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ABSTRACT: We evaluated the feasibility of using optical coherence tomography and optical coherence microscopy technology to assess human kidney morphology.
A total of 35 renal specimens from 19 patients, consisting of 12 normal tissues and 23 tumors (16 clear cell renal cell carcinomas, 5 papillary renal cell carcinomas and 2 oncocytomas) were imaged ex vivo after surgical resection. Optical coherence tomography and optical coherence microscopy images were compared to corresponding hematoxylin and eosin histology to identify characteristic features of normal and pathological renal tissues. Three pathologists blinded to histology evaluated the sensitivity and specificity of optical coherence microscopy images to differentiate normal from neoplastic renal tissues.
Optical coherence tomography and optical coherence microscopy images of normal kidney revealed architectural features, including glomeruli, convoluted tubules, collecting tubules and loops of Henle. Each method of imaging renal tumors clearly demonstrated morphological changes and decreased imaging depth. Optical coherence tomography and microscopy features matched well with the corresponding histology. Three observers achieved 88%, 100% and 100% sensitivity, and 100%, 88% and 100% specificity, respectively, when evaluating normal vs neoplastic specimens using optical coherence microscopy images with substantial interobserver agreement (κ = 0.82, p <0.01).
Integrated optical coherence tomography and optical coherence microscopy imaging provides coregistered, multiscale images of renal pathology in real time without exogenous contrast medium or histological processing. High sensitivity and specificity were achieved using optical coherence microscopy to differentiate normal from neoplastic renal tissues, suggesting possible applications for guiding renal mass biopsy or evaluating surgical margins.
The Journal of urology 12/2011; 187(2):691-9. · 4.02 Impact Factor
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ABSTRACT: Three-dimensional (3D) tissue imaging methods are expected to improve surgical management of cancer. In this study, we examined the feasibility of two 3D imaging technologies, optical coherence tomography (OCT) and optical coherence microscopy (OCM), to view human breast specimens based on intrinsic optical contrast. Specifically, we imaged 44 ex vivo breast specimens including 34 benign and 10 malignant lesions with an integrated OCT and OCM system developed in our laboratory. The system enabled 4-μm axial resolution (OCT and OCM) with 14-μm (OCT) and 2-μm (OCM) transverse resolutions, respectively. OCT and OCM images were compared with corresponding histologic sections to identify characteristic features from benign and malignant breast lesions at multiple resolution scales. OCT and OCM provide complimentary information about tissue microstructure, thus showing distinctive patterns for adipose tissue, fibrous stroma, breast lobules and ducts, cysts and microcysts, as well as in situ and invasive carcinomas. The 3D imaging capability of OCT and OCM provided complementary information to individual 2D images, thereby allowing tracking features from different levels to identify low-contrast structures that were difficult to appreciate from single images alone. Our results lay the foundation for future in vivo optical evaluation of breast tissues, using OCT and OCM, which has the potential to guide core needle biopsies, assess surgical margins, and evaluate nodal involvement in breast cancer.
Cancer Research 11/2010; 70(24):10071-9. · 7.86 Impact Factor
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ABSTRACT: Optical coherence microscopy (OCM) is a promising technique for high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging was developed at 1060 nm wavelength at frame rates up to 5 Hz with resolutions of < 4 microm axial and < 2 microm transverse. The system utilized a novel polarization compensation method to combat wavelength dependent source polarization and achieve broadband electro-optic phase modulation compatible with ultrahigh axial resolution. In addition, the system incorporated an auto-focusing feature that enables precise, near real-time alignment of the confocal and coherence gates in tissue, allowing user-friendly optimization of image quality during the imaging procedure. Ex vivo cellular images of human esophagus, colon, and cervix as well as in vivo results from human skin are presented. Finally, the system design is demonstrated with a miniaturized piezoelectric fiber-scanning probe which can be adapted for laparoscopic and endoscopic imaging applications.
Optics Express 03/2010; 18(5):4222-39. · 3.59 Impact Factor
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Article:
BiOS
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ABSTRACT: We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. Thirty four thyroid gland specimens were imaged from 17 patients, covering a spectrum of pathology, ranging from normal thyroid to neoplasia and benign disease. The integrated OCT and OCM imaging system allows seamlessly switching between low and high magnifications, in a way similar to traditional microscopy. Good correspondence was observed between optical images and histological sections. The results provide a basis for interpretation of future OCT and OCM images of the thyroid tissues and suggest the possibility of future in vivo evaluation of thyroid pathology.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
02/2010;
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ABSTRACT: Optical intrinsic signal imaging (OISI) provides two-dimensional, depth-integrated activation maps of brain activity. Optical coherence tomography (OCT) provides depth-resolved, cross-sectional images of functional brain activation. Co-registered OCT and OISI imaging was performed simultaneously on the rat somatosensory cortex through a thinned skull during forepaw electrical stimulation. Fractional signal change measurements made by OCT revealed a functional signal that correlates well with that of the intrinsic hemodynamic signals and provides depth-resolved, layer-specific dynamics in the functional activation patterns indicating retrograde vessel dilation. OCT is a promising a new technology which provides complementary information to OISI for functional neuroimaging.
Journal of Neuroscience Methods 01/2009; 178(1):162-73. · 1.98 Impact Factor
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ABSTRACT: Optical coherence tomography (OCT) is an emerging medical imaging technology which generates high resolution, cross-sectional images in situ, without the need for excisional biopsy. Previous clinical studies using endoscopic OCT with standard 10-15 microm axial resolution have demonstrated its capability in diagnosing Barrett's esophagus (BE) and high-grade dysplasia (HGD). Quantitative OCT image analysis has shown promise for detecting HGD in Barrett's esophagus patients. We recently developed an endoscopic OCT system with an improved axial resolution of approximately 5 microm. The goal in this manuscript is to compare standard resolution OCT and ultrahigh resolution OCT (UHR-OCT) for image quality and computer-aided detection using normal and Barrett's esophagus. OCT images of gastrointestinal (GI) tissues were obtained using UHR-OCT (5.5 microm) and standard resolution OCT (13 microm). Image quality including the speckle size and sharpness was compared. Texture features of endoscopic OCT images from normal and Barrett's esophagus were extracted using quantitative metrics including spatial frequency analysis and statistical texture analysis. These features were analyzed using principal component analysis (PCA) to reduce the vector dimension and increase the discriminative power, followed by linear discrimination analysis (LDA). UHR-OCT images of GI tissues improved visualization of fine architectural features compared to standard resolution OCT. In addition, the quantitative image feature analysis showed enhanced discrimination of normal and Barrett's esophagus with UHR-OCT. The ability of UHR-OCT to resolve tissue morphology at improved resolution enables visualization of subtle features in OCT images, which may be useful in disease diagnosis. Enhanced classification of image features using UHR-OCT promises to help in the computer-aided diagnosis of GI diseases.
Optics Express 03/2008; 16(4):2469-85. · 3.59 Impact Factor
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ABSTRACT: Institutional review board approval at the participating institutions was obtained. Informed consent was waived for this HIPAA-compliant study. The study purpose was to establish the correspondence of optical coherence tomographic (OCT) image findings with histopathologic findings to understand which features characteristic of breast lesions can be visualized with OCT. Imaging was performed in 119 specimens from 35 women aged 29-81 years with 3.5-microm axial resolution and 6-microm transverse resolution at 1.1-microm wavelength on freshly excised specimens of human breast tissue. Three-dimensional imaging was performed in 43 specimens from 23 patients. Microstructure of normal breast parenchyma, including glands, lobules, and lactiferous ducts, and stromal changes associated with infiltrating cancer were visible. Fibrocystic changes and benign fibroadenomas were identified. Imaging of ductal carcinoma in situ, infiltrating cancer, and microcalcifications correlated with corresponding histopathologic findings. OCT is potentially useful for visualization of breast lesions at a resolution greater than that of currently available clinical imaging methods.
Radiology 10/2007; 244(3):865-74. · 5.73 Impact Factor
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ABSTRACT: An optical coherence microscopy system based on line illumination and detection is demonstrated. The system uses a Linnik-type interferometer illuminated by a broadband Ti:sapphire laser and detected by a high-speed, line-scan CCD camera. This approach is less sensitive to incoherent scattering and sample motion than full-field imaging. Spatial resolutions of approximately 2 microm x approximately 3 microm(transverse x axial) are achieved. The sensitivity of the system is 93 dB with averaging over 30 line scans. En face real time, cellular-level imaging of biological tissues is demonstrated at approximately 2 frames/s.
Optics Letters 08/2007; 32(14):1971-3. · 3.40 Impact Factor
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ABSTRACT: Swept source optical coherence microscopy (OCM) enables cellular resolution en face imaging as well as integration with optical coherence tomography (OCT) cross sectional imaging. A buffered Fourier domain mode-locked (FDML) laser light source provides high speed, three dimensional imaging. Image resolutions of 1.6 microm x 8 microm (transverse x axial) with a 220 microm x 220 microm field of view and sensitivity higher than 98 dB are achieved. Three dimensional cellular imaging is demonstrated in vivo in the Xenopus laevis tadpole and ex vivo in the rat kidney and human colon.
Optics Express 06/2007; 15(10):6210-7. · 3.59 Impact Factor
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ABSTRACT: Ultrahigh resolution two and three-dimensional optical coherence tomography (OCT) imaging was performed using a miniaturized, two-axis scanning catheter based upon microelectromechanical systems (MEMS) mirror technology. The catheter incorporated a custom-designed and fabricated, 1-mm diameter MEMS mirror driven by angular vertical comb (AVC) actuators on both an inner mirror axis and an outer, orthogonal gimbal axis. Using a differential drive scheme, a linearized position response over +/- 6 degrees mechanical angle was achieved. The flexible, fiber-optic catheter device measured < 5 mm in outer diameter with a rigid length of ~ 2.5 cm at the distal end. In vivo and ex vivo images are presented with < 4 microm axial and ~ 12 microm transverse resolution in tissue.
Optics Express 04/2007; 15(5):2445-53. · 3.59 Impact Factor
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Pei-Lin Hsiung,
Liron Pantanowitz, Aaron D Aguirre,
Yu Chen,
Darshan Phatak,
Tony H Ko,
Stephane Bourquin,
Stuart J Schnitt,
Sugrah Raza,
James L Connolly,
Hiroshi Mashimo,
James G Fujimoto
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ABSTRACT: Ultrahigh-resolution optical coherence tomography (OCT) has an axial resolution of <5 microm, 2 to 3 times finer than standard OCT. This study investigates ultrahigh-resolution and three-dimensional OCT for ex vivo imaging of the large and small intestines and correlates images with histology.
Ultrahigh-resolution OCT imaging was performed on fresh surgical specimens from the large and small intestines in the pathology laboratory, and images were correlated with histology. OCT was performed at 1.3-microm wavelength with 4.5-microm axial x 11-microm transverse resolution and at 1.1-microm wavelength with 3.5-microm axial x 6-microm transverse resolution. Three-dimensional OCT also was investigated.
Normal and pathologic areas from 23 surgical specimens of the large and small intestines were imaged. Ultrahigh-resolution OCT distinguished the epithelial layer of the mucosa and visualized individual villi, glands, and crypts. Finer transverse resolutions improved visualization of features, e.g., the epithelium, but reduced the depth of field. Architectural distortion of glands from inflammatory and neoplastic processes was observed. Three-dimensional rendering enabled visualization of surface pit pattern and mucosal folds as well as subsurface crypt microstructure.
This study evaluates new OCT technology and can provide a baseline for interpreting future ultrahigh-resolution endoscopic OCT studies.
Gastrointestinal Endoscopy 10/2005; 62(4):561-74. · 4.88 Impact Factor
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ABSTRACT: Optical coherence tomography (OCT) is an emerging medical imaging technology that enables high-resolution, noninvasive, cross-sectional imaging of microstructure in biological tissues in situ and in real time. When combined with small-diameter catheters or needle probes, OCT offers a practical tool for the minimally invasive imaging of living tissue morphology. We evaluate the ability of OCT to image normal kidneys and discriminate pathological changes in kidney structure. Both control and experimental preserved rat kidneys were examined ex vivo by using a high-resolution OCT imaging system equipped with a laser light source at 1.3-microm wavelength. This system has a resolution of 3.3 microm (depth) by 6 microm (transverse). OCT imaging produced cross-sectional and en face images that revealed the sizes and shapes of the uriniferous tubules and renal corpuscles. OCT data revealed significant changes in the uriniferous tubules of kidneys preserved following an ischemic or toxic (i.e., mercuric chloride) insult. OCT data was also rendered to produce informative three-dimensional (3-D) images of uriniferous tubules and renal corpuscles. The foregoing observations suggest that OCT can be a useful non-excisional, real-time modality for imaging pathological changes in donor kidney morphology prior to transplantation.
Journal of Biomedical Optics 12(3):034008. · 3.16 Impact Factor
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ABSTRACT: We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. 34 thyroid gland specimens are imaged from 17 patients, covering a spectrum of pathology ranging from normal thyroid to benign disease/neoplasms (multinodular colloid goiter, Hashimoto's thyroiditis, and follicular adenoma) and malignant thyroid tumors (papillary carcinoma and medullary carcinoma). Imaging is performed using an integrated OCT and OCM system, with <4 microm axial resolution (OCT and OCM), and 14 microm (OCT) and <2 microm (OCM) transverse resolution. The system allows seamless switching between low and high magnifications in a way similar to traditional microscopy. Good correspondence is observed between optical images and histological sections. Characteristic features that suggest malignant lesions, such as complex papillary architecture, microfollicules, psammomatous calcifications, or replacement of normal follicular architecture with sheets/nests of tumor cells, can be identified from OCT and OCM images and are clearly differentiable from normal or benign thyroid tissues. With further development of needle-based imaging probes, OCT and OCM could be promising techniques to use for the screening of thyroid nodules and to improve the diagnostic specificity of fine needle aspiration evaluation.
Journal of Biomedical Optics 15(1):016001. · 3.16 Impact Factor
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ABSTRACT: Optical coherence microscopy (OCM) combines confocal microscopy and optical coherence tomography (OCT) to improve imaging depth and contrast, enabling cellular imaging in human tissues. We aim to investigate OCM for ex vivo imaging of upper and lower gastrointestinal tract tissues, to establish correlations between OCM imaging and histology, and to provide a baseline for future endoscopic studies. Co-registered OCM and OCT imaging were performed on fresh surgical specimens and endoscopic biopsy specimens, and images were correlated with histology. Imaging was performed at 1.06-microm wavelength with <2-microm transverse and <4-microm axial resolution for OCM, and at 14-microm transverse and <3-microm axial resolution for OCT. Multiple sites on 75 tissue samples from 39 patients were imaged. OCM enabled cellular imaging of specimens from the upper and lower gastrointestinal tracts over a smaller field of view compared to OCT. Squamous cells and their nuclei, goblet cells in Barrett's esophagus, gastric pits and colonic crypts, and fine structures in adenocarcinomas were visualized. OCT provided complementary information through assessment of tissue architectural features over a larger field of view. OCM may provide a complementary imaging modality to standard OCT approaches for endoscopic microscopy.
Journal of Biomedical Optics 15(1):016025. · 3.16 Impact Factor
