Evaluation of Single-Impact-Induced Cartilage Degeneration by Optical Coherence Tomography

Posttraumatic osteoarthritis constitutes a major cause of disability in our increasingly elderly population. Unfortunately, current imaging modalities are too insensitive to detect early degenerative changes of this disease. Optical coherence tomography (OCT) is a promising nondestructive imaging technique that allows surface and subsurface imaging of cartilage, at near-histological resolution, and is principally applicablein vivoduring arthroscopy. Thirty-four macroscopically normal human cartilage-bone samples obtained from total joint replacements were subjected to standardized single impactsin vitro(range: 0.25 J to 0.98 J). 3D OCT measurements of impact area and adjacent tissue were performed prior to impaction, directly after impaction, and 1, 4, and 8 days later. OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections. WhileOAIandOHIscores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) andOIIscores. In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

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Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽

10.3390/s21134554 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4554

Author(s):

Ralph-Alexandru Erdelyi ◽

Virgil-Florin Duma ◽

Cosmin Sinescu ◽

George Mihai Dobre ◽

Adrian Bradu ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Radiation Dose ◽

Imaging Techniques ◽

Image Resolution ◽

Optical Coherence ◽

X Rays ◽

High Quality ◽

X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

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Detecting glucose-induced changes in in vitro and in vivo experiments with optical coherence tomography

Journal of Biomedical Optics ◽

10.1117/1.2904957 ◽

2008 ◽

Vol 13 (2) ◽

pp. 021111 ◽

Cited By ~ 24

Author(s):

Matti Kinnunen ◽

Risto Myllylä ◽

Seppo Vainio

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence ◽

In Vivo Experiments ◽

Induced Changes

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A MEMS based Optical Coherence Tomography Imaging System and Optical Biopsy Probes for Real-Time, High Resolution In-Vivo and In-Vitro 2-D or 3-D Imaging

IEEE/LEOS International Conference on Optical MEMS and Their Applications Conference, 2006. ◽

10.1109/omems.2006.1708315 ◽

2006 ◽

Cited By ~ 1

Author(s):

D.T. McCormick ◽

Woonggyu Jung ◽

Yeh-Chan Ahn ◽

V. Milanovic ◽

Zhongping Chen ◽

...

Keyword(s):

Optical Coherence Tomography ◽

High Resolution ◽

Real Time ◽

Imaging System ◽

Optical Biopsy ◽

Optical Coherence ◽

Tomography Imaging ◽

Optical Coherence Tomography Imaging

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Abstract WP1: High-Frequency Optical Coherence Tomography for Cerebrovascular Disease

Stroke ◽

10.1161/str.51.suppl_1.wp1 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Ajit S Puri ◽

Giovanni Ughi ◽

Robert M King ◽

Matthew Gounis

Keyword(s):

Optical Coherence Tomography ◽

Cerebrovascular Disease ◽

High Frequency ◽

Ex Vivo ◽

Thrombus Formation ◽

Image Resolution ◽

Patient Specific ◽

Optical Coherence

Introduction: Optical coherence tomography (OCT) has played an important role in the diagnosis and treatment guidance in coronary artery disease. However, existing OCT systems are not suitable for routine neurovascular applications due to the size and tortuosity of the arteries. Hypothesis: We seek to demonstrate a prototype high-frequency OCT (HF-OCT) capable of high-resolution imaging in simulated cerebrovascular anatomy. Methods: A low-profile HF-OCT system was constructed with an image resolution approaching 10μm. Using an in vitro, patient-specific model of the circle of Willis with circulating porcine blood, we characterized the delivery of the device and ability to image in a tortuous path. Also, human cadaver intracranial atherosclerosis plaques were imaged with HF-OCT and assessed by an expert imager. Finally, neurovascular devices were implanted in 8 pigs (Fig 1) and HF-OCT imaging was compared with gold-standard DSA and CT. Results: In the phantom, optimal blood clearance was achieved through an intermediate catheter (5 Fr Navien) with infusion of contrast at 5 ml/s in the internal carotid and basilar artery, and 3 ml/sec in the MCA. The in vivo study demonstrated that both malapposition of devices or thrombus formation along the device surface could be reliably diagnosed among 3 reviewers (Fleiss’s kappa of 0.87 and 0.9, respectively). This agreement was superior to DSA and CT. Imaging in tortuous swine brachial showed in all cases imaging free of artifacts, uniform illumination and ability to visualize vessel wall layers. Plaque types including ‘lipid pools’, fibrotic, and calcific tissue from cadaver specimens of ICAD could be adequately depicted by HF-OCT. Conclusion: In vitro, in vivo and ex vivo characterization of a novel HF-OCT device has shown it is capable of imaging in the tortuous intracranial vascular anatomy. This technology has to potential to aid in the diagnosis of cerebrovascular disease and guide optimal endovascular treatment.

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In vivo and in vitro diagnostics using Full Field Optical Coherence Tomography

Biomedical Optics and 3-D Imaging ◽

10.1364/biomed.2012.btu3a.95 ◽

2012 ◽

Author(s):

Osnath Assayag ◽

Fabrice Harms ◽

Eugénie Dalimier ◽

Bertrand de Poly ◽

Claude Boccara

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence ◽

In Vitro Diagnostics ◽

Full Field

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Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography

Micromachines ◽

10.3390/mi10010035 ◽

2019 ◽

Vol 10 (1) ◽

pp. 35 ◽

Cited By ~ 1

Author(s):

Meng-Tsan Tsai ◽

Bo-Huei Huang ◽

Chun-Chih Yeh ◽

Kin Fong Lei ◽

Ngan-Ming Tsang

Keyword(s):

Optical Coherence Tomography ◽

Cancer Cell ◽

Cellular Response ◽

Tumor Development ◽

Three Dimensional ◽

Cancer Cell Line ◽

Optical Coherence ◽

Non Invasive

Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.

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Early detection of enamel demineralization by optical coherence tomography

Scientific Reports ◽

10.1038/s41598-019-53567-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Meng-Tsan Tsai ◽

Yen-Li Wang ◽

Ting-Wei Yeh ◽

Hsiang-Chieh Lee ◽

Wen-Ju Chen ◽

...

Keyword(s):

Surface Roughness ◽

Optical Coherence Tomography ◽

Early Stage ◽

Scattering Coefficient ◽

Tooth Surface ◽

Acidic Environment ◽

Optical Coherence ◽

Tooth Demineralization

AbstractEnamel is the outermost layer of the tooth that protects it from invasion. In general, an acidic environment accelerates tooth demineralization, leading to the formation of cavities. Scanning electron microscopy (SEM) is conventionally used as an in vitro tool for the observation of tooth morphology changes with acid attacks. Yet, SEM has intrinsic limitations for the potential application of in vivo detection in the early demineralization process. In this study, a high-resolution optical coherence tomography (OCT) system with the axial and transverse resolutions of 2.0 and 2.7 μm in teeth has been utilized for characterizing the effect of the acidic environment (simulated by phosphoric acid) on the enamel topology. The scattering coefficient and the surface roughness of enamel can be directly derived from the OCT results, enabling a quantitative evaluation of the topology changes with demineralization. The dynamic process induced by the acid application is also recorded and analyzed with OCT, depicting the evolution of the demineralization process on enamel. Notably, the estimated enamel scattering coefficient and surface roughness significantly increase with the application time of acid and the results illustrate that the values of both parameters after demineralization are significantly larger than those obtained before the demineralization, illustrating both parameters could be effective to differentiate the healthy and demineralized teeth and determine the severity. The obtained results unambiguously illustrate that demineralization of the tooth surface can be successfully detected by OCT and further used as an indicator of early-stage cavity formation.

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