Optical coherence tomography

About: Optical coherence tomography is a research topic. Over the lifetime, 19051 publications have been published within this topic receiving 477433 citations. The topic is also known as: optical coherent tomography.

Mueller matrix imaging of human colon tissue for cancer diagnostics: how Monte Carlo modeling can help in the interpretation of experimental data.

Abstract: Colon samples with both healthy and cancerous regions have been imaged in diffuse light and backscattering geometry by using a Mueller imaging polarimeter. The tumoral parts at the early stage of cancer are found to be less depolarizing than the healthy ones. This trend clearly shows that polarimetric imaging may provide useful contrasts for optical biopsy. Moreover, both types of tissues are less depolarizing when the incident polarization is linear rather than circular. However, to really optimize an optical biopsy technique based on polarimetric imaging a realistic model is needed for polarized light scattering by tissues. Our approach to this goal is based on numerical Monte-Carlo simulations of polarized light propagation in biological tissues modeled as suspensions of monodisperse spherical scatterers representing the cell nuclei. The numerical simulations were validated by comparison with measurements on aqueous polystyrene sphere suspensions, which are commonly used as tissue phantoms. Such systems exhibit lower depolarization for incident linear polarization in the Rayleigh scattering regime, i.e. when the sphere diameters are smaller than the wavelength, which is obviously not the case for cell nuclei. In contrast, our results show that this behaviour can also be seen for “large” scatterers provided the optical index contrast between the spheres and the surrounding medium is small enough, as it is likely to be the case in biological tissues.

Diagnosis of vitreoretinal adhesions in macular disease with optical coherence tomography.

Abstract: Purpose To compare the relative incidence of vitreoretinal adhesions associated with partial vitreous separation within the macula diagnosed with optical coherence tomography (OCT) with that of those diagnosed with biomicroscopy. Methods The authors obtained linear cross-sectional retinal images using OCT in patients with selected macular diseases. Additional studies included biomicroscopy, fundus photography, fluorescein angiography, and B-scan ultrasonography. Results Optical coherence tomography was performed on 132 eyes of 119 patients. Vitreoretinal adhesions within the macula were identified using OCT in 39 eyes (30%) with the following diagnoses: idiopathic epiretinal membrane (n = 13), diabetic retinopathy (n = 7), idiopathic macular hole (n = 7), cystoid macular edema (n = 7), and vitreomacular traction syndrome (n = 5). Biomicroscopy identified vitreoretinal adhesions in only 11 eyes (8%). Two distinct vitreoretinal adhesion patterns were identified with OCT, each associated with partial separation of the posterior hyaloid face: focal (n = 25) and multifocal (n = 14). Conclusions Optical coherence tomography is more sensitive than biomicroscopy in identifying vitreoretinal adhesions associated with macular disease.

Three-dimensional cellular-level imaging using full-field optical coherence tomography.

Abstract: An ultrahigh-resolution full-field optical coherence tomography (OCT) system has been developed for cellular-level imaging of biological media. The system is based on a Linnik interference microscope illuminated with a tungsten halogen lamp, associated with a high-resolution CCD camera. En face tomographic images are produced in real time, with the best spatial resolution ever achieved in OCT (0.7 µm × 0.9 µm, axial × transverse). A shot-noise limited detection sensitivity of 80 dB can be reached with an acquisition time per image of 1 s. Images of animal ophthalmic biopsies and vegetal tissues are shown.

Imaging Congenital Optic Disc Pits and Associated Maculopathy Using Optical Coherence Tomography

Abstract: Objective: To elucidate the anatomy of congenital optic disc pits with and without maculopathy using optical coherence tomography. Setting: All patients were examined, photographed, and scanned at the New York Eye and Ear Infirmary. Patients: Ten eyes of eight consecutive patients with congenital optic disc pits were studied. Three eyes had associated serous macular detachment (group 1), four had evidence of resolved detachment (group 2), and three had no clinical macular pathologic lesion (group 3). Methods: Optical coherence tomography, a new, noninvasive, noncontact, imaging technology capable of producing cross-sectional images of the retina in vivo with high resolution ( Results: Communication between a schisis cavity or subretinal space and the optic nerve pit was imaged in all eyes in group 1. No such communication could be identified in groups 2 and 3. Cystic degeneration and schisis were imaged in the peripapillary retina, macula, or both in all eyes of groups 1 and 2 and in one patient in group 3. A direct communication between the subretinal space and vitreous cavity could not be identified in any eye. Conclusions: Schisis formation plays an integral role in the development of serous retinal detachment in the presence of congenital optic disc pits. Our findings are consistent with the theory that the optic disc pit acts as a conduit for fluid flow between the schisis cavity or subretinal space and the subarachnoid space.

An optical coherence microscope for 3-dimensional imaging in developmental biology

Abstract: An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument.