Search results for "Optical Coherence"
showing 10 items of 223 documents
Chromoendoscopy and Other Novel Imaging Techniques
2006
The newly developed high-resolution and magnification endoscopes offer features that allow more and new mucosal details to be seen. They are commonly used in conjunction with chromoendoscopy. The analysis of mucosal surface details is beginning to resemble histologic examination. More accurate recognition of small flat and depressed neoplastic lesions is possible. Endoscopic prediction of neoplastic and nonneoplastic tissue is possible by analysis of surface architecture of the mucosa, which influences the endoscopic management. For the diagnosis of flat adenomas, chromoendoscopy should be a part of the endoscopist's armamentarium. In inflammatory bowel disease, chromoendoscopy can be used …
In vivo optical coherence tomography imaging in a case of mucous membrane pemphigoid and a negative Nikolsky's sign.
2017
There is currently a growing interest in new diagnostic tools of the oral cavity and mucosa which are non-invasive, repeatable and reliable. A diagnosis of a suspected, autoimmune pathology was made regarding a 57-year-old patient with desquamative gingivitis. However, a negative Nikolsky's sign did not seem to indicate a diagnosis of mucous membrane pemphigoid neither was there any indication as to the optimum location for an incisional biopsy. As an imaging method, the use of optical coherence tomography (OCT) has enabled the obtaining of tomographic (cross-sectional) scans of tissue. Such images are acquired prior to and after verifying Nikolsky's sign, thereby enabling the clinician to …
Optical coherence tomography and Raman spectroscopy for ex vivo characterization of canine skin and subcutaneous tumors: preliminary results
2021
Cancer is one of the leading causes of companion animal mortality. Up to 30% of all canine and feline tumors appear on or directly under the skin. To date, only a limited number of studies applied biophotonics techniques for optical characterization and detection of tumors in pets. In this work, we acquired ex vivo optical coherence tomography (OCT) images and Raman spectra of native skin and the most common canine and feline skin and subcutaneous tumors; lipomas, mast cell tumors, and soft tissues sarcomas. Lipomas exhibited the most distinctive tissue morphology (i.e., honeycomb structure) and biochemistry (lipid-related Raman peaks of 1063, 1301, and 1652 cm-1). Moreover, lipomas had sig…
Evaluation of Skin Vascular Malformations’ Laser Treatment by RGB and Multi-spectral Imaging
2012
RGB imaging system for mapping and monitoring of hemoglobin changes in skin has been tested for evaluation of vascular malformations’ laser treatment. The multi-spectral imaging system was used as the reference.
Subtle retinal pathology in amyotrophic lateral sclerosis
2014
Amyotrophic lateral sclerosis (ALS) is characterized by neuro-ophthalmological abnormalities beyond disturbed oculomotor control such as decreased visual acuity and disturbed visual evoked potentials. Here we report retinal alterations in a cohort of 24 patients with clinically definite (n = 20) or probable (n = 4) ALS as compared to matched controls. High-resolution spectral domain optical coherence tomography with retinal segmentation revealed a subtle reduction in the macular thickness and the retinal nerve fiber layer (RNFL) as well as a marked thinning of the inner nuclear layer (INL). Our data indicate an unprecedented retinal damage pattern and suggest neurodegeneration beyond the mo…
Diagnostic Concordance between Optical Coherence Tomography and Histological Investigations for Immune-Mediated Desquamative Gingivitis: Observationa…
2021
Desquamative gingivitis (DG) denotes a heterogeneous immune-mediated disease for which early diagnosis represents a great challenge. The main aim of this study is to validate diagnostic concordance between specific Optical Coherence Tomography (OTC) patterns for DG related to oral Lichen Planus (OLP), Pemphigus Vulgaris (PV), and Mucous Membrane Pemphigoid (MMP) and definitive histological diagnosis. Forty-three patients with suspected immune-mediated DGs, were progressively recruited. Before biopsy, an OCT preliminary evaluation was performed using specific pre-determined OCT diagnostic patterns (i.e., morphology and localization of blisters, status of the basal membrane, epithelial thickn…
Clinical use of intracoronary imaging. Part 1: guidance and optimization of coronary interventions. An expert consensus document of the European Asso…
2018
This Consensus Document is the first of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The first document appraises the role of intracoronary imaging to guide percutaneous coronary interventions (PCIs) in clinical practice. Current evidence regarding the impact of intracoronary imaging guidance on cardiovascular outcomes is summarized, and patients or lesions most likely to derive clinical benefit from an imaging-guided intervention are identified. The relevance of the u…
Resolution-enhanced optical coherence tomography based on classical intensity interferometry.
2009
We propose a fourth-order interference scheme for optical coherence tomography operating with broadband incoherent (or quasi-incoherent) light. It is shown that using this proposal, an axial resolution improvement by a factor of 2 and a better sensitivity for weakly reflecting samples are obtained than with the standard second-order correlation scheme. From a practical perspective, we suggest the use of broadband Q-switched pulses and performing ultrafast intensity correlation with a nonlinear crystal. The global performance of our proposal is illustrated by means of numerical simulations
Space-Time Analogies in Optics
2011
Abstract The so-called space-time analogy constitutes a source of inspiration to understand, engineer, and implement new systems for ultrafast optical signal processing based on concepts borrowed from the well-established field of Fourier Optics. In this review, we start by describing in a comprehensive manner the most basic notions of this analogy and discuss some recent developments with state-of-the-art technology, including the silicon-chip-based time lens and ultra-dispersive Raman devices, among others. Apart from the applications in optical communications, special emphasis is paid on the collateral benefits that the “ultra” appellative brings in fields as diverse as optical frequency…
‘Nonlocal’ dispersion cancelation with classical light
2009
We show a classical analog of the original nonlocal dispersion cancelation effect in intensity interferometry with stationary light obeying Gaussian statistics. The dispersion compensation is due to the uncorrelation of the spectral components of the radiation. Although this classical counterpart phenomenon is not nonlocal in a strict quantum mechanical sense, it suggests that some second-order interference devices relying on temporal entanglement do not require a quantum light source.