Showing papers on "Optical coherence tomography published in 2002"
TL;DR: Objective OCT criteria are highly sensitive and specific for characterizing different types of atherosclerotic plaques in vitro and will provide a basis for the interpretation of intracoronary OCT images obtained from patients.
Abstract: Background— High-resolution visualization of atherosclerotic plaque morphology may be essential for identifying coronary plaques that cause acute coronary events. Optical coherence tomography (OCT) is an intravascular imaging modality capable of providing cross-sectional images of tissue with a resolution of 10 μm. To date, OCT imaging has not been investigated in sufficient detail to assess its accuracy for characterizing atherosclerotic plaques. The aim of this study was to establish objective OCT image criteria for atherosclerotic plaque characterization in vitro. Methods and Results— OCT images of 357 (diseased) atherosclerotic arterial segments obtained at autopsy were correlated with histology. OCT image criteria for 3 types of plaque were formulated by analysis of a subset (n=50) of arterial segments. OCT images of fibrous plaques were characterized by homogeneous, signal-rich regions; fibrocalcific plaques by well-delineated, signal-poor regions with sharp borders; and lipid-rich plaques by signal...
1,174 citations
TL;DR: This work has developed a microscopy technique that uses optical projection tomography (OPT) to produce high-resolution 3D images of both fluorescent and nonfluorescent biological specimens with a thickness of up to 15 millimeters.
Abstract: Current techniques for three-dimensional (3D) optical microscopy (deconvolution, confocal microscopy, and optical coherence tomography) generate 3D data by "optically sectioning" the specimen. This places severe constraints on the maximum thickness of a specimen that can be imaged. We have developed a microscopy technique that uses optical projection tomography (OPT) to produce high-resolution 3D images of both fluorescent and nonfluorescent biological specimens with a thickness of up to 15 millimeters. OPT microscopy allows the rapid mapping of the tissue distribution of RNA and protein expression in intact embryos or organ systems and can therefore be instrumental in studies of developmental biology or gene function.
1,152 citations
TL;DR: Comparison between OCT and histology demonstrated that lipid-rich plaques and fibrous plaques have distinct OCT characteristics, and intracoronary OCT appears to be feasible and safe.
1,094 citations
TL;DR: The method, experimental setup, data processing, and images are discussed and it is shown that this technique might be as powerful as other optical coherence tomography techniques in the ophthalmologic imaging field.
Abstract: We present what is to our knowledge the first in vivo tomograms of human retina obtained by Fourier domain optical coherence tomography. We would like to show that this technique might be as powerful as other optical coherence tomography techniques in the ophthalmologic imaging field. The method, experimental setup, data processing, and images are discussed.
1,067 citations
TL;DR: An original microscope for high-resolution optical coherence tomography applications based on a Linnik interference microscope with high-numerical-aperture objectives that allows tomography in scattering media such as biological tissues.
Abstract: We describe an original microscope for high-resolution optical coherence tomography applications. Our system is based on a Linnik interference microscope with high-numerical-aperture objectives. Lock-in detection of the interference signal is achieved in parallel on a CCD by use of a photoelastic birefringence modulator and full-field stroboscopic illumination with an infrared LED. Transverse cross-section (en-face, or XY) images can be obtained in real time with better than 1-microm axial (Z) resolution and 0.5-microm transverse (XY) resolution. A sensitivity of approximately 80 dB is reached at a 1-image/s acquisition rate, which allows tomography in scattering media such as biological tissues.
666 citations
TL;DR: Submicrometer-resolution OCT is demonstrated in vitro on human colorectal adenocarcinoma cells HT-29, a novel light source that has great potential for development of spectroscopic OCT because its spectrum covers the absorption bands of several biological chromophores.
Abstract: Optical coherence tomography (OCT) with unprecedented submicrometer axial resolution achieved by use of a photonic crystal fiber in combination with a compact sub-10-fs Ti:sapphire laser (Femtolasers Produktions) is demonstrated for what the authors believe is the first time The emission spectrum ranges from 550 to 950 nm (?c=725 nm , Pout=27 mW) , resulting in a free-space axial OCT resolution of ~075 ?m , corresponding to ~05 ?m in biological tissue Submicrometer-resolution OCT is demonstrated in vitro on human colorectal adenocarcinoma cells HT-29 This novel light source has great potential for development of spectroscopic OCT because its spectrum covers the absorption bands of several biological chromophores
596 citations
TL;DR: The theory and calculation of the Stokes vector of light reflected from turbid media is described, application of PS-OCT to contemporary biomedical imaging problems is given and effect of multiple scattering and speckle on the accuracy and noise of the computed Stokes parameters is discussed.
Abstract: Polarization sensitive optical coherence tomography (PS-OCT) provides depth resolved measurements of the polarization state of light reflected from turbid media such as tissue. The theory and calculation of the Stokes vector of light reflected from turbid media is described and application of PS-OCT to contemporary biomedical imaging problems is given. Measurement of the depth resolved Stokes parameters allows determination of the degree of polarization and optical axis orientation in turbid media that can be modeled as a linear retarder. Effect of multiple scattering and speckle on the accuracy and noise of the computed Stokes parameters is discussed. Future directions for development of PS-OCT instrumentation for biological and medical applications is given.
536 citations
TL;DR: By reconstruction of both amplitude and phase, a new implementation of complex spectral optical coherence tomography (OCT) in biomedical imaging is demonstrated, able to use the negative and positive optical path differences to get images of objects of considerable thickness.
Abstract: We demonstrate a new implementation of complex spectral optical coherence tomography (OCT) in biomedical imaging. By reconstruction of both amplitude and phase we are able to use the negative and positive optical path differences to get images of objects of considerable thickness. An accompanying reduction of coherent noise improves the quality of the images. The property of the complex spectral OCT that permits the measurement range to be increased and permits the simultaneous use of phase and amplitude in spectral systems was not described previously. To show the potential of this technique we measured an anterior chamber of a porcine eye in vitro.
533 citations
Patent•
05 Mar 2002
TL;DR: In this article, an optical coherence tomography (OCT) device was proposed, which irradiates a biological tissue with low coherence light, obtains a high resolution tomogram of the inside of the tissue by low-coherent interference with scattered light from the tissue, and is provided with an optical probe which includes an optical fiber having a flexible and thin insertion part for introducing the low coherent light.
Abstract: An Optical Coherence Tomography (OCT) device irradiates a biological tissue with low coherence light, obtains a high resolution tomogram of the inside of the tissue by low-coherent interference with scattered light from the tissue, and is provided with an optical probe which includes an optical fiber having a flexible and thin insertion part for introducing the low coherent light. When the optical probe is inserted into a blood vessel or a patient's body cavity, the OCT enables the doctor to observe a high resolution tomogram. In a optical probe, generally, a fluctuation of a birefringence occurs depending on a bend of the optical fiber, and this an interference contrast varies depending on the condition of the insertion. The OCT of the present invention is provided with polarization compensation means such as a Faraday rotator on the side of the light emission of the optical probe, so that the OCT can obtain the stabilized interference output regardless of the state of the bend.
453 citations
Book•
15 Apr 2002
TL;DR: In this paper, the authors introduce the physics of light-tissue interaction and the application of light scattering by biological objects in imaging and imaging of tissue and tissue-like phytoplasm.
Abstract: Part 1 Physics of Light-Tissue Interaction - Diagnostical Aspects: Introduction to Light Scattering by Biological Objects Optics of Blood Propagation of Pulses and Photon Density Waves in Turbid Media Coherence Phenomena and Statistical Properties of Multiply Scattered Light Tissue Phantoms. Part 2 Pulse and Frequency-Domain Techniques for Tissue Spectroscopy and Imaging: Time-Resolved Imaging in Diffusive Media Frequency-Domain Techniques for Tissue Spectroscopy and Imaging Monitoring of Brain Activity With Near-Infrared Spectroscopy Signal Quantification and Localization in Tissue Near-Infrared Spectroscopy Time-Resolved Detection of Optoacoustic Profiles for Measurement of Optical Energy Distribution in Tissues. Part 3 Scattering, Fluorescence, and Infrared Fourier Transform Spectroscopy of Tissues: Light Back Scattering Spectroscopy of Epithelial Tissues - Principles and Applications Reflectance and Fluorescence Spectroscopy of Human Skin in Vivo Infrared and Raman Spectroscopy of Human Skin in Vivo Fluorescence Technologies in Biomedical Diagnostics. Part 4 Coherent-Domain Methods for Biological Flows and Tissue Ultrastructure Monitoring: Speckle and Doppler Methods of Blood and Lymph Flow Monitoring Real-Time Imaging of Microstructure and Blood Flows Using Optical Coherence Tomography Speckle Technologies for Monitoring and Imaging of Tissues and Tissue-Like Phantoms Optical Assessment of Tissue Mechanics.
427 citations
07 Nov 2002
TL;DR: Optical coherence tomography (OCT) is an emerging biomedical imaging modality which can generate high-resolution, cross-sectional images of microstructure in biological systems as mentioned in this paper.
Abstract: Optical coherence tomography (OCT) is an emerging biomedical imaging modality which can generate high resolution, cross-sectional images of microstructure in biological systems. OCT is analogous to ultrasound B mode imaging, except that it uses light instead of sound. Because the velocity of light is extremely high, direct electronic detection is not possible and imaging is performed using low coherence interferometry. Echoes of light from the specimen or tissue are correlated or interfered with light that travels a known reference path length. OCT images are generated by measuring the echo time delay of optical backscattering in the tissue as a function of transverse position and the data can be displayed as a false color or grey scale image. The axial resolution is determined by the coherence length of the light source. Imaging resolutions of 1 to 15 /spl mu/m can be achieved.
TL;DR: This system, based on a Linnik-type interference microscope, illuminated by a white-light thermal lamp, has the highest resolution demonstrated to date for OCT imaging and realistic volume rendering of structures inside biological tissues is possible.
Abstract: We have built a high-resolution optical coherence tomography (OCT) system, based on a Linnik-type interference microscope, illuminated by a white-light thermal lamp. The extremely short coherence length of the illumination source and the large aperture of the objectives permit resolution close to 1 µm in three dimensions. A parallel detection scheme with a CCD camera provides cross-section x–y image acquisition without scanning at a rate of up to 50 Hz. To our knowledge, our system has the highest resolution demonstrated to date for OCT imaging. With identical resolution in three dimensions, realistic volume rendering of structures inside biological tissues is possible.
TL;DR: This work reports on the incorporation of an axicon lens into the sample arm of an interferometer to overcome the trade-off between lateral resolution and focusing depth when conventional optical elements are used.
Abstract: In optical coherence tomography, axial and lateral resolutions are determined by the source coherence length and the numerical aperture of the sampling lens, respectively. Whereas axial resolution can be improved by use of a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. We report on the incorporation of an axicon lens into the sample arm of an interferometer to overcome this limitation. Using an axicon lens with a top angle of 160 degrees , we maintained 10-microm or better lateral resolution over a focusing depth of at least 6 mm. In addition to having high lateral resolution, the focusing spot has an intensity that is approximately constant over a greater depth range than when a conventional lens is used.
TL;DR: A double-beam polarization-sensitive system based on optical coherence tomography was built to measure the Mueller matrix of scattering biological tissue with high spatial resolution and the polarization parameters of a porcine tendon were extracted by decomposition of the measured Mueller matrix.
Abstract: A double-beam polarization-sensitive system based on optical coherence tomography was built to measure the Mueller matrix of scattering biological tissue with high spatial resolution. The Jones matrix of a sample can be determined with a single scan and subsequently converted into an equivalent nondepolarizing Mueller matrix. As a result, the system can be used to measure the Mueller matrix of an unstable sample, such as soft tissue. The polarization parameters of a porcine tendon, including magnitude and orientation of birefringence and diattenuation, were extracted by decomposition of the measured Mueller matrix.
TL;DR: The OCT system successfully reveals the birefringent nature of human skin tissue through the measurement of the distribution of each element of the Müller matrix of a measured object from 16 OCT images.
Abstract: We have developed a spectral interferometric optical coherence tomography (OCT) system with polarization sensitivity that is able to measure a two-dimensional tomographic image by means of one-dimensional mechanical scanning. Our system, which has an axial resolution of 32 mum , calculates the distribution of each element of the Muller matrix of a measured object from 16 OCT images. The OCT system successfully reveals the birefringent nature of human skin tissue.
TL;DR: A methodology for quantitative image correction in OCT which includes procedures for correction of nonlinear axial scanning and non-telecentric scan patterns, as well as a novel approach for refraction correction in layered media based on Fermat's principle are described.
Abstract: We describe a methodology for quantitative image correction in OCT which includes procedures for correction of nonlinear axial scanning and non-telecentric scan patterns, as well as a novel approach for refraction correction in layered media based on Fermat’s principle. The residual spatial error obtained in layered media with a fan-beam hand-held probe was reduced from several hundred micrometers to near the diffraction and coherence-length limits.
TL;DR: This work built a fiber-based PS-OCT setup that produces quasi-real-time images of the human retina in vivo and preliminary measurements showed that the double-pass phase retardation per unit depth of the RNFL near the optic nerve head is 39±6°/100 µm.
Abstract: To our knowledge, this is the first demonstration of in vivo depth-resolved birefringence measurements of the human retinal nerve fiber layer (RNFL) by use of polarization-sensitive optical coherence tomography (PS-OCT). Because glaucoma causes nerve fiber layer damage, which may cause loss of retinal birefringence, PS-OCT is a potentially useful technique for the early detection of glaucoma. We built a fiber-based PS-OCT setup that produces quasi-real-time images of the human retina in vivo. Preliminary measurements of a healthy volunteer showed that the double-pass phase retardation per unit depth of the RNFL near the optic nerve head is 39±6°/100 µm.
TL;DR: Retinal thickening correlated with fluorescein leakage in the angiograms to some extent, and there was an intermediate correlation between retinal thickness and visual acuity, particularly in patients without macular ischemia.
Abstract: BACKGROUND AND OBJECTIVE The authors conducted a controlled study to quantify macular retinal thickness in diabetic retinopathy using optical coherence tomography (OCT) as an objective and noninvasive tool. The relationship between retinal thickness and standard methods of evaluating macular edema was investigated. PATIENTS AND METHODS A total of 136 patients in different stages of diabetic retinopathy were examined with OCT. In addition, fluorescein angiograms as well as standard eye examinations were conducted. The control group consisted of 30 individuals with a normal macula. RESULTS In the controls, retinal thickness was 153 +/- 15 microm in the fovea, 249 +/- 19 microm in the temporal parafoveal region, and 268 +/- 20 microm in the nasal parafoveal region. In diabetic patients, retinal thickness was increased to 307 +/- 136 microm in the fovea, 337 +/- 88 microm in the temporal retina, and 353 +/- 95 microm in the nasal retina, respectively. The differences between diabetics and controls were highly significant (P < 0.001). Retinal thickening correlated with fluorescein leakage in the angiograms to some extent. There was an intermediate correlation between retinal thickness and visual acuity, particularly in patients without macular ischemia. Sensitivity of detecting clinically significant macular edema by measuring foveal retinal thickness was 89% and specificity was 96%. CONCLUSION Optical coherence tomography allows us to quantify retinal thickness in diabetic retinopathy with excellent reproducibility. OCT is able to detect sight-threatening macular edema with great reliability.
TL;DR: 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 is presented.
Abstract: 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. Images of onion cells demonstrate the improved image quality in a turbid biological sample. A quantitative analysis of the accompanying penalty in signal-to-noise ratio is given.
TL;DR: The experimental results show that this OCT system can be effectively applied to the measurement of soft tissues, which are less stable than hard tissues, and Polarization parameters such as diattenuation, birefringence, and orientation of the fast axis can be extracted through decomposition of the measured Jones matrix.
Abstract: Two-dimensional depth-resolved Jones-matrix images of scattering biological tissues were measured with novel double-source double-detector polarization-sensitive optical coherence tomography (OCT). The Jones matrix can be determined in a single scan with this OCT system. The experimental results show that this system can be effectively applied to the measurement of soft tissues, which are less stable than hard tissues. Polarization parameters such as diattenuation, birefringence, and orientation of the fast axis can be extracted through decomposition of the measured Jones matrix. The Jones matrix of thermally treated porcine tendon showed a reduction of birefringence from thermal damage. The Jones matrices of porcine skin and bovine cartilage also revealed that the density and orientation of the collagen fibers in porcine skin and bovine cartilage are not distributed as uniformly as in porcine tendon. Birefringence is sensitive to changes in tissue because it is based on phase contrast.
TL;DR: In this article, the authors proposed a quantum-optical coherence tomography (QOCT) for carrying out tomographic measurements with dispersion-cancelled resolution, which can also be used to extract the frequency-dependent refractive index of the medium.
Abstract: We propose a technique, called quantum-optical coherence tomography (QOCT), for carrying out tomographic measurements with dispersion-cancelled resolution. The technique can also be used to extract the frequency-dependent refractive index of the medium. QOCT makes use of a two-photon interferometer in which a swept delay permits a coincidence interferogram to be traced. The technique bears a resemblance to classical optical coherence tomography (OCT). However, it makes use of a nonclassical entangled twin-photon light source that permits measurements to be made at depths greater than those accessible via OCT, which suffers from the deleterious effects of sample dispersion. Aside from the dispersion cancellation, QOCT offers higher sensitivity than OCT as well as an enhancement of resolution by a factor of two for the same source bandwidth. QOCT and OCT are compared using an idealized sample.
Patent•
05 Aug 2002TL;DR: In this article, an optical coherence tomography (OCT) system including an interferometer provides illuminating light along a first optical path to a sample and an optical delay line and collects light from the sample along a second optical path remitted at several scattering angles to a detector.
Abstract: An optical coherence tomography (OCT) system including an interferometer provides illuminating light along a first optical path to a sample and an optical delay line and collects light from the sample along a second optical path remitted at several scattering angles to a detector. In one embodiment, illuminating light is directed along a number of incident light paths through a focusing lens to a sample. The light paths and focusing lens are related to the sample and to both the incident light source and the detector. In another embodiment, a focusing system directs light to a location in the sample. A transmission grating or acousto-optic modulator directs light from the sample at an angle representative of the wavelength of the incident light on the transmission grating or acousto-optic modulator.
TL;DR: In this paper, phase information derived from an in-phase and quadrature demodulator is used to estimate the mean blood flow velocity by the Kasai autocorrelation algorithm.
Patent•
05 Aug 2002
TL;DR: In this paper, a methodology for quantitative image correction in OCT images includes procedures for correction of non-telocentric scan patterns, as well as a novel approach for refraction correction in layered media based on Fermat's principle.
Abstract: Software techniques that are used for real-time imaging in OCT (Optical coherence tomography), particularly for correcting geometric and angular image distortions. In addition, a methodology for quantitative image correction in OCT images includes procedures for correction of non-telocentric scan patterns, as well as a novel approach for refraction correction in layered media based on Fermat's principle.
Patent•
30 Sep 2002
TL;DR: In this paper, a multiple-channel optical mapping apparatus is proposed to display both transversal and longitudinal images in an object, particularly the eye, which can operate on the same wavelength or on different wavelengths.
Abstract: The present invention relates to a multiple channel optical mapping apparatus which can deliver one or simultaneously at least two images of different depth resolutions or sequentially, images with different depth resolutions, or a combination of these images, or a single image with adjustable depth resolution. The multiple channels could be either multiple confocal channel and one or two optical coherence tomography channel, or two optical coherence tomography channels, or two confocal channels. The channels, either OCT or confocal can operate on the same wavelength or on different wavelengths. The apparatus can display both transversal as well as longitudinal images in an object, particularly the eye.
Journal Article•
TL;DR: Macular thickness changes are well correlated with changes in visual function and RNFL structure in glaucoma and may be a surrogate indicator of retinal ganglion cell loss.
Abstract: Objective To correlate macular thickness and retinal nerve fiber layer (RNFL) thickness in normal and glaucomatous eyes using optical coherence tomography. Methods Complete examination, automated achromatic perimetry, and optical coherence tomography of the peripapillary RNFL and macula were performed. Exclusion criteria were visual acuity of less than 20/40, diseases other than glaucoma, and unreliable automated achromatic perimetry. Macular thickness measurements were generated using 6 radial optical coherence tomographic scans (5.9 mm) centered on the fovea, and mean and quadrantic macular thickness values were calculated. Results Fifty-nine eyes of 59 patients (29 normal and 30 glaucomatous) were enrolled (mean ± SD age, 56.7 ± 20.3 years; range, 20-91 years). All eyes with glaucoma had associated visual field loss (mean ± SD mean defect, −8.4 ± 5.8 d B). Mean macular thickness was significantly associated with visual field mean defect ( R 2 = 0.47; P R 2 = 0.32; P R 2 = 0.38; P P = .005) than in the unaffected quadrant (286± 27 µm). Mean RNFL thickness in the affected quadrant (89 ± 53 µm) was significantly thinner ( P = .009) than in the unaffected quadrant (121 ± 39 µm). Main Outcome Measures Mean total and quadrantic macular and RNFL thickness measurements. Conclusions Macular thickness changes are well correlated with changes in visual function and RNFL structure in glaucoma and may be a surrogate indicator of retinal ganglion cell loss.
TL;DR: The results showed that optical clearing of blood by osmotic agents is potentially useful not only in blood sedimentation and aggregation studies but also in intravascular optical coherence tomography imaging techniques.
Abstract: The concept of refractive-index matching to enhance the optical
penetration depth of whole blood is discussed on the basis of in
vitro studies that used the technique of near-infrared optical
coherence tomography. It was found that optical clearing of blood
is defined not only by refractive-index matching but also by changes in
the size of red blood cells and in their aggregation ability when
chemicals are added. For example, in whole blood diluted to twice
its volume by saline with the addition of 6.5% glycerol, the total
attenuation coefficient was reduced from 4.2 to 2.0 mm-1,
and the optical penetration at 820 nm was correspondingly increased to
117%. For the other agents tested (glucose, dextrans, propylene
glycol, and trazograph) the enhancement of penetration was
20–150.5%. In the blood sedimentation study, regular or irregular
oscillations or jumps of the red-blood cell–plasma boundary were
observed. The 1-min time period of regular oscillations correlated
well with the kinetics of the aggregation process as described by the
two subsequent stages of formation of linear and three-dimensional
aggregates. The results also showed that optical clearing of blood
by osmotic agents is potentially useful not only in blood sedimentation
and aggregation studies but also in intravascular optical coherence
tomography imaging techniques.
TL;DR: A novel real-time phase-resolved functional optical coherence tomography system that uses optical Hilbert transformation that has high sensitivity and a larger dynamic range for measuring the Doppler frequency shift that is due to moving red blood cells.
Abstract: We have developed a novel real-time phase-resolved functional optical coherence tomography system that uses optical Hilbert transformation. When we use a resonant scanner in the reference arm of the interferometer, with an axial scanning speed of 4 kHz, the frame rate of both structural and Doppler blood-flow imaging with a size of 100 by 100 pixels is 10 Hz. The system has high sensitivity and a larger dynamic range for measuring the Doppler frequency shift that is due to moving red blood cells. Real-time images of in vivo blood flow in human skin obtained with this interferometer are presented.
TL;DR: The size distribution of refractive index structure variations in epithelial cells as well as in nuclei isolated from epithelium from measurements of the angular dependence of polarized light scattering demonstrates that not only are biological cells very heterogeneous, but so are the nuclei within them.
Abstract: An understanding of the relationship between tissue structures and light scattering from tissue will help facilitate the development and acceptance of noninvasive optical diagnostics including elastic scattering spectroscopy, diffuse reflectance, and optical coherence tomography. For example, a quantitative model of the structures that scatter light in epithelial cells would allow determination of what structures control the characteristics of in vivo light transport measurements and subsequently could provide a detailed relationship between cellular structures and optical measurements. We have determined the size distribution of refractive index structure variations in epithelial cells as well as in nuclei isolated from epithelial cells from measurements of the angular dependence of polarized light scattering. The quantitative size distributions we obtained for both whole cells and isolated nuclei include particles with effective radii of 2 µm to 10 nm or less and contain orders of magnitude more small particles than large particles. These results demonstrate that not only are biological cells very heterogeneous, but so are the nuclei within them. Light scattering is likely sensitive to structures smaller than those commonly investigated by standard pathology methods.
TL;DR: OCT is a powerful imaging modality which can provide new insight in assessing and understanding normal and abnormal cardiac development in a variety of animal models.
Abstract: Background— Optical coherence tomography (OCT) is a depth-resolved, noninvasive, non-destructive imaging modality, the use of which has yet to be fully realized in developmental biology. Methods and Results— We visualized embryonic chick hearts at looping stages using an OCT system with a 22 μm axial and 27 μm lateral resolution and an acquisition rate of 4000 A-scans per second. Normal chick embryos from stages 14 to 22 and sham-operated and cardiac neural crest-ablated embryos from stages 15 and 18 were scanned by OCT. Three-dimensional data sets were acquired and processed to create volumetric reconstructions and short video clips. The OCT-scanned embryos (2 in each group) were photographed after histological sectioning in comparable planes to those visualized by OCT. The optical and histological results showing cardiovascular microstructures such as myocardium, the cardiac jelly, and endocardium are presented. Conclusions— OCT is a powerful imaging modality which can provide new insight in assessing a...