuclear layer volume (P = 0.020). The patients with geographic atrophy have a small significant loss of the GCL. Ganglion cell death may precede axonal loss, and increased macular retinal nerve fiber layer volumes are not indicative of GCL volume. Residual ganglion cell stimulation by interneurons may enable vision in patients with GA.

  8. In situ gold nanoparticles formation: contrast agent for dental optical coherence tomography

    Science.gov (United States)

    Braz, Ana K. S.; Araujo, Renato E. de; Ohulchanskyy, Tymish Y.; Shukla, Shoba; Bergey, Earl J.; Gomes, Anderson S. L.; Prasad, Paras N.

    2012-06-01

    In this work we demonstrate the potential use of gold nanoparticles as contrast agents for the optical coherence tomography (OCT) imaging technique in dentistry. Here, a new in situ photothermal reduction procedure was developed, producing spherical gold nanoparticles inside dentinal layers and tubules. Gold ions were dispersed in the primer of commercially available dental bonding systems. After the application and permeation in dentin by the modified adhesive systems, the dental bonding materials were photopolymerized concurrently with the formation of gold nanoparticles. The gold nanoparticles were visualized by scanning electron microscopy (SEM). The SEM images show the presence of gold nanospheres in the hybrid layer and dentinal tubules. The diameter of the gold nanoparticles was determined to be in the range of 40 to 120 nm. Optical coherence tomography images were obtained in two- and three-dimensions. The distribution of nanoparticles was analyzed and the extended depth of nanosphere production was determined. The results show that the OCT technique, using in situ formed gold nanoparticles as contrast enhancers, can be used to visualize dentin structures in a non-invasive and non-destructive way.

  9. Comparison of Glaucoma Progression Detection by Optical Coherence Tomography and Visual Field.

    Science.gov (United States)

    Zhang, Xinbo; Dastiridou, Anna; Francis, Brian A; Tan, Ou; Varma, Rohit; Greenfield, David S; Schuman, Joel S; Huang, David

    2017-12-01

    To compare longitudinal glaucoma progression detection using optical coherence tomography (OCT) and visual field (VF). Validity assessment. We analyzed subjects with more than 4 semi-annual follow-up visits (every 6 months) in the multicenter Advanced Imaging for Glaucoma Study. Fourier-domain optical coherence tomography (OCT) was used to map the thickness of the peripapillary retinal nerve fiber layer (NFL) and ganglion cell complex (GCC). OCT-based progression detection was defined as a significant negative trend for either NFL or GCC. VF progression was reached if either the event or trend analysis reached significance. The analysis included 356 glaucoma suspect/preperimetric glaucoma (GS/PPG) eyes and 153 perimetric glaucoma (PG) eyes. Follow-up length was 54.1 ± 16.2 months for GS/PPG eyes and 56.7 ± 16.0 for PG eyes. Progression was detected in 62.1% of PG eyes and 59.8% of GS/PPG eyes by OCT, significantly (P glaucoma. While the utility of NFL declines in advanced glaucoma, GCC remains a sensitive progression detector from early to advanced stages. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Photoreceptor inner segment ellipsoid band integrity on spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Saxena S

    2014-12-01

    Full Text Available Sandeep Saxena,1 Khushboo Srivastav,1 Chui M Cheung,2 Joanne YW Ng,3 Timothy YY Lai3 1Retina Service, Department of Ophthalmology, King George’s Medical University Lucknow, India; 2Singapore National Eye Centre, Singapore; 3Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Kowloon, Hong Kong Abstract: Spectral domain optical coherence tomography cross-sectional imaging of the macula has conventionally been resolved into four bands. However, some doubts were raised regarding authentication of the existence of these bands. Recently, a number of studies have suggested that the second band appeared to originate from the inner segment ellipsoids of the foveal cone photoreceptors, and therefore the previously called inner segment-outer segment junction is now referred to as inner segment ellipsoidband. Photoreceptor dysfunction may be a significant predictor of visual acuity in a spectrum of surgical and medical retinal diseases. This review aims to provide an overview and summarizes the role of the photoreceptor inner segment ellipsoid band in the management and prognostication of various vitreoretinal diseases. Keywords: spectral domain optical coherence tomography, inner segment-outer segment junction, external limiting membrane, macular hole, diabetic macular edema, age relate macular degeneration

  11. Optical Coherence Tomography Angiography: Employing a Novel Technique for Investigation in Vogt-Koyanagi-Harada Disease.

    Science.gov (United States)

    Giannakouras, Panagiotis; Andreanos, Konstantinos; Giavi, Barbara; Diagourtas, Andreas

    2017-01-01

    To report a case of Vogt-Koyanagi-Harada (VKH) disease and describe the imaging findings by means of optical coherence tomography angiography (OCTA). Medical and ophthalmological history, ophthalmological examination, laboratory evaluation, B-scan ultrasonography, fluorescein and indocyanine angiography, and optical coherence tomography (OCT) were performed at baseline, as well as OCTA. A 50-year-old healthy female presented with decreased vision in both eyes. A Topcon DRI OCT Triton Plus swept source OCT system was used to visualize and evaluate the retinal and choroidal vascular plexus. Patchy and confluent dark areas in the superficial and deep retinal capillary plexus and choriocapillaris corresponded to areas of hypoperfusion, analyzed as areas of ischemia. VKH disease is characterized by ocular, neurological, and integumentary findings in its complete form. We present a case of incomplete disease in a 50-year-old female evaluated by means of OCTA which is a novel technique that provides depth-resolved images of the retina and choroidal microvasculature without dye injection that allows better visualization and detailed evaluation of the retinal and choroidal vascular plexus.

  12. Optical Coherence Tomography Angiography: Employing a Novel Technique for Investigation in Vogt-Koyanagi-Harada Disease

    Directory of Open Access Journals (Sweden)

    Panagiotis Giannakouras

    2017-07-01

    Full Text Available Purpose: To report a case of Vogt-Koyanagi-Harada (VKH disease and describe the imaging findings by means of optical coherence tomography angiography (OCTA. Methods: Medical and ophthalmological history, ophthalmological examination, laboratory evaluation, B-scan ultrasonography, fluorescein and indocyanine angiography, and optical coherence tomography (OCT were performed at baseline, as well as OCTA. Results: A 50-year-old healthy female presented with decreased vision in both eyes. A Topcon DRI OCT Triton Plus swept source OCT system was used to visualize and evaluate the retinal and choroidal vascular plexus. Patchy and confluent dark areas in the superficial and deep retinal capillary plexus and choriocapillaris corresponded to areas of hypoperfusion, analyzed as areas of ischemia. Conclusions and Importance: VKH disease is characterized by ocular, neurological, and integumentary findings in its complete form. We present a case of incomplete disease in a 50-year-old female evaluated by means of OCTA which is a novel technique that provides depth-resolved images of the retina and choroidal microvasculature without dye injection that allows better visualization and detailed evaluation of the retinal and choroidal vascular plexus.

  13. Collagen Content Limits Optical Coherence Tomography Image Depth in Porcine Vocal Fold Tissue.

    Science.gov (United States)

    Garcia, Jordan A; Benboujja, Fouzi; Beaudette, Kathy; Rogers, Derek; Maurer, Rie; Boudoux, Caroline; Hartnick, Christopher J

    2016-11-01

    Vocal fold scarring, a condition defined by increased collagen content, is challenging to treat without a method of noninvasively assessing vocal fold structure in vivo. The goal of this study was to observe the effects of vocal fold collagen content on optical coherence tomography imaging to develop a quantifiable marker of disease. Excised specimen study. Massachusetts Eye and Ear Infirmary. Porcine vocal folds were injected with collagenase to remove collagen from the lamina propria. Optical coherence tomography imaging was performed preinjection and at 0, 45, 90, and 180 minutes postinjection. Mean pixel intensity (or image brightness) was extracted from images of collagenase- and control-treated hemilarynges. Texture analysis of the lamina propria at each injection site was performed to extract image contrast. Two-factor repeated measure analysis of variance and t tests were used to determine statistical significance. Picrosirius red staining was performed to confirm collagenase activity. Mean pixel intensity was higher at injection sites of collagenase-treated vocal folds than control vocal folds (P Fold change in image contrast was significantly increased in collagenase-treated vocal folds than control vocal folds (P = .002). Picrosirius red staining in control specimens revealed collagen fibrils most prominent in the subepithelium and above the thyroarytenoid muscle. Specimens treated with collagenase exhibited a loss of these structures. Collagen removal from vocal fold tissue increases image brightness of underlying structures. This inverse relationship may be useful in treating vocal fold scarring in patients. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  14. Optical coherence tomography assessment and quantification of intracoronary thrombus: Status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Italo, E-mail: italo.porto@gmail.com [Interventional Cardiology Unit, San Donato Hospital, Arezzo (Italy); Mattesini, Alessio; Valente, Serafina [Interventional Cardiology Unit, Careggi Hospital, Florence (Italy); Prati, Francesco [Interventional Cardiology San Giovanni Hospital, Rome (Italy); CLI foundation (Italy); Crea, Filippo [Department of Cardiovascular Sciences, Catholic University of the Sacred Heart, Rome (Italy); Bolognese, Leonardo [Interventional Cardiology Unit, San Donato Hospital, Arezzo (Italy)

    2015-04-15

    Coronary angiography is the “golden standard” imaging technique in interventional cardiology and it is still widely used to guide interventions. A major drawback of this technique, however, is that it is inaccurate in the evaluation and quantification of intracoronary thrombus burden, a critical prognosticator and predictor of intraprocedural complications in acute coronary syndromes. The introduction of optical coherence tomography (OCT) holds the promise of overcoming this important limitation, as near-infrared light is uniquely sensitive to hemoglobin, the pigment of red blood cells trapped in the thrombus. This narrative review will focus on the use of OCT for the assessment, evaluation and quantification of intracoronary thrombosis. - Highlights: • Thrombotic burden in acute coronary syndromes Is not adequately evaluated by standard coronary angiography, whereas Optical Coherence Tomography is exquisitely sensitive to the hemoglobin contained in red blood cells and can be used to precisely quantify thrombus. • Both research and clinical applications have been developed using the OCT-based evaluation of thrombus. In particular, whereas precise quantification scores are useful for comparing antithrombotic therapies in randomized trials, both pharmacological and mechanical, the most important practical applications for OCT-based assessment of thrombus are the individuation of culprit lesions in the context of diffuse atheromata in acute coronary syndromes, and the so-called “delayed stenting” strategies. • Improvements in 3D rendering techniques are on the verge of revolutionizing OCT-based thrombus assessment, allowing extremely precise quantification of the thrombotic burden.

  15. Optical coherence tomography in diagnostics of precancer and cancer of human bladder

    Science.gov (United States)

    Zagaynova, Elena V.; Streltsova, Olga S.; Gladkova, Natalia D.; Shakhova, Natalia M.; Feldchtein, Felix I.; Kamensky, Vladislav A.; Gelikonov, Grigory V.; Snopova, Ludmila B.; Donchenko, Ekaterina V.

    2004-07-01

    Our goal was statistical assessment of the in vivo cystoscopic optical coherence tomography (OCT) ability to detect neoplasia in human urinary bladder. We analyzed major reasons of false positive and false negative image recognition results. Optical coherence tomography was performed to image the bladder during cystoscopy. The study enrolled 63 patients with suspicion for bladder cancer and scheduled for cystoscopy. The diagnosis was established by histopathology examination of a biopsy. Each biopsy site was examined by OCT. Benign conditions were diagnosed for 31 patients, and dysplasia or carcinoma were diagnosed for 32 patients. Six physicians blinded to all clinical data participated in the dichotomy recognition (malignant or benign) of the OCT images. 98% sensitivity and 72% specificity for the OCT recognition of dysplastic/malignant versus benign/reactive conditions of the bladder are demonstrated. Total error rate was 14.8%. The interobserver agreement multi-rater kappa coefficient is 0.80. The superficial and invasive bladder cancer and high-grade dysplasia were recognized with minimum error rate ranging from 0 to 3.3%. High sensitivity and good specificity of the OCT method in the diagnostics of bladder neoplasia makes OCT a promising complementary cystoscopic technique for non-invasive evaluation of zones suspicious for high-grade dysplasia and cancer.

  16. Endoscopic optical coherence tomography with a modified microelectromechanical systems mirror for detection of bladder cancers

    Science.gov (United States)

    Xie, Tuqiang; Xie, Huikai; Fedder, Gary K.; Pan, Yingtian

    2003-11-01

    Experimental results of a modified micromachined microelectromechanical systems (MEMS) mirror for substantial enhancement of the transverse laser scanning performance of endoscopic optical coherence tomography (EOCT) are presented. Image distortion due to buckling of MEMS mirror in our previous designs was analyzed and found to be attributed to excessive internal stress of the transverse bimorph meshes. The modified MEMS mirror completely eliminates bimorph stress and the resultant buckling effect, which increases the wobbling-free angular optical actuation to greater than 37°, exceeding the transverse laser scanning requirements for EOCT and confocal endoscopy. The new optical coherence tomography (OCT) endoscope allows for two-dimensional cross-sectional imaging that covers an area of 4.2 mm × 2.8 mm (limited by scope size) and at roughly 5 frames/s instead of the previous area size of 2.9 mm × 2.8 mm and is highly suitable for noninvasive and high-resolution imaging diagnosis of epithelial lesions in vivo. EOCT images of normal rat bladders and rat bladder cancers are compared with the same cross sections acquired with conventional bench-top OCT. The results clearly demonstrate the potential of EOCT for in vivo imaging diagnosis and precise guidance for excisional biopsy of early bladder cancers.

  17. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

    Science.gov (United States)

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-07-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

  18. New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images

    International Nuclear Information System (INIS)

    Duan, Jinming; Bai, Li; Tench, Christopher; Gottlob, Irene; Proudlock, Frank

    2015-01-01

    Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation. (paper)

  19. SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY REVEALS INTERNAL LIMITING MEMBRANE PEELING ALTERS DEEP RETINAL VASCULATURE.

    Science.gov (United States)

    Michalewska, Zofia; Nawrocki, Jerzy

    2018-04-30

    To describe morphology of retinal and choroidal vessels in swept-source optical coherence tomography angiography before and after vitrectomy with the temporal inverted internal limiting membrane (ILM) flap technique for full-thickness macular holes. Prospective, observational study of 36 eyes of 33 patients with full-thickness macular holes swept-source optical coherence tomography angiography was performed in patients before and 1 month after vitrectomy. Vitrectomy with the temporal inverted ILM flap technique was performed. In this method, ILM is peeled only at one side of the fovea. An ILM flap is created to cover the macular hole. Comparison of retina vasculature in the areas of ILM peeling vs. no ILM peeling at 1 and 3 months after successful vitrectomy was performed. The study demonstrated lower density of vessels in the deep retinal plexus in the area where ILM was peeled as compared to the rest of the fovea. Visual acuity and central retinal thickness 1 month after surgery correlates with fovea avascular zone diameter in deep retinal layers at the same time point (P = 0.001). This study confirmed that ILM peeling might alter blood flow in deep retinal vessels below the peeling area in the early postoperative period. The area of the fovea avascular zone corresponds to functional results at the same time point.

  20. Deep convolutional neural networks for estimating porous material parameters with ultrasound tomography

    Science.gov (United States)

    Lähivaara, Timo; Kärkkäinen, Leo; Huttunen, Janne M. J.; Hesthaven, Jan S.

    2018-02-01

    We study the feasibility of data based machine learning applied to ultrasound tomography to estimate water-saturated porous material parameters. In this work, the data to train the neural networks is simulated by solving wave propagation in coupled poroviscoelastic-viscoelastic-acoustic media. As the forward model, we consider a high-order discontinuous Galerkin method while deep convolutional neural networks are used to solve the parameter estimation problem. In the numerical experiment, we estimate the material porosity and tortuosity while the remaining parameters which are of less interest are successfully marginalized in the neural networks-based inversion. Computational examples confirms the feasibility and accuracy of this approach.

  1. Contrast-enhanced ultrasound vs multidetector-computed tomography for detecting liver metastases in colorectal cancer: a prospective, blinded, patient-by-patient analysis

    DEFF Research Database (Denmark)

    Rafaelsen, S R; Jakobsen, A

    2011-01-01

    This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer.......This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer....

  2. Examination of diagnostic features in multiphoton microscopy and optical coherence tomography images of ovarian tumorigenesis in a mouse model

    Science.gov (United States)

    Watson, Jennifer M.

    Ovarian cancer is a deadly disease owing to the non-specific symptoms and suspected rapid progression, leading to frequent late stage detection and poor prognosis. Medical imaging methods such as CT, MRI and ultrasound as well as serum testing for cancer markers have had extremely poor performance for early disease detection. Due to the poor performance of available screening methods, and the impracticality and ineffectiveness of taking tissue biopsies from the ovary, women at high risk for developing ovarian cancer are often advised to undergo prophylactic salpingo-oophorectomy. This surgery results in many side effects and is most often unnecessary since only a fraction of high risk women go on to develop ovarian cancer. Better understanding of the early development of ovarian cancer and characterization of morphological changes associated with early disease could lead to the development of an effective screening test for women at high risk. Optical imaging methods including optical coherence tomography (OCT) and multiphoton microscopy (MPM) are excellent tools for studying disease progression owing to the high resolution and depth sectioning capabilities. Further, these techniques are excellent for optical biopsy because they can image in situ non-destructively. In the studies described in this dissertation OCT and MPM are used to identify cellular and tissue morphological changes associated with early tumor development in a mouse model of ovarian cancer. This work is organized into three specific aims. The first aim is to use the images from the MPM phenomenon of second harmonic generation to quantitatively examine the morphological differences in collagen structure in normal mouse ovarian tissue and mouse ovarian tumors. The second aim is to examine the differences in endogenous two-photon excited fluorescence in normal mouse ovarian tissue and mouse ovarian tumors. The third and final aim is to identify changes in ovarian microstructure resulting from early

  3. Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Staging of Patients with Non-Small Cell Lung Cancer without Mediastinal Involvement at Positron Emission Tomography-Computed Tomography

    DEFF Research Database (Denmark)

    Naur, Therese Maria Henriette; Konge, Lars; Clementsen, Paul Frost

    2017-01-01

    BACKGROUND: Staging of lung cancer is essential to the treatment, which is curative only in cases of localized disease. Previous studies have suggested that endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is unnecessary when positron emission tomography-computed tomog...

  4. Retinal layer measurements after successful macula-off retinal detachment repair using optical coherence tomography.

    Science.gov (United States)

    Menke, Marcel N; Kowal, Jens H; Dufour, Pascal; Wolf-Schnurrbusch, Ute E; Ceklic, Lala; Framme, Carsten; Wolf, Sebastian

    2014-09-04

    Optical coherence tomography (OCT) was used to analyze the thickness of various retinal layers of patients following successful macula-off retinal detachment (RD) repair. Optical coherence tomography scans of patients after successful macula-off RD repair were reanalyzed with a subsegmentation algorithm to measure various retinal layers. Regression analysis was performed to correlate time after surgery with changes in layer thickness. In addition, patients were divided in two groups. Group 1 had a follow-up period after surgery of up to 7 weeks (range, 21-49 days). In group 2, the follow-up period was >8 weeks (range, 60-438 days). Findings were compared to a group of age-matched healthy controls. Correlation analysis showed a significant positive correlation between inner nuclear-outer plexiform layer (INL-OPL) thickness and time after surgery (P=0.0212; r2=0.1551). Similar results were found for the ellipsoid zone-retinal pigment epithelium complex (EZ-RPE) thickness (P=0.005; r2=0.2215). Ganglion cell-inner plexiform layer thickness (GCL-IPL) was negatively correlated with time after surgery (P=0.0064; r2=0.2101). For group comparison, the retinal nerve fiber layer in both groups was thicker compared to controls. The GCL-IPL showed significant thinning in group 2. The outer nuclear layer was significantly thinner in groups 1 and 2 compared to controls. The EZ-RPE complex was significantly thinner in groups 1 and 2 compared to controls. In addition, values in group 1 were significantly thinner than in group 2. Optical coherence tomography retinal layer thickness measurements after successful macular-off RD repair revealed time-dependent thickness changes. Inner nuclear-outer plexiform layer thickness and EZ-RPE thickness was positively correlated with time after surgery. Ganglion cell-inner plexiform layer thickness was negatively correlated with time after surgery. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  5. EVALUATION OF DIABETIC MACULAR OEDEMA WITH SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY AND FUNDUS FLUORESCEIN ANGIOGRAPHY

    Directory of Open Access Journals (Sweden)

    Mallika Venkitasubramanian

    2017-02-01

    Full Text Available BACKGROUND Macular oedema is an important cause of visual morbidity in Diabetic Retinopathy. It can be assessed by both Fundus Fluorescein Angiography (FFA and Optical Coherence Tomography (OCT. The aims of this study were to evaluate the agreement between morphological features on spectral domain Optical Coherence Tomography and Fluorescein Angiographic leakage patterns in Diabetic Macular Oedema, and to study the correlation between the best corrected visual acuity and central foveal thickness measured by Optical Coherence Tomography. MATERIALS AND METHODS This was an observational study. All patients with Diabetic Macular Oedema underwent complete ophthalmic examination and subjected to FFA and OCT. Presence or absence of macular oedema by FFA and OCT was noted and agreement between two modalities of imaging was assessed. Sensitivity of these modalities were also found out using appropriate statistical methods. Best Corrected Visual Acuity (BCVA measured were converted to LogMAR scale and Central foveal thickness measured by OCT. Linear regression analysis was done with central foveal thickness and LogMAR visual acuity. RESULTS A total of 69 eyes of 39 patients were studied. OCT revealed Diabetic Macular Oedema in 97.5% of eyes. Fundus Fluorescein Angiography performed in these patients identified leakage in 95.6% of eyes. Sensitivity and specificity of FFA and OCT were calculated keeping one as the gold standard for sensitivity and specificity of the other. FFA and OCT had almost equal sensitivity (95.46 for OCT and 96.92 for FFA for detection of DME. Specificity of OCT was found to be slightly higher (33.33% compared to FFA (25%. Our results suggest that there is minimal agreement between these two imaging modalities in evaluating DME. Statistically, Kappa value was 0.248. Linear regression analysis showed that central foveal thickness had a significant correlation with visual acuity, with Pearson correlation coefficient r=0.442, p=0

  6. Optical Coherence Tomography Parameters in Morbidly Obese Patients Who Underwent Laparoscopic Sleeve Gastrectomy

    Directory of Open Access Journals (Sweden)

    Berna Dogan

    2016-01-01

    Full Text Available Purpose. To investigate changes in optical coherence tomography parameters in morbidly obese patients who had undergone laparoscopic sleeve gastrectomy (LSG. Methods. A total of 41 eyes of 41 morbidly obese patients (BMI ≥ 40 who had undergone LSG were included in study. The topographic optic disc parameters, central macular thickness (CMT, total macular volume (TMV, and retinal ganglion cell layer (RGCL were measured by spectral-domain optical coherence tomography (SD-OCT. Subfoveal choroidal thickness (SFCT was measured by enhanced deep imaging-optical coherence tomography (EDI-OCT. Results. The mean CMT was 237.4±24.5 μm, 239.3±24.1 μm, and 240.4±24.5 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean TMV was 9.88±0.52 mm3, 9.96±0.56 mm3, and 9.99±0.56 mm3 preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean RGCL was 81.2±6.5 μm, 82.7±6.6 μm, and 82.9±6.5 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean SFCT was 309.8±71.8 μm, 331.0±81.4 μm, and 352.7±81.4 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. No statistically significant differences were found between the preoperative values and 3- and 6-month postoperative values in rim area (p=0.34, disc area (p=0.64, vertical cup/disc ratio (p=0.39, cup volume (p=0.08, or retinal nerve fiber layer (p=0.90. Conclusions. Morbidly obese patients who undergo LSG experience a statistically significant increase in CMT, TMV, SFCT, and RGCL at 3 months and 6 months after surgery.

  7. SUPER-RESOLUTION ULTRASOUND TOMOGRAPHY: A PRELIMINARY STUDY WITH A RING ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    HUANG, LIANJIE [Los Alamos National Laboratory; SIMONETTI, FRANCESCO [NON LANL; DURIC, NEBOJSA [NON LANL; RAMA, OLSI [NON LANL

    2007-01-18

    Ultrasound tomography attempts to retrieve the structure of an objective by exploiting the interaction of acoustic waves with the object. A fundamental limit of ultrasound tomography is that features cannot be resolved if they are spaced less than {lambda}/2 apart, where {lambda} is wavelength of the probing wave, regardless of the degree of accuracy of the measurements. Therefore, since the attenuation of the probing wave with propagation distance increases as {lambda} decreases, resolution has to be traded against imaging depth. Recently, it has been shown that the {lambda}/2 limit is a consequence of the Born approximation (implicit in the imaging algorithms currently employed) which neglects the distortion of the probing wavefield as it travels through the medium to be imaged. On the other hand, such a distortion, which is due to the multiple scattering phenomenon, can encode unlimited resolution in the radiating component of the scattered field. Previously, a resolution better than {lambda}/3 has been reported in these proceedings [F. Simonetti, pp. 126 (2006)] in the case of elastic wave probing. In this paper, they demonstrate experimentally a resolution better than {lambda}/4 for objects immersed in a water bth probed by means of a ring array which excites and detects pressure waves in a full view configuration.

  8. Repeatability of pachymetric mapping using fourier domain optical coherence tomography in corneas with opacities.

    Science.gov (United States)

    Samy El Gendy, Nehal M; Li, Yan; Zhang, Xinbo; Huang, David

    2012-04-01

    To evaluate the repeatability of Fourier domain optical coherence tomography (OCT) pachymetric mapping in patients with corneal opacities and to assess the reliability of Fourier domain OCT with 830 nm wavelength as a pachymetric measurement tool in opaque corneas. A Fourier domain OCT system was used to map the corneal thickness of patients with corneal scars or dystrophy. A retrospective study of a consecutive series was conducted. The repeatability was measured using pooled standard deviation of repeated measurements. A slit-scanning tomography device provided pachymetric mapping for comparison. Seventeen eyes of 12 patients with corneal scars (7 trauma and 3 post infection) or dystrophy (2 Reis-Bucklers and 5 granular dystrophy) were included. The posterior corneal boundary was detectable in all cases. The average corneal thickness measured by OCT was 536 ± 89 μm in central 2 mm area, 553 ± 76 μm in pericentral 2- to 5-mm area, and 508 ± 93 μm for the minimum corneal thickness. The slit-scanning tomography central corneal thickness, 433 ± 111 μm, was significantly lower than OCT readings (mean difference -91.1 ± 33.3 μm, P = 0.002). Repeatability of the OCT measurements was 2.1 μm centrally and 1.2 μm pericentrally. Pachymetric mapping with Fourier domain OCT was highly repeatable. Fourier domain OCT is a reliable pachymetric tool in opaque corneas. In comparison, corneal thickness measured by the slit-scanning tomography is significantly thinner than those measured by the Fourier domain OCT in the presence of corneal opacities.

  9. Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

    Science.gov (United States)

    Fang, You-Qiang; Wu, Jie-Ying; Li, Teng-Cheng; Zheng, Hao-Feng; Liang, Guan-Can; Chen, Yan-Xiong; Hong, Xiao-Bin; Cai, Wei-Zhong; Zang, Zhi-Jun; Di, Jin-Ming

    2017-06-01

    This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ± 4.3 minutes) was shorter than the control group (10.0 ± 6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

  10. Ultrasound guided electrical impedance tomography for 2D free-interface reconstruction

    Science.gov (United States)

    Liang, Guanghui; Ren, Shangjie; Dong, Feng

    2017-07-01

    The free-interface detection problem is normally seen in industrial or biological processes. Electrical impedance tomography (EIT) is a non-invasive technique with advantages of high-speed and low cost, and is a promising solution for free-interface detection problems. However, due to the ill-posed and nonlinear characteristics, the spatial resolution of EIT is low. To deal with the issue, an ultrasound guided EIT is proposed to directly reconstruct the geometric configuration of the target free-interface. In the method, the position of the central point of the target interface is measured by a pair of ultrasound transducers mounted at the opposite side of the objective domain, and then the position measurement is used as the prior information for guiding the EIT-based free-interface reconstruction. During the process, a constrained least squares framework is used to fuse the information from different measurement modalities, and the Lagrange multiplier-based Levenberg-Marquardt method is adopted to provide the iterative solution of the constraint optimization problem. The numerical results show that the proposed ultrasound guided EIT method for the free-interface reconstruction is more accurate than the single modality method, especially when the number of valid electrodes is limited.

  11. Ultrasound guided electrical impedance tomography for 2D free-interface reconstruction

    International Nuclear Information System (INIS)

    Liang, Guanghui; Ren, Shangjie; Dong, Feng

    2017-01-01

    The free-interface detection problem is normally seen in industrial or biological processes. Electrical impedance tomography (EIT) is a non-invasive technique with advantages of high-speed and low cost, and is a promising solution for free-interface detection problems. However, due to the ill-posed and nonlinear characteristics, the spatial resolution of EIT is low. To deal with the issue, an ultrasound guided EIT is proposed to directly reconstruct the geometric configuration of the target free-interface. In the method, the position of the central point of the target interface is measured by a pair of ultrasound transducers mounted at the opposite side of the objective domain, and then the position measurement is used as the prior information for guiding the EIT-based free-interface reconstruction. During the process, a constrained least squares framework is used to fuse the information from different measurement modalities, and the Lagrange multiplier-based Levenberg–Marquardt method is adopted to provide the iterative solution of the constraint optimization problem. The numerical results show that the proposed ultrasound guided EIT method for the free-interface reconstruction is more accurate than the single modality method, especially when the number of valid electrodes is limited. (paper)

  12. Dual-Modality Imaging of the Human Finger Joint Systems by Using Combined Multispectral Photoacoustic Computed Tomography and Ultrasound Computed Tomography

    Directory of Open Access Journals (Sweden)

    Yubin Liu

    2016-01-01

    Full Text Available We developed a homemade dual-modality imaging system that combines multispectral photoacoustic computed tomography and ultrasound computed tomography for reconstructing the structural and functional information of human finger joint systems. The fused multispectral photoacoustic-ultrasound computed tomography (MPAUCT system was examined by the phantom and in vivo experimental tests. The imaging results indicate that the hard tissues such as the bones and the soft tissues including the blood vessels, the tendon, the skins, and the subcutaneous tissues in the finger joints systems can be effectively recovered by using our multimodality MPAUCT system. The developed MPAUCT system is able to provide us with more comprehensive information of the human finger joints, which shows its potential for characterization and diagnosis of bone or joint diseases.

  13. Use of Mueller matrix polarimetry and optical coherence tomography in the characterization of cervical collagen anisotropy.

    Science.gov (United States)

    Chue-Sang, Joseph; Bai, Yuqiang; Stoff, Susan; Gonzalez, Mariacarla; Holness, Nola; Gomes, Jefferson; Jung, Ranu; Gandjbakhche, Amir; Chernomordik, Viktor V; Ramella-Roman, Jessica C

    2017-08-01

    Preterm birth (PTB) presents a serious medical health concern throughout the world. There is a high incidence of PTB in both developed and developing countries ranging from 11% to 15%, respectively. Recent research has shown that cervical collagen orientation and distribution changes during pregnancy may be useful in predicting PTB. Polarization imaging is an effective means to measure optical anisotropy in birefringent materials, such as the cervix's extracellular matrix. Noninvasive, full-field Mueller matrix polarimetry (MMP) imaging methodologies, and optical coherence tomography (OCT) imaging were used to assess cervical collagen content and structure in nonpregnant porcine cervices. We demonstrate that the highly ordered structure of the nonpregnant porcine cervix can be observed with MMP. Furthermore, when utilized ex vivo, OCT and MMP yield very similar results with a mean error of 3.46% between the two modalities. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. Plant photonics: application of optical coherence tomography to monitor defects and rots in onion

    International Nuclear Information System (INIS)

    Meglinski, I V; Terry, L A; Buranachai, C

    2010-01-01

    The incidence of physiological and/or pathological defects in many fresh produce types is still unacceptably high and accounts for a large proportion of waste. With increasing interest in food security their remains strong demand in developing reliable and cost effective technologies for non-destructive screening of internal defects and rots, these being deemed unacceptable by consumers. It is well recognized that the internal defects and structure of turbid scattering media can be effectively visualized by using optical coherence tomography (OCT). In the present study, the high spatial resolution and advantages of OCT have been demonstrated for imaging the skins and outer laminae (concentric tissue layers) of intact whole onion bulbs with a view to non-invasively visualizing potential incidence/severity of internal defects

  15. Single-shot parallel full range complex Fourier-domain optical coherence tomography

    International Nuclear Information System (INIS)

    Huang Bingjie; Bu Peng; Nan Nan; Wang Xiangzhao

    2011-01-01

    We present a method of parallel full range complex Fourier-domain optical coherence tomography (FDOCT) that is capable of acquiring an artifacts-free two-dimensional (2-D) cross-sectional image, i.e. a full range B-scan tomogram, by a single shot of 2-D CCD camera. This method is based on a spatial carrier technique, in which the spatial carrier-frequency is instantaneously introduced into the 2-D spectral interferogram registered in parallel FDOCT by using a grating-generated reference beam. The spatial-carrier-contained 2-D spectral interferogram is processed through Fourier transformation to obtain a complex 2-D spectral interferogram. From the 2-D complex spectral interferomgram, a full range B-scan tomogram is reconstructed. The principle of our method is confirmed by imaging an onion sample.

  16. Two-harmonic complex spectral-domain optical coherence tomography using achromatic sinusoidal phase modulation

    Science.gov (United States)

    Lu, Sheng-Hua; Huang, Siang-Ru; Chou, Che-Chung

    2018-03-01

    We resolve the complex conjugate ambiguity in spectral-domain optical coherence tomography (SD-OCT) by using achromatic two-harmonic method. Unlike previous researches, the optical phase of the fiber interferometer is modulated by an achromatic phase shifter based on an optical delay line. The achromatic phase modulation leads to a wavelength-independent scaling coefficient for the two harmonics. Dividing the mean absolute value of the first harmonic by that of the second harmonic in a B-scan interferogram directly gives the scaling coefficient. It greatly simplifies the determination of the magnitude ratio between the two harmonics without the need of third harmonic and cumbersome iterative calculations. The inverse fast Fourier transform of the complex-valued interferogram constructed with the scaling coefficient, first and second harmonics yields a full-range OCT image. Experimental results confirm the effectiveness of the proposed achromatic two-harmonic technique for suppressing the mirror artifacts in SD-OCT images.

  17. Photonic compressive sensing enabled data efficient time stretch optical coherence tomography

    Science.gov (United States)

    Mididoddi, Chaitanya K.; Wang, Chao

    2018-03-01

    Photonic time stretch (PTS) has enabled real time spectral domain optical coherence tomography (OCT). However, this method generates a torrent of massive data at GHz stream rate, which requires capturing as per Nyquist principle. If the OCT interferogram signal is sparse in Fourier domain, which is always true for samples with limited number of layers, it can be captured at lower (sub-Nyquist) acquisition rate as per compressive sensing method. In this work we report a data compressed PTS-OCT system based on photonic compressive sensing with 66% compression with low acquisition rate of 50MHz and measurement speed of 1.51MHz per depth profile. A new method has also been proposed to improve the system with all-optical random pattern generation, which completely avoids electronic bottleneck in traditional binary pseudorandom binary sequence (PRBS) generators.

  18. Optical coherence tomography in the diagnosis of dysplasia and adenocarcinoma in Barret's esophagus

    Science.gov (United States)

    Gladkova, N. D.; Zagaynova, E. V.; Zuccaro, G.; Kareta, M. V.; Feldchtein, F. I.; Balalaeva, I. V.; Balandina, E. B.

    2007-02-01

    Statistical analysis of endoscopic optical coherence tomography (EOCT) surveillance of 78 patients with Barrett's esophagus (BE) is presented in this study. The sensitivity of OCT device in retrospective open detection of early malignancy (including high grade dysplasia and intramucosal adenocarcinoma (IMAC)) was 75%, specificity 82%, diagnostic accuracy - 80%, positive predictive value- 60%, negative predictive value- 87%. In the open recognition of IMAC sensitivity was 81% and specificity were 85% each. Results of a blind recognition with the same material were similar: sensitivity - 77%, specificity 85%, diagnostic accuracy - 82%, positive predictive value- 70%, negative predictive value- 87%. As the endoscopic detection of early malignancy is problematic, OCT holds great promise in enhancing the diagnostic capability of clinical GI endoscopy.

  19. Fiber-optic polarization diversity detection for rotary probe optical coherence tomography.

    Science.gov (United States)

    Lee, Anthony M D; Pahlevaninezhad, Hamid; Yang, Victor X D; Lam, Stephen; MacAulay, Calum; Lane, Pierre

    2014-06-15

    We report a polarization diversity detection scheme for optical coherence tomography with a new, custom, miniaturized fiber coupler with single mode (SM) fiber inputs and polarization maintaining (PM) fiber outputs. The SM fiber inputs obviate matching the optical lengths of the X and Y OCT polarization channels prior to interference and the PM fiber outputs ensure defined X and Y axes after interference. Advantages for this scheme include easier alignment, lower cost, and easier miniaturization compared to designs with free-space bulk optical components. We demonstrate the utility of the detection system to mitigate the effects of rapidly changing polarization states when imaging with rotating fiber optic probes in Intralipid suspension and during in vivo imaging of human airways.

  20. A Novel Mach-Zehnder Interferometer Using Eccentric-Core Fiber Design for Optical Coherence Tomography.

    Science.gov (United States)

    Xiong, Qiao; Tong, Xinglin; Deng, Chengwei; Zhang, Cui; Wang, Pengfei; Zheng, Zhiyuan; Liu, Fang

    2018-05-13

    A novel Mach-Zehnder interferometer using eccentric-core fiber (ECF) design for optical coherence tomography (OCT) is proposed and demonstrated. Instead of the commercial single-mode fiber (SMF), the ECF is used as one interference arm of the implementation. Because of the offset location of the eccentric core, it is sensitive to directional bending and the optical path difference (OPD) of two interference arms can be adjusted with high precision. The birefringence of ECF is calculated and experimentally measured, which demonstrates the polarization sensitivity of the ECF proposed in the paper is similar to that of SMF. Such a structure can replace the reference optical delay line to form an all-fiber passive device. A mirror is used as a sample for analyzing the ECF bending responses of the system. Besides, four pieces of overlapping glass slides as sample are experimentally measured as well.

  1. Practical implementation of spectral-intensity dispersion-canceled optical coherence tomography with artifact suppression

    Science.gov (United States)

    Shirai, Tomohiro; Friberg, Ari T.

    2018-04-01

    Dispersion-canceled optical coherence tomography (OCT) based on spectral intensity interferometry was devised as a classical counterpart of quantum OCT to enhance the basic performance of conventional OCT. In this paper, we demonstrate experimentally that an alternative method of realizing this kind of OCT by means of two optical fiber couplers and a single spectrometer is a more practical and reliable option than the existing methods proposed previously. Furthermore, we develop a recipe for reducing multiple artifacts simultaneously on the basis of simple averaging and verify experimentally that it works successfully in the sense that all the artifacts are mitigated effectively and only the true signals carrying structural information about the sample survive.

  2. Defect inspection of actuator lenses using swept-source optical coherence tomography

    Science.gov (United States)

    Lee, Jaeyul; Shirazi, Muhammad Faizan; Park, Kibeom; Jeon, Mansik; Kim, Jeehyun

    2017-12-01

    Actuator lens industries have gained an enormous interest with the enhancement of various latest communication devices, such as mobile phone and notebooks. The quality of the aforementioned devices can be degraded due to the internal defects of actuator lenses. Therefore, in this study, we implemented swept-source optical coherence tomography (SS-OCT) system to inspect defects of actuator lenses. Owing to the high-resolution of the SS-OCT system, defected foreign substances between the actuator lenses, defective regions of lenses and surface stains were more clearly distinguished through three-dimensional (3D) and two-dimensional (2D) cross-sectional OCT images. Therefore, the implemented SS-OCT system can be considered as a potential application to defect inspection of actuator lens.

  3. Capillary red blood cell velocimetry by phase-resolved optical coherence tomography.

    Science.gov (United States)

    Tang, Jianbo; Erdener, Sefik Evren; Fu, Buyin; Boas, David A

    2017-10-01

    We present a phase-resolved optical coherence tomography (OCT) method to extend Doppler OCT for the accurate measurement of the red blood cell (RBC) velocity in cerebral capillaries. OCT data were acquired with an M-mode scanning strategy (repeated A-scans) to account for the single-file passage of RBCs in a capillary, which were then high-pass filtered to remove the stationary component of the signal to ensure an accurate measurement of phase shift of flowing RBCs. The angular frequency of the signal from flowing RBCs was then quantified from the dynamic component of the signal and used to calculate the axial speed of flowing RBCs in capillaries. We validated our measurement by RBC passage velocimetry using the signal magnitude of the same OCT time series data.

  4. Full-Field Optical Coherence Tomography as a Diagnosis Tool: Recent Progress with Multimodal Imaging

    Directory of Open Access Journals (Sweden)

    Olivier Thouvenin

    2017-03-01

    Full Text Available Full-field optical coherence tomography (FF-OCT is a variant of OCT that is able to register 2D en face views of scattering samples at a given depth. Thanks to its superior resolution, it can quickly reveal information similar to histology without the need to physically section the sample. Sensitivity and specificity levels of diagnosis performed with FF-OCT are 80% to 95% of the equivalent histological diagnosis performances and could therefore benefit from improvement. Therefore, multimodal systems have been designed to increase the diagnostic performance of FF-OCT. In this paper, we will discuss which contrasts can be measured with such multimodal systems in the context of ex vivo biological tissue examination. We will particularly emphasize three multimodal combinations to measure the tissue mechanics, dynamics, and molecular content respectively.

  5. Correction of distortions in optical coherence tomography imaging of the eye

    Energy Technology Data Exchange (ETDEWEB)

    Podoleanu, Adrian [Applied Optics Group, University of Kent, Canterbury (United Kingdom); Charalambous, Ismini [Applied Optics Group, University of Kent, Canterbury (United Kingdom); Plesea, Lucian [Applied Optics Group, University of Kent, Canterbury (United Kingdom); Dogariu, Aristide [School of Optics, CREOL, University of Central Florida, Orlando, FL (United States); Rosen, Richard [Advanced Retinal Imaging Center, New York Eye and Ear Infirmary, NY (United States)

    2004-04-07

    Optical coherence tomography (OCT) images are affected by artefacts. These artefacts are the result of different factors such as refraction, curvature of the intermediate layers up to the depth of interest and the scanning procedure. The effect of such errors is different, depending on the way the image is acquired, either en-face or longitudinal OCT. We quantify the distortions by evaluating a lateral and an axial error. These measure the lateral and axial deviations of each image point from the object point inside the tissue. We show that the axial distortion can be larger than the achievable depth resolution in modern OCT systems. We have investigated these errors in imaging different tissue: cornea and retina in vivo and an intraocular lens in vitro.

  6. In vivo Evaluation of Enamel Dental Restoration Interface by Optical Coherence Tomography

    International Nuclear Information System (INIS)

    Mota, Claudia C. B. O.; Gomes, Anderson S. L.; Kashyap, Hannah U. K. S.; Kyotoku, Bernardo B. C.

    2009-01-01

    In this work, we report in vivo application of Optical Coherence Tomography (OCT) to assess dental restorations in humans. After approval by the Ethical Committee in Humans Research of the Federal University of Pernambuco, thirty patients with resin composite restorations performed in anterior teeth were selected. The patients were clinically evaluated, and OCT was performed. Images were obtained using OCT operating in the spectral domain, with a 840 nm super luminescent diode light source (spectral width of 50 nm, fiber output power 25mW and a measured spatial resolution of 10 μm). The image acquisition time was less than one second. The results were analyzed with respect to the integrity and marginal adaptation of the restoration. Using appropriate software, the lesion region can be exactly located and a new restoration procedure can be carried out. We have shown that OCT is more than adequate in clinical practice to assess dental restorations. (Author)

  7. The lymphatic mechanisms of brain cleaning: application of optical coherence tomography and fluorescence microscopy

    Science.gov (United States)

    Glushkovskaya-Semyachkina, O.; Abdurashitov, A.; Fedosov, I.; Namykin, A.; Pavlov, A.; Shirokov, A.; Shushunova, N.; Sindeeva, O.; Khorovodov, A.; Ulanova, M.; Sagatova, V.; Agranovich, I.; Bodrova, A.; Kurths, J.

    2018-04-01

    Here we studied the role of cerebral lymphatic system in the brain clearing using intraparenchymal injection of Evans Blue and gold nanorods assessed by optical coherent tomography and fluorescence microscopy. Our data clearly show that the cerebral lymphatic system plays an important role in the brain cleaning via meningeal lymphatic vessels but not cerebral veins. Meningeal lymphatic vessels transport fluid from the brain into the deep cervical node, which is the first anatomical "station" for lymph outflow from the brain. The lymphatic processes underlying brain clearing are more slowly vs. peripheral lymphatics. These results shed light on the lymphatic mechanisms responsible for brain clearing as well as interaction between the intra- and extracranial lymphatic compartment.

  8. Optical coherence tomography (OCT) leading to more insight into cochlear mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Egbert de [Academic Medical Centre, University of Amsterdam, Amsterdam (Netherlands); Oregon Health & Science University, Portland, Oregon (United States); Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L. [Oregon Health & Science University, Portland, Oregon (United States)

    2015-12-31

    Optical Coherence Tomography (OCT) was used to measure vibrations of the basilar membrane (BM) and the Reticular Lamina (RL) in the cochlea of the guinea pig, at frequencies up to 25 kHz. Because of the difficulty of the experiments the data have limited sets of parameters and are subject to high noise levels. In a viable guinea-pig cochlea, the RL moves in the region of maximum response with a larger amplitude than the BM. We cannot rule out that some of that difference is due to a geometrical factor. We also found a consistent increase of this amplitude difference with frequency, which points to a low-pass filtering process. That process might be linked to the mass of the fluid contained in the Organ of Corti channel (OoC channel)

  9. Morphology and epidermal thickness of normal skin imaged by optical coherence tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Morsy, Hanan A.; Thrane, Lars

    2008-01-01

    colour. Methods: OCT imaging is based on infrared light reflection/backscatter from tissue. PS-OCT detects birefringence of tissue. Imaging was performed in 12 skin regions. ET was calculated from the OCT images. Results: Normal skin has a layered structure. Layering is less pronounced in adults......Background: Optical coherence tomography (OCT) is an optical imaging technology with a potential in the non-invasive diagnosis of skin cancer. To identify skin pathologies using OCT, it is of prime importance to establish baseline morphological features of normal skin. Aims: The aim of this study...... is to describe normal skin morphology using OCT and polarization-sensitive OCT (PS-OCT), which is a way of representing birefringent tissue such as collagen in OCT images. Anatomical locations in 20 healthy volunteers were imaged, and epidermal thickness (ET) was measured and compared to age, gender and skin...

  10. High-speed spectral domain optical coherence tomography using non-uniform fast Fourier transform

    Science.gov (United States)

    Chan, Kenny K. H.; Tang, Shuo

    2010-01-01

    The useful imaging range in spectral domain optical coherence tomography (SD-OCT) is often limited by the depth dependent sensitivity fall-off. Processing SD-OCT data with the non-uniform fast Fourier transform (NFFT) can improve the sensitivity fall-off at maximum depth by greater than 5dB concurrently with a 30 fold decrease in processing time compared to the fast Fourier transform with cubic spline interpolation method. NFFT can also improve local signal to noise ratio (SNR) and reduce image artifacts introduced in post-processing. Combined with parallel processing, NFFT is shown to have the ability to process up to 90k A-lines per second. High-speed SD-OCT imaging is demonstrated at camera-limited 100 frames per second on an ex-vivo squid eye. PMID:21258551

  11. Secure fingerprint identification based on structural and microangiographic optical coherence tomography.

    Science.gov (United States)

    Liu, Xuan; Zaki, Farzana; Wang, Yahui; Huang, Qiongdan; Mei, Xin; Wang, Jiangjun

    2017-03-10

    Optical coherence tomography (OCT) allows noncontact acquisition of fingerprints and hence is a highly promising technology in the field of biometrics. OCT can be used to acquire both structural and microangiographic images of fingerprints. Microangiographic OCT derives its contrast from the blood flow in the vasculature of viable skin tissue, and microangiographic fingerprint imaging is inherently immune to fake fingerprint attack. Therefore, dual-modality (structural and microangiographic) OCT imaging of fingerprints will enable more secure acquisition of biometric data, which has not been investigated before. Our study on fingerprint identification based on structural and microangiographic OCT imaging is, we believe, highly innovative. In this study, we performed OCT imaging study for fingerprint acquisition, and demonstrated the capability of dual-modality OCT imaging for the identification of fake fingerprints.

  12. Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography

    International Nuclear Information System (INIS)

    Unterhuber, A; Povazay, B; Bizheva, K; Hermann, B; Sattmann, H; Stingl, A; Le, T; Seefeld, M; Menzel, R; Preusser, M; Budka, H; Schubert, Ch; Reitsamer, H; Ahnelt, P K; Morgan, J E; Cowey, A; Drexler, W

    2004-01-01

    Novel ultra-broad bandwidth light sources enabling unprecedented sub-2 μm axial resolution over the 400 nm-1700 nm wavelength range have been developed and evaluated with respect to their feasibility for clinical ultrahigh resolution optical coherence tomography (UHR OCT) applications. The state-of-the-art light sources described here include a compact Kerr lens mode locked Ti:sapphire laser (λ c = 785 nm, Δλ = 260 nm, P out = 50 mW) and different nonlinear fibre-based light sources with spectral bandwidths (at full width at half maximum) up to 350 nm at λ c = 1130 nm and 470 nm at λ c = 1375 nm. In vitro UHR OCT imaging is demonstrated at multiple wavelengths in human cancer cells, animal ganglion cells as well as in neuropathologic and ophthalmic biopsies in order to compare and optimize UHR OCT image contrast, resolution and penetration depth

  13. Microperimetry and optical coherent tomography in patients operated on y the conventional retinal detachment surgery

    International Nuclear Information System (INIS)

    Guerra Garcia, Roberto Alejandro; Rodriguez Rodriguez, Beatriz N; Eguia Martinez, Frank

    2008-01-01

    A descriptive study was made to determine the visual acuity, microperimetry and optical coherence tomography in patients operated on by the conventional rhegmatogenous retinal detachment at 'Ramon Pando Ferrer' Cuban Ophthalmologic Institute from October 2006 to March 2007. Twenty six patients, who had gone to the hospital with normal values in ophthalmoscopy and biomicroscopy and three-six months of disease development. Better corrected visual acuity, fixation, average sensitivity, morphology and macular thickness were obtained after surgery. Average visual acuity was 0,41 and fixation was stable in most of patients; average retinal sensitivity was 11 decibels. The most frequent finding was serum detachment. Average macular thickness was 246,3 micras. There was no statistical relation between preoperative time of disease development and the macular characteristics of detachment in these tests. (Author)

  14. Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study.

    Science.gov (United States)

    Moschos, Marilita M; Nitoda, Eirini; Chatziralli, Irini P; Gatzioufas, Zisis; Koutsandrea, Chryssanthi; Kitsos, George

    2015-01-01

    This study was conducted to evaluate the macular status of patients treated with hydroxychloroquine before and after cessation of treatment. Forty-two patients with systemic lupus erythematosus underwent ocular examination based on visual acuity evaluation, optical coherence tomography retinal thickness measurements, and multifocal electroretinography (mfERG) records at first visit. The tests were repeated 6 months after treatment withdrawal and compared to the findings at their first visit. Mean visual acuity (measured in log minimum angle of resolution) of both eyes was statistically increased after hydroxychloroquine discontinuation (difference in means: 0.06 [Phydroxychloroquine improves along with the amplitudes of the mfERG responses 6 months after discontinuation of the drug, but no difference in retinal thickness is identified.

  15. Application of optical coherence tomography for noninvasive blood glucose monitoring during hyperglycemia

    Science.gov (United States)

    Larin, Kirill V.; Ashitkov, Taras V.; Motamedi, Massoud; Esenaliev, Rinat O.

    2003-10-01

    Approximately 14 million people in the USA and more than 140 million people worldwide suffer from Diabetes Mellitus. The current glucose sensing technique involves a finger puncture several times a day to obtain a droplet of blood for chemical analysis. Recently we proposed to use optical coherence tomography (OCT) for continuous noninvasive blood glucose sensing through skin. In this paper we tested the OCT technique for noninvasive monitoring of blood glucose concentration in lip tissue of New Zealand rabbits and Yucatan micropigs during glucose clamping experiments. Obtained results show good agreement with results obtained in skin studies, good correlation of changes in the OCT signal slope measured at the depth of 250 to 500 μm with changes in blood glucose concentration, and higher stability of the OCT data points than that obtained from skin.

  16. Integration of Optical Coherence Tomography Scan Patterns to Augment Clinical Data Suite

    Science.gov (United States)

    Mason, S.; Patel, N.; Van Baalen, M.; Tarver, W.; Otto, C.; Samuels, B.; Koslovsky, M.; Schaefer, C.; Taiym, W.; Wear, M.; hide

    2018-01-01

    Vision changes identified in long duration spaceflight astronauts has led Space Medicine at NASA to adopt a more comprehensive clinical monitoring protocol. Optical Coherence Tomography (OCT) was recently implemented at NASA, including on board the International Space Station in 2013. NASA is collaborating with Heidelberg Engineering to increase the fidelity of the current OCT data set by integrating the traditional circumpapillary OCT image with radial and horizontal block images at the optic nerve head. The retinal nerve fiber layer was segmented by two experienced individuals. Intra-rater (N=4 subjects and 70 images) and inter-rater (N=4 subjects and 221 images) agreement was performed. The results of this analysis and the potential benefits will be presented.

  17. Co-registration of optical coherence tomography and X-ray angiography in percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Hebsgaard, Lasse; Nielsen, Troels Munck; Tu, Shengxian

    2014-01-01

    Background Intracoronary imaging provides accurate lesion delineation and precise measurements for sizing and positioning of coronary stents. During percutaneous coronary intervention (PCI), it may be challenging to identify corresponding segments between intracoronary imaging and angiography....... Computer based online co-registration may aid the target segment identification. Methods The DOCTOR fusion study was a prospective, single arm, observational study including patients admitted for elective PCI. Optical coherence tomography (OCT) was acquired pre-stent implantation for sizing of stents...... to the computer-based co-registration, segments of the target lesion indicated on OCT were left uncovered by stent in 14 patients (70%). Conclusion Computer based online co-registration of OCT and angiography is feasible. Frequent inaccuracies in operator based registration indicate that computer aided co...

  18. Extending the Effective Ranging Depth of Spectral Domain Optical Coherence Tomography by Spatial Frequency Domain Multiplexing

    Directory of Open Access Journals (Sweden)

    Tong Wu

    2016-11-01

    Full Text Available We present a spatial frequency domain multiplexing method for extending the imaging depth range of a spectral domain optical coherence tomography (SDOCT system without any expensive device. This method uses two galvo scanners with different pivot-offset distances in two independent reference arms for spatial frequency modulation and multiplexing. The spatial frequency contents corresponding to different depth regions of the sample can be shifted to different frequency bands. The spatial frequency domain multiplexing SDOCT system provides an approximately 1.9-fold increase in the effective ranging depth compared with that of a conventional full-range SDOCT system. The reconstructed images of phantom and biological tissue demonstrate the expected increase in ranging depth. The parameters choice criterion for this method is discussed.

  19. Artificial fingerprint recognition by using optical coherence tomography with autocorrelation analysis

    Science.gov (United States)

    Cheng, Yezeng; Larin, Kirill V.

    2006-12-01

    Fingerprint recognition is one of the most widely used methods of biometrics. This method relies on the surface topography of a finger and, thus, is potentially vulnerable for spoofing by artificial dummies with embedded fingerprints. In this study, we applied the optical coherence tomography (OCT) technique to distinguish artificial materials commonly used for spoofing fingerprint scanning systems from the real skin. Several artificial fingerprint dummies made from household cement and liquid silicone rubber were prepared and tested using a commercial fingerprint reader and an OCT system. While the artificial fingerprints easily spoofed the commercial fingerprint reader, OCT images revealed the presence of them at all times. We also demonstrated that an autocorrelation analysis of the OCT images could be potentially used in automatic recognition systems.

  20. Magneto-motive detection of tissue-based macrophages by differential phase optical coherence tomography.

    Science.gov (United States)

    Oh, Junghwan; Feldman, Marc D; Kim, Jihoon; Kang, Hyun Wook; Sanghi, Pramod; Milner, Thomas E

    2007-03-01

    A novel method to detect tissue-based macrophages using a combination of superparamagnetic iron oxide (SPIO) nanoparticles and differential phase optical coherence tomography (DP-OCT) with an external oscillating magnetic field is reported. Magnetic force acting on iron-laden tissue-based macrophages was varied by applying a sinusoidal current to a solenoid containing a conical iron core that substantially focused and increased magnetic flux density. Nanoparticle motion was detected with DP-OCT, which can detect tissue movement with nanometer resolution. Frequency response of iron-laden tissue movement was twice the modulation frequency since the magnetic force is proportional to the product of magnetic flux density and gradient. Results of our experiments indicate that DP-OCT can be used to identify tissue-based macrophage when excited by an external focused oscillating magnetic field. (c) 2007 Wiley-Liss, Inc

  1. Wide-field optical coherence tomography based microangiography for retinal imaging

    Science.gov (United States)

    Zhang, Qinqin; Lee, Cecilia S.; Chao, Jennifer; Chen, Chieh-Li; Zhang, Thomas; Sharma, Utkarsh; Zhang, Anqi; Liu, Jin; Rezaei, Kasra; Pepple, Kathryn L.; Munsen, Richard; Kinyoun, James; Johnstone, Murray; van Gelder, Russell N.; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography angiography (OCTA) allows for the evaluation of functional retinal vascular networks without a need for contrast dyes. For sophisticated monitoring and diagnosis of retinal diseases, OCTA capable of providing wide-field and high definition images of retinal vasculature in a single image is desirable. We report OCTA with motion tracking through an auxiliary real-time line scan ophthalmoscope that is clinically feasible to image functional retinal vasculature in patients, with a coverage of more than 60 degrees of retina while still maintaining high definition and resolution. We demonstrate six illustrative cases with unprecedented details of vascular involvement in retinal diseases. In each case, OCTA yields images of the normal and diseased microvasculature at all levels of the retina, with higher resolution than observed with fluorescein angiography. Wide-field OCTA technology will be an important next step in augmenting the utility of OCT technology in clinical practice.

  2. In vivo integrated photoacoustic ophthalmoscopy, optical coherence tomography, and scanning laser ophthalmoscopy for retinal imaging

    Science.gov (United States)

    Song, Wei; Zhang, Rui; Zhang, Hao F.; Wei, Qing; Cao, Wenwu

    2012-12-01

    The physiological and pathological properties of retina are closely associated with various optical contrasts. Hence, integrating different ophthalmic imaging technologies is more beneficial in both fundamental investigation and clinical diagnosis of several blinding diseases. Recently, photoacoustic ophthalmoscopy (PAOM) was developed for in vivo retinal imaging in small animals, which demonstrated the capability of imaging retinal vascular networks and retinal pigment epithelium (RPE) at high sensitivity. We combined PAOM with traditional imaging modalities, such as fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), and auto-fluorescence scanning laser ophthalmoscopy (AF-SLO), for imaging rats and mice. The multimodal imaging system provided more comprehensive evaluation of the retina based on the complementary imaging contrast mechanisms. The high-quality retinal images show that the integrated ophthalmic imaging system has great potential in the investigation of blinding disorders.

  3. Optical coherence tomography and subclinical optical neuritis in longitudinally extensive transverse myelitis

    Directory of Open Access Journals (Sweden)

    Prakash Kumar Sinha

    2017-01-01

    Full Text Available Objective: The aim is to compare the retinal nerve fiber layer (RNFL thickness of longitudinally extensive transverse myelitis (LETM eyes without previous optic neuritis with that of healthy control subjects. Methods: Over 20 LETM eyes and 20 normal control eyes were included in the study and subjected to optical coherence tomography to evaluate and compare the RNFL thickness. Result: Significant RNFL thinning was observed at 8 o'clock position in LETM eyes as compared to the control eyes (P = 0.038. No significant differences were seen in other RNFL measurements. Conclusion: Even in the absence of previous optic neuritis LETM can lead to subclinical axonal damage leading to focal RNFL thinning.

  4. Optical coherence tomography: Monte Carlo simulation and improvement by optical amplification

    DEFF Research Database (Denmark)

    Tycho, Andreas

    2002-01-01

    An advanced novel Monte Carlo simulation model of the detection process of an optical coherence tomography (OCT) system is presented. For the first time it is shown analytically that the applicability of the incoherent Monte Carlo approach to model the heterodyne detection process of an OCT system...... is firmly justified. This is obtained by calculating the heterodyne mixing of the reference and sample beams in a plane conjugate to the discontinuity in the sample probed by the system. Using this approach, a novel expression for the OCT signal is derived, which only depends uopon the intensity...... flexibility of Monte Carlo simulations, this new model is demonstrated to be excellent as a numerical phantom, i.e., as a substitute for otherwise difficult experiments. Finally, a new model of the signal-to-noise ratio (SNR) of an OCT system with optical amplification of the light reflected from the sample...

  5. Microscope-integrated optical coherence tomography for image-aided positioning of glaucoma surgery

    Science.gov (United States)

    Li, Xiqi; Wei, Ling; Dong, Xuechuan; Huang, Ping; Zhang, Chun; He, Yi; Shi, Guohua; Zhang, Yudong

    2015-07-01

    Most glaucoma surgeries involve creating new aqueous outflow pathways with the use of a small surgical instrument. This article reported a microscope-integrated, real-time, high-speed, swept-source optical coherence tomography system (SS-OCT) with a 1310-nm light source for glaucoma surgery. A special mechanism was designed to produce an adjustable system suitable for use in surgery. A two-graphic processing unit architecture was used to speed up the data processing and real-time volumetric rendering. The position of the surgical instrument can be monitored and measured using the microscope and a grid-inserted image of the SS-OCT. Finally, experiments were simulated to assess the effectiveness of this integrated system. Experimental results show that this system is a suitable positioning tool for glaucoma surgery.

  6. Functional imaging and assessment of the glucose diffusion rate in epithelial tissues in optical coherence tomography

    International Nuclear Information System (INIS)

    Larin, K V; Tuchin, V V

    2008-01-01

    Functional imaging, monitoring and quantitative description of glucose diffusion in epithelial and underlying stromal tissues in vivo and controlling of the optical properties of tissues are extremely important for many biomedical applications including the development of noninvasive or minimally invasive glucose sensors as well as for therapy and diagnostics of various diseases, such as cancer, diabetic retinopathy, and glaucoma. Recent progress in the development of a noninvasive molecular diffusion biosensor based on optical coherence tomography (OCT) is described. The diffusion of glucose was studied in several epithelial tissues both in vitro and in vivo. Because OCT provides depth-resolved imaging of tissues with high in-depth resolution, the glucose diffusion is described not only as a function of time but also as a function of depth. (special issue devoted to application of laser technologies in biophotonics and biomedical studies)

  7. Use of Mueller matrix polarimetry and optical coherence tomography in the characterization of cervical collagen anisotropy

    Science.gov (United States)

    Chue-Sang, Joseph; Bai, Yuqiang; Stoff, Susan; Gonzalez, Mariacarla; Holness, Nola; Gomes, Jefferson; Jung, Ranu; Gandjbakhche, Amir; Chernomordik, Viktor V.; Ramella-Roman, Jessica C.

    2017-08-01

    Preterm birth (PTB) presents a serious medical health concern throughout the world. There is a high incidence of PTB in both developed and developing countries ranging from 11% to 15%, respectively. Recent research has shown that cervical collagen orientation and distribution changes during pregnancy may be useful in predicting PTB. Polarization imaging is an effective means to measure optical anisotropy in birefringent materials, such as the cervix's extracellular matrix. Noninvasive, full-field Mueller matrix polarimetry (MMP) imaging methodologies, and optical coherence tomography (OCT) imaging were used to assess cervical collagen content and structure in nonpregnant porcine cervices. We demonstrate that the highly ordered structure of the nonpregnant porcine cervix can be observed with MMP. Furthermore, when utilized ex vivo, OCT and MMP yield very similar results with a mean error of 3.46% between the two modalities.

  8. Swept source optical coherence tomography of objects with arbitrary reflectivity profiles

    Science.gov (United States)

    Mezgebo, Biniyam; Nagib, Karim; Fernando, Namal; Kordi, Behzad; Sherif, Sherif

    2018-03-01

    Swept Source optical coherence tomography (SS-OCT) has become a well established imaging modality for both medical and industrial diagnostic applications. A cross-sectional SS-OCT image is obtained by applying an inverse discrete Fourier transform (DFT) to axial interferogram measured in the frequency domain (k-space). Fourier inversion of the obtained interferogram typically produces a potentially overlapping conjugate mirror image, whose overlap could be avoided by restricting the object to have its highest reflectivity at its surface. However, this restriction may not be fulfilled when imaging a very thin object that is placed on a highly reflective surface, or imaging an object containing a contrast agent with high reflectivity. In this paper, we show that oversampling of the SS-OCT signal in k-space would overcome the need for such restriction on the object. Our result is demonstrated using SS-OCT images of Axolotl salamander eggs.

  9. Quantifying Optical Microangiography Images Obtained from a Spectral Domain Optical Coherence Tomography System

    Directory of Open Access Journals (Sweden)

    Roberto Reif

    2012-01-01

    Full Text Available The blood vessel morphology is known to correlate with several diseases, such as cancer, and is important for describing several tissue physiological processes, like angiogenesis. Therefore, a quantitative method for characterizing the angiography obtained from medical images would have several clinical applications. Optical microangiography (OMAG is a method for obtaining three-dimensional images of blood vessels within a volume of tissue. In this study we propose to quantify OMAG images obtained with a spectral domain optical coherence tomography system. A technique for determining three measureable parameters (the fractal dimension, the vessel length fraction, and the vessel area density is proposed and validated. Finally, the repeatability for acquiring OMAG images is determined, and a new method for analyzing small areas from these images is proposed.

  10. Automated detection of photoreceptor disruption in mild diabetic retinopathy on volumetric optical coherence tomography.

    Science.gov (United States)

    Wang, Zhuo; Camino, Acner; Zhang, Miao; Wang, Jie; Hwang, Thomas S; Wilson, David J; Huang, David; Li, Dengwang; Jia, Yali

    2017-12-01

    Diabetic retinopathy is a pathology where microvascular circulation abnormalities ultimately result in photoreceptor disruption and, consequently, permanent loss of vision. Here, we developed a method that automatically detects photoreceptor disruption in mild diabetic retinopathy by mapping ellipsoid zone reflectance abnormalities from en face optical coherence tomography images. The algorithm uses a fuzzy c-means scheme with a redefined membership function to assign a defect severity level on each pixel and generate a probability map of defect category affiliation. A novel scheme of unsupervised clustering optimization allows accurate detection of the affected area. The achieved accuracy, sensitivity and specificity were about 90% on a population of thirteen diseased subjects. This method shows potential for accurate and fast detection of early biomarkers in diabetic retinopathy evolution.

  11. Fast Industrial Inspection of Optical Thin Film Using Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Muhammad Faizan Shirazi

    2016-09-01

    Full Text Available An application of spectral domain optical coherence tomography (SD-OCT was demonstrated for a fast industrial inspection of an optical thin film panel. An optical thin film sample similar to a liquid crystal display (LCD panel was examined. Two identical SD-OCT systems were utilized for parallel scanning of a complete sample in half time. Dual OCT inspection heads were utilized for transverse (fast scanning, while a stable linear motorized translational stage was used for lateral (slow scanning. The cross-sectional and volumetric images of an optical thin film sample were acquired to detect the defects in glass and other layers that are difficult to observe using visual inspection methods. The rapid inspection enabled by this setup led to the early detection of product defects on the manufacturing line, resulting in a significant improvement in the quality assurance of industrial products.

  12. Microstructural abnormalities in MEWDS demonstrated by ultrahigh resolution optical coherence tomography.

    Science.gov (United States)

    Nguyen, My Hanh T; Witkin, Andre J; Reichel, Elias; Ko, Tony H; Fujimoto, James G; Schuman, Joel S; Duker, Jay S

    2007-01-01

    Histopathological studies of acute multiple evanescent white dot syndrome (MEWDS) have not been reported because of the transient and benign nature of the disease. Ultrahigh resolution optical coherence tomography (UHR-OCT), capable of high resolution in vivo imaging, offers a unique opportunity to visualize retinal microstructure in the disease. UHR-OCT images of the maculae of five patients with MEWDS were obtained and analyzed. Diagnosis was based on clinical presentation, examination, visual field testing, and angiography. UHR-OCT revealed disturbances in the photoreceptor inner/outer segment junction (IS/OS) in each of the five patients (six eyes) with MEWDS. In addition, thinning of the outer nuclear layer was seen in the case of recurrent MEWDS, suggesting that repeated episodes of MEWDS may result in photoreceptor atrophy. Subtle disruptions of the photoreceptor IS/OS are demonstrated in all eyes affected by MEWDS. UHR-OCT may be a useful adjunct to diagnosis and monitoring of MEWDS.

  13. Artificial neural network techniques to improve the ability of optical coherence tomography to detect optic neuritis.

    Science.gov (United States)

    Garcia-Martin, Elena; Herrero, Raquel; Bambo, Maria P; Ara, Jose R; Martin, Jesus; Polo, Vicente; Larrosa, Jose M; Garcia-Feijoo, Julian; Pablo, Luis E

    2015-01-01

    To analyze the ability of Spectralis optical coherence tomography (OCT) to detect multiple sclerosis (MS) and to distinguish MS eyes with antecedent optic neuritis (ON). To analyze the capability of artificial neural network (ANN) techniques to improve the diagnostic precision. MS patients and controls were enrolled (n = 217). OCT was used to determine the 768 retinal nerve fiber layer thicknesses. Sensitivity and specificity were evaluated to test the ability of OCT to discriminate between MS and healthy eyes, and between MS with and without antecedent ON using ANN. Using ANN technique multilayer perceptrons, OCT could detect MS with a sensitivity of 89.3%, a specificity of 87.6%, and a diagnostic precision of 88.5%. Compared with the OCT-provided parameters, the ANN had a better sensitivity-specificity balance. ANN technique improves the capability of Spectralis OCT to detect MS disease and to distinguish MS eyes with or without antecedent ON.

  14. ELHnet: a convolutional neural network for classifying cochlear endolymphatic hydrops imaged with optical coherence tomography.

    Science.gov (United States)

    Liu, George S; Zhu, Michael H; Kim, Jinkyung; Raphael, Patrick; Applegate, Brian E; Oghalai, John S

    2017-10-01

    Detection of endolymphatic hydrops is important for diagnosing Meniere's disease, and can be performed non-invasively using optical coherence tomography (OCT) in animal models as well as potentially in the clinic. Here, we developed ELHnet, a convolutional neural network to classify endolymphatic hydrops in a mouse model using learned features from OCT images of mice cochleae. We trained ELHnet on 2159 training and validation images from 17 mice, using only the image pixels and observer-determined labels of endolymphatic hydrops as the inputs. We tested ELHnet on 37 images from 37 mice that were previously not used, and found that the neural network correctly classified 34 of the 37 mice. This demonstrates an improvement in performance from previous work on computer-aided classification of endolymphatic hydrops. To the best of our knowledge, this is the first deep CNN designed for endolymphatic hydrops classification.

  15. Noninvasive measurement of glucose concentration on human fingertip by optical coherence tomography

    Science.gov (United States)

    Chen, Tseng-Lin; Lo, Yu-Lung; Liao, Chia-Chi; Phan, Quoc-Hung

    2018-04-01

    A method is proposed for determining the glucose concentration on the human fingertip by extracting two optical parameters, namely the optical rotation angle and the depolarization index, using a Mueller optical coherence tomography technique and a genetic algorithm. The feasibility of the proposed method is demonstrated by measuring the optical rotation angle and depolarization index of aqueous glucose solutions with low and high scattering, respectively. It is shown that for both solutions, the optical rotation angle and depolarization index vary approximately linearly with the glucose concentration. As a result, the ability of the proposed method to obtain the glucose concentration by means of just two optical parameters is confirmed. The practical applicability of the proposed technique is demonstrated by measuring the optical rotation angle and depolarization index on the human fingertip of healthy volunteers under various glucose conditions.

  16. Qualitative investigation of fresh human scalp hair with full-field optical coherence tomography

    Science.gov (United States)

    Choi, Woo June; Pi, Long-Quan; Min, Gihyeon; Lee, Won-Soo; Lee, Byeong Ha

    2012-03-01

    We have investigated depth-resolved cellular structures of unmodified fresh human scalp hairs with ultrahigh-resolution full-field optical coherence tomography (FF-OCT). The Linnik-type white light interference microscope has been home-implemented to observe the micro-internal layers of human hairs in their natural environment. In hair shafts, FF-OCT has qualitatively revealed the cellular hair compartments of cuticle and cortex layers involved in keratin filaments and melanin granules. No significant difference between black and white hair shafts was observed except for absence of only the melanin granules in the white hair, reflecting that the density of the melanin granules directly affects the hair color. Anatomical description of plucked hair bulbs was also obtained with the FF-OCT in three-dimensions. We expect this approach will be useful for evaluating cellular alteration of natural hairs on cosmetic assessment or diagnosis of hair diseases.

  17. In vivo photothermal optical coherence tomography of endogenous and exogenous contrast agents in the eye.

    Science.gov (United States)

    Lapierre-Landry, Maryse; Gordon, Andrew Y; Penn, John S; Skala, Melissa C

    2017-08-23

    Optical coherence tomography (OCT) has become a standard-of-care in retinal imaging. OCT allows non-invasive imaging of the tissue structure but lacks specificity to contrast agents that could be used for in vivo molecular imaging. Photothermal OCT (PT-OCT) is a functional OCT-based technique that has been developed to detect absorbers in a sample. We demonstrate in vivo PT-OCT in the eye for the first time on both endogenous (melanin) and exogenous (gold nanorods) absorbers. Pigmented mice and albino mice (n = 6 eyes) were used to isolate the photothermal signal from the melanin in the retina. Pigmented mice with laser-induced choroidal neovascularization lesions (n = 7 eyes) were also imaged after a systemic injection of gold nanorods to observe their passive accumulation in the retina. This experiment demonstrates the feasibility of PT-OCT to image the distribution of both endogenous and exogenous absorbers in the mouse retina.

  18. Intraoperative imaging of pediatric vocal fold lesions using optical coherence tomography

    Science.gov (United States)

    Benboujja, Fouzi; Garcia, Jordan A.; Beaudette, Kathy; Strupler, Mathias; Hartnick, Christopher J.; Boudoux, Caroline

    2016-01-01

    Optical coherence tomography (OCT) has been previously identified as a promising tool for exploring laryngeal pathologies in adults. Here, we present an OCT handheld probe dedicated to imaging the unique geometry involved in pediatric laryngoscopy. A vertical cavity surface emitting laser-based wavelength-swept OCT system operating at 60 frames per second was coupled to the probe to acquire three-dimensional (3-D) volumes in vivo. In order to evaluate the performance of the proposed probe and system, we imaged pediatric vocal fold lesions of patients going under direct laryngoscopy. Through this in vivo study, we extracted OCT features characterizing each pediatric vocal fold lesion, which shows a great potential for noninvasive laryngeal lesion discrimination. We believe OCT vocal fold examination in 3-D will result in improved knowledge of the pediatric anatomy and could aid in managing pediatric laryngeal diseases.

  19. Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hamid Pahlevaninezhad

    2014-09-01

    Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

  20. Structural characterization on in vitro porcine skin treated by ablative fractional laser using optical coherence tomography

    Science.gov (United States)

    Feng, Kairui; Zhou, Kanheng; Ling, Yuting; O'Mahoney, Paul; Ewan, Eadie; Ibbotson, Sally H.; Li, Chunhui; Huang, Zhihong

    2018-02-01

    Ablative fractional skin laser is widely applied for various skin conditions, especially for cosmetic repairing and promoting the located drug delivery. Although the influence of laser treatment over the skin has been explored before in means of excision and biopsy with microscopy, these approaches are invasive, only morphological and capable of distorting the skin. In this paper the authors use fresh porcine skin samples irradiated by the lasers, followed by detected by using Optical Coherence Tomography (OCT). This advanced optical technique has the ability to present the high resolution structure image of treated sample. The results shows that laser beams can produce holes left on the surface after the irradiation. The depth of holes can be affected by changes of laser energy while the diameter of holes have no corresponding relation. Plus, OCT, as a valuable imaging technology, is capable of monitoring the clinical therapy procedure and assisting the calibration.