scholarly journals Neuroendovascular Optical Coherence Tomography Imaging and Histological Analysis

Neurosurgery ◽  
2011 ◽  
Vol 69 (2) ◽  
pp. 430-439 ◽  
Author(s):  
Marlon S. Mathews ◽  
Jianping Su ◽  
Esmaeil Heidari ◽  
Elad I. Levy ◽  
Mark E. Linskey ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Carotid Arteries ◽  
Ex Vivo ◽  
Infrared Light ◽  
Optical Coherence ◽  
The Common ◽  
Oct Imaging ◽  
Common Carotid Arteries

Abstract BACKGROUND: Intravascular optical coherence tomography (OCT) is a recently developed optical imaging technique that provides high-resolution cross-sectional in situ images from intact tissue based on tissue reflectance of near-infrared or infrared light. OBJECTIVE: To report on the feasibility of neuroendovascular OCT imaging and compare the neuroendovascular OCT findings with histology in nondiseased vessels in an animal, cadaveric, and clinical study. METHODS: Catheter-based in vivo endovascular OCT imaging was performed in the common carotid arteries of 2 pigs and in the intracranial carotid arteries of 3 patients. The endovascular OCT device was delivered to the desired location via groin access and using standard endovascular procedures. Images were obtained via rotational and translational scanning using external motors. In vivo findings were reproduced using ex vivo OCT imaging in corresponding animal and human (cadaveric) harvested tissue segments. These segments underwent histological examination for comparison. RESULTS: The structural compositions of the OCT-imaged segments of the common carotid arteries in pigs as well as the petrous and cavernous intracranial carotid arteries in patients were visualized at high resolution (8 μm). The in vivo images were identical to those obtained ex vivo, demonstrating the imaging capabilities of the endovascular OCT device. The OCT images correlated well with the images obtained after histological sectioning and visualized in vivo the laminar vascular structure. CONCLUSION: Neuroendovascular OCT imaging is feasible for clinical use and can detect with high resolution the structure of arterial segments. Understanding OCT imaging in nondiseased arteries is important in establishing baseline findings necessary for interpreting pathological processes. This allows neuroendovascular optical biopsies of vascular tissue to be obtained without the need for excision and processing.

High-resolution optical coherence tomography (OCT) imaging of human kidney ex vivo

2009 ◽  
Author(s):  
Anik Duttaroy ◽  
Andrew Paek ◽  
Maristela Onozato ◽  
Bobak Shirmahamoodi ◽  
James Jiang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Ex Vivo ◽  
Human Kidney ◽  
Optical Coherence ◽  
Oct Imaging

Novel method using 3-dimensional segmentation in spectral domain-optical coherence tomography imaging in the chick reveals defocus-induced regional and time-sensitive asymmetries in the choroidal thickness

2016 ◽  
Vol 33 ◽  
Author(s):  
DIANE R. NAVA ◽  
BHAVNA ANTONY ◽  
LI ZHANG ◽  
MICHAEL D. ABRÀMOFF ◽  
CHRISTINE F. WILDSOET
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Choroidal Thickness ◽  
Optical Coherence ◽  
3 Dimensional ◽  
Choroidal Thickening ◽  
Area Centralis ◽  
Oct Imaging ◽  
Sd Oct

AbstractStudies into the mechanisms underlying the active emmetropization process by which neonatal refractive errors are corrected, have described rapid, compensatory changes in the thickness of the choroidal layer in response to imposed optical defocus. While high frequency A-scan ultrasonography, as traditionally used to characterize such changes, offers good resolution of central (on-axis) changes, evidence of local retinal control mechanisms make it imperative that more peripheral, off-axis changes also be tracked. In this study, we used in vivo high resolution spectral domain-optical coherence tomography (SD-OCT) imaging in combination with the Iowa Reference Algorithms for 3-dimensional segmentation, to more fully characterize these changes, both spatially and temporally, in young, 7-day old chicks (n = 15), which were fitted with monocular +15 D defocusing lenses to induce choroidal thickening. With these tools, we were also able to localize the retinal area centralis, which was used as a landmark along with the ocular pectin in standardizing the location of scans and aligning them for subsequent analyses of choroidal thickness (CT) changes across time and between eyes. Values were derived for each of four quadrants, centered on the area centralis, and global CT values were also derived for all eyes. Data were compared with on-axis changes measured using ultrasonography. There were significant on-axis choroidal thickening that was detected after just one day of lens wear (∼190 µm), and regional (quadrant-related) differences in choroidal responses were also found, as well as global thickness changes 1 day after treatment. The ratio of global to on-axis choroidal thicknesses, used as an index of regional variability in responses, was also found to change significantly, reflecting the significant central changes. In summary, we demonstrated in vivo high resolution SD-OCT imaging, used in combination with segmentation algorithms, to be a viable and informative approach for characterizing regional (spatial), time-sensitive changes in CT in small animals such as the chick.

scholarly journals Ex vivo High-resolution Optical Coherence Tomography (OCT) Imaging of Pleural Reaction after Pleurodesis Using Talc

2016 ◽  
Vol 20 (5) ◽  
pp. 607-613
Author(s):  
Yeh-Chan Ahn ◽  
Chulho Oak ◽  
Jung-Eun Park ◽  
Min-Jung Jung ◽  
Jae-Hun Kim ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Ex Vivo ◽  
Optical Coherence ◽  
Oct Imaging

High-resolution in vivo imaging of peripheral nerves using optical coherence tomography: a feasibility study

2020 ◽  
Vol 132 (6) ◽  
pp. 1907-1913 ◽  
Author(s):  
Anne E. Carolus ◽  
Marcel Lenz ◽  
Martin Hofmann ◽  
Hubert Welp ◽  
Kirsten Schmieder ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Peripheral Nerves ◽  
Imaging Technique ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Optical Biopsy ◽  
Optical Coherence

OBJECTIVEBecause of their complex topography, long courses, and small diameters, peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include MRI and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical coherence tomography (OCT) is the first imaging technique that is able to depict a nerve’s ultrastructure at micrometer resolution. In the current study, the authors present an in vivo assessment of human peripheral nerves using OCT.METHODSOCT measurement was performed in 34 patients with different peripheral nerve pathologies, i.e., nerve compression syndromes. The nerves were examined during surgery after their exposure. Only the sural nerve was twice examined ex vivo. The Thorlabs OCT systems Callisto and Ganymede were used. For intraoperative use, a hand probe was covered with a sterile foil. Different postprocessing imaging techniques were applied and evaluated. In order to highlight certain structures, five texture parameters based on gray-level co-occurrence matrices were calculated according to Haralick.RESULTSThe intraoperative use of OCT is easy and intuitive. Image artifacts are mainly caused by motion and the sterile foil. If the artifacts are kept at a low level, the hyporeflecting bundles of nerve fascicles and their inner parts can be displayed. In the Haralick evaluation, the second angular moment is most suitable to depict the connective tissue.CONCLUSIONSOCT is a new imaging technique that has shown promise in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable and have already been demonstrated by other groups. Currently, the method resembles an optical biopsy and can be a supplement to intraoperative sonography, giving high-resolution insight into a suspect area that has been located by sonography in advance.

305 Speckle-Free and Large Gold Nanorod Enhanced Optical Coherence Tomography for Brain Tumor Margin Detection

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 264-264 ◽  
Author(s):  
Derek W Yecies ◽  
Orly Liba ◽  
Elliot SoRelle ◽  
Rebecca Dutta ◽  
Christy Wilson ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Brain Tumor ◽  
Ex Vivo ◽  
Cellular Level ◽  
Large Field ◽  
Optical Coherence ◽  
Tumor Margin ◽  
Oct Imaging ◽  
Margin Detection

Abstract INTRODUCTION Optical coherence tomography (OCT) is an emerging technology with the potential to allow for rapid intraoperative detection of brain tumor margins by detecting differences in structure, intensity, spectral signal, and attenuation. OCT systems are capable of rapid imaging of large three-dimensional volumes with cellular level resolution. However, OCT imaging has previously been limited by speckle artifact and the lack of suitable contrast agents, limitations that are surmounted in this study. METHODS We prepared nude mice with orthotopic U87 glioblastoma xenografts and glass cranial windows. We also created large gold nanorods (LGNR) with plasmonic peaks tuned to the spectral range of the OCT scanner. LGNRs were injected intravenously into tumor-bearing mice and OCT imaging was performed in vivo utilizing a novel method for the removal of speckle artifact called Speckle-Free OCT (SFOCT). Fresh ex-vivo patient samples were also imaged. RESULTS >OCT and SFOCT readily distinguished tumor from normal brain with cellular level spatial resolution and to a depth of 1.5 mm. Additionally, SFOCT allowed for the highest resolution ever seen in vivo of mouse white matter architecture. Cortical layers were also readily visible in SFOCT in both live mice and in the ex-vivo human samples, representing a novel ability to interrogate cortical cytoarchitecture across a large field of view. Systemically administered LGNRs were tumor specific and provided excellent spectral contrast using OCT. Ex-vivo hyperspectral and IHC imaging confirmed the localization of LGNRs within the tumor and found that the LGNRs were largely localized within tumor associated macrophages. CONCLUSION SFOCT and LGNR enhanced OCT imaging are promising state of the art technologies for intraoperative tumor margin detection.

Ex Vivo assessment of competent strut coverage after coronary stenting by optical coherence tomography

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
R Bhoite ◽  
H Jinnouchi ◽  
F Otsuka ◽  
Y Sato ◽  
A Sakamoto ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Predictive Value ◽  
Ex Vivo ◽  
High Sensitivity ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Neointimal Thickness ◽  
Stent Strut ◽  
Oct Imaging ◽  
Definition Of

Abstract Background In many studies, struts coverage is defined as >0 mm of tissue overlying the stent struts by optical coherence tomography (OCT). However, this definition has never been validated using histology as the “gold standard”. The present study sought to assess the appropriate cut-off value of neointimal thickness of stent strut coverage by OCT using histology. Methods OCT imaging was performed on 39 human coronary arteries with stents from 25 patients at autopsy. A total of 165 cross-sectional images from 46 stents were co-registered with histology. The optimal cut-off value of strut coverage by OCT was determined. Strut coverage by histology was defined as endothelial cells with at least underlying two layers of smooth muscle cells. Considering the resolution of OCT is 10–20 μm, 3 different cut-off values (i.e. at ≥20, ≥40, and ≥60 μm) were assessed. Results A total of 2235 struts were evaluated by histology. Eventually, 1216 struts which were well-matched struts were analyzed in this study. By histology, uncovered struts were observed in 160 struts and covered struts were observed in 1056 struts. The broadly used definition of OCT-coverage which does not consider neointimal thickness yielded a poor specificity of 37.5% and high sensitivity 100%. Of 3 cut-off values, the cut-off value of >40 μm was more accurate as compared to >20 and >60 mm [sensitivity (99.3%), specificity (91.0%), positive predictive value (98.6%), and negative predictive value (95.6%)] Conclusion The most accurate cut-off value was ≥40 μm neointimal thickness by OCT in order to identify stent strut coverage validated by histology. Funding Acknowledgement Type of funding source: None

scholarly journals Polarization sensitive optical coherence tomography with single input for imaging depth-resolved collagen organizations

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Peijun Tang ◽  
Mitchell A. Kirby ◽  
Nhan Le ◽  
Yuandong Li ◽  
Nicole Zeinstra ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Structural Integrity ◽  
Ex Vivo ◽  
Polarization State ◽  
Transmission Model ◽  
Optical Coherence ◽  
Healthy Human ◽  
Collagen Organization ◽  
Single Input

AbstractCollagen organization plays an important role in maintaining structural integrity and determining tissue function. Polarization-sensitive optical coherence tomography (PSOCT) is a promising noninvasive three-dimensional imaging tool for mapping collagen organization in vivo. While PSOCT systems with multiple polarization inputs have demonstrated the ability to visualize depth-resolved collagen organization, systems, which use a single input polarization state have not yet demonstrated sufficient reconstruction quality. Herein we describe a PSOCT based polarization state transmission model that reveals the depth-dependent polarization state evolution of light backscattered within a birefringent sample. Based on this model, we propose a polarization state tracing method that relies on a discrete differential geometric analysis of the evolution of the polarization state in depth along the Poincare sphere for depth-resolved birefringent imaging using only one single input polarization state. We demonstrate the ability of this method to visualize depth-resolved myocardial architecture in both healthy and infarcted rodent hearts (ex vivo) and collagen structures responsible for skin tension lines at various anatomical locations on the face of a healthy human volunteer (in vivo).

196 IN-VIVO HIGH RESOLUTION THORACOSCOPIC OPTICAL COHERENCE TOMOGRAPHY IMAGING OF INDUCED PLEURAL TUMORS

2005 ◽  
Vol 53 (1) ◽  
pp. S112.3-S112
Author(s):  
J. Armstrong ◽  
E. Matheny ◽  
K. Kreuter ◽  
N. Hanna ◽  
Z. Chen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Optical Coherence ◽  
Tomography Imaging ◽  
Optical Coherence Tomography Imaging
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