Prospective grading of neoplastic change in rat esophagus. Chalut department of biomedical engineering, fitzpatrick institute for photonics, duke university, durham, nc, usa abstract. Prospective grading of neoplastic change in rat esophagus epithelium using angleresolved lowcoherence interferometry. Guidance of angleresolved low coherence interferometry. A modified michelson interferometer is used to measure pathlength resolved angular distributions of light backscattered by turbid media. The probe employs a scanning singlemode fiber to collect the angular scattering distribution of the sample, which is analyzed using the mie theory to obtain the average size of the scatterers. Rapid, depthresolved light scattering measurements using fourier.
Clinical angle resolved low coherence interferometry a lci alci is an optical technique that provides depth resolved nuclear morphology measurements by analyzing variations in. Let us now calculate the lci signal in this michelson interferometer. These measurements enable the determination of scatterer size via elastic scattering properties. Pdf we present a novel fourierdomain angleresolved lowcoherence interferometry a lci fiber probe designed for in vivo clinical application in. Angleresolved low coherence interferometry for detection. Abstractthe combination of lowcoherence interferometry with angleresolved light scattering measurements has been shown to be a powerful method for. Angleresolved lowcoherence interferometry alci is an emerging biomedical imaging technology which uses the properties of scattered light to measure the.
In situ assessment of intraepithelial neoplasia in hamster. Rapid angleresolved lowcoherence interferometry measurements. A scattering phantom for observing long range order with twodimensional angleresolved lowcoherence interferometry sk yarmoska, s kim, te matthews, a wax biomedical optics express 4 9, 17421748, 20. Guidance of angleresolved low coherence interferometry using colocated optical coherence tomography on rat esophageal tissue.
Nuclear morphology measurements with angleresolved low. Techniques such as optical coherence tomography oct 123 and angleresolved lowcoherence interferometry alci 4 56 rely on the precise delivery and collection of singlemode. Angleresolved lowcoherence interferometry wikipedia. Angleresolved lowcoherence interferometry alci is an optical biopsy technique that measures scattered light from tissue to determine nuclear size with. Angleresolved low coherence interferometry as mentioned above, alci is a light scattering technique that combines light scattering spectroscopy with the depthsectioning capability of oct. Detection of intestinal dysplasia using angleresolved low. Giacomelli department of biomedical engineering duke university. Because alci is implemented using a lowcoherence source, it enables light. Various correlations have been found between the state of tissue health and the measurements of subcellular objects. This allows interferometry depth measurements to be combined with density measurements. The third portion of this work develops the use of angleresolved interferometry for imaging through highly scattering media by exploiting the tendency of scatterers to forward scatter light. Light scattering measurements of subcellular structure. Review and recent development of angleresolved low. The strength of alci is its depth resolution, enabling detection of increased nuclear diameter at subsurface layers of the epithelium and yielding high.
Angleresolved low coherence interferometry alci is an optical biopsy technique that allows for depthresolved, labelfree measurement of the average size and optical density of cell nuclei in epithelial tissue to assess the tissue health. Barretts esophagus be is a metaplastic change of the esophagus which is associated with an increased risk of esophageal adenocarcinoma eac. Angleresolved low coherence interferometry alci is a noninvasive method of assessing neoplastic tissue. Measurement of angular distributions by use of low. Detection of dysplasia in barretts esophagus with in vivo depthresolved nuclear morphology measurements. Angular light scattering studies using lowcoherence interferometry. Scanning fiber angleresolved low coherence interferometry. We present a light scattering study using angleresolved low coherence interferometry alci to assess nuclear morphology and subcellular structure within mcf7 cells at several time points after treatment with chemotherapeutic agents. Diagnostic imaging and assessment using angle resolved low. Design and validation of an angleresolved lowcoherence. Clinical use of scanning angleresolved low coherence interferometry for detection of cervical dysplasia w kendall, d ho, k chu, m zinaman, d wieland, a.
Angleresolved lowcoherence interferometry alci, a novel light scattering technique, was developed to quantify nuclear morphology for early cancer detection. We present a quantitative study of the nuclear morphometry of epithelial cells in an animal model of esophageal carcinogenesis. Oct is an amplitude technique, which uses the narrow temporal crosscorrelation function between the sample and reference fields to achieve axial section. Pdf design and validation of an angleresolved lowcoherence.
Angleresolved lowcoherence interferometry alci is another noninvasive optical spectroscopic technique which, like laser induced autofluorescence and oct, can be used to perform an optical biopsy of intact, living tissue 96, 97. Lowcoherence interferometry lci has been explored as an alternative for detecting singly scattered light from subsurface sites for lss. Clinical use of scanning angleresolved low coherence. Initial experiments with a broadband light source and its second harmonic showed that elasticscattering information could be recovered with lci. This novel technique evaluates nuclear size with the depth resolution making it particularly powerful.
Fourierdomain lowcoherence interferometry for light. Wavelengthdependent scattering in spectroscopic optical. Clinical angle resolved low coherence interferometry a. These measurements enable the determination of scatterer size. Intact ex vivo tissue samples were scanned using the heterodyne alci technique 9, 10. Angleresolved lowcoherence interferometry alci is an optical biopsy technique that measures scattered light from tissue to determine nuclear size with submicronlevel accuracy. In this study, alci is used for the first time to noninvasively measure small changes in nuclear morphology in response to environmental stimuli. Diagnostic imaging and assessment using angle resolved low coherence interferometry. Although the nuclear diameter and eccentricity are not observed to change, the light scattering signal reveals a change in the organization of subcellular. The third portion of this work develops the use of angleresolved interferometry for imaging through highly scattering media by exploiting the tendency of scatterers to.
This approach can noninvasively probe the structure of an arbitrary cell sample. Presentation mode open print download current view. In situ detection of neoplastic transformation and. The alci technique uses coherence gating, made possible by the use of a lowcoherence source coherence. Angleresolved lowcoherence interferometry alci is used to obtain quantitative, depthresolved nuclear morphology measurements. This new technique probes cellular structure by measuring scattered light, as in flow cytometry, but offers an advantage in that the structure can be examined in situ, avoiding the need to disrupt the cell monolayer. Angleresolved lowcoherence interferometry alci uses scattered light to measure the sizes of subcellular objects, including cell nuclei. This new technique probes cellular structure by measuring scattered light, as in flow cytometry, but offers an advantage in that the structure can be examined in situ, avoiding the need to disrupt the. Cellular organization and substructure measured using. The alci probe can be deployed through the accessory channel of a standard endoscope and provides feedback to physicians to guide physical biopsies. Inverse scattering solutions using lowcoherence light.
Development of angleresolved low coherence interferometry. This dispersion effect ultimately degrades the axial resolution of oct images, as we will see in the next section. We have developed a novel angleresolved low coherence interferometry scheme for rapid measurement of depthresolved angular scattering distributions. Angleresolved lowcoherence interferometry a lci offers another means of optical biopsy. We present a novel angleresolved low coherence interferometry scheme for rapid measurement of depthresolved angular scattering. In situ detection of nuclear atypia in barretts esophagus. We compare the average diameter and texture of cell nuclei in rat esophagus epithelial tissue to grading criteria established in a previous alci study to prospectively grade neoplastic progression. Abstract we measure the organization and substructure of ht29 epithelial cells in a monolayer using angleresolved lowcoherence interferometry. Fourier domain angleresolved low coherence interferometry falci system and method that enables data acquisition of angleresolved and depthresolved spectra information of a sample, in which depth and size information about the sample can be obtained with a single scan at rapid rates for in vivo applications in particular. Detection of intestinal dysplasia using angleresolved low coherence interferometry.
Oct, which is essentially spatially resolved lowcoherence interferometry lci, was first demonstrated in 1991 as a labelfree 3d imaging method for deeptissue imaging 12. Feasibility of clinical detection of cervical dysplasia. The study of intact, living cells using noninvasive optical spectroscopic methods offers the. We measure the organization and substructure of ht29 epithelial cells in a monolayer using angleresolved lowcoherence interferometry. Frequencydomain angle resolved lowcoherence interferometry falci is an optical spectroscopic technique applied through an endoscopic fiber bundle and measures the depthresolved nuclear morphology of tissue, a key biomarker for identifying dysplasia. We demonstrate the first clinical implementation of a scanning method to perform angleresolved lowcoherence interferometry alci to detect cervical dysplasia over a large area without repositioning. In the first applications, the approach used a timedomain interferometry scheme and was validated using animal models of carcinogenesis to assess the feasibility of detecting dysplasia in situ. We present a fiberoptic probe for fourierdomain angleresolved low coherence interferometry for the determination of depthresolved scatterer size. Shaheen, c and adam wax d a duke university, department of biomedical engineering, 6 hudson hall, durham, north carolina 27708.
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