Analysis of in vivo optical coherence tomography images of human peripheral nerves using texture analysis

2019 ◽  
Author(s):  
Marcel Lenz ◽  
Jens Möller ◽  
Rene Miemiec ◽  
Anne Carolus ◽  
Christopher Brenke ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Texture Analysis ◽  
Peripheral Nerves ◽  
Optical Coherence

Comparison between optical coherence tomography imaging and histological sections of peripheral nerves

2019 ◽  
pp. 1-8
Author(s):  
Anne E. Carolus ◽  
Jens Möller ◽  
Martin R. Hofmann ◽  
Johannes A. P. van de Nes ◽  
Hubert Welp ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Peripheral Nerves ◽  
Imaging Technique ◽  
Structural Features ◽  
Weighted Averaging ◽  
Optical Coherence ◽  
Myelinated Axons ◽  
Averaging Filter ◽  
Perineural Fibrosis

OBJECTIVEOptical coherence tomography (OCT) is an imaging technique that uses the light-backscattering properties of different tissue types to generate an image. In an earlier feasibility study the authors showed that it can be applied to visualize human peripheral nerves. As a follow-up, this paper focuses on the interpretation of the images obtained.METHODSTen different short peripheral nerve specimens were retained following surgery. In a first step they were examined by OCT during, or directly after, surgery. In a second step the nerve specimens were subjected to histological examination. Various steps of image processing were applied to the OCT raw data acquired. The improved OCT images were compared with the sections stained by H & E. The authors assigned the structures in the images to the various nerve components including perineurium, fascicles, and intrafascicular microstructures.RESULTSThe results show that OCT is able to resolve the myelinated axons. A weighted averaging filter helps in identifying the borders of structural features and reduces artifacts at the same time. Tissue-remodeling processes due to injury (perineural fibrosis or neuroma) led to more homogeneous light backscattering. Anterograde axonal degeneration due to sharp injury led to a loss of visible axons and to an increase of light-backscattering tissue as well. However, the depth of light penetration is too small to allow generation of a complete picture of the nerve.CONCLUSIONSOCT is the first in vivo imaging technique that is able to resolve a nerve’s structures down to the level of myelinated axons. It can yield information about focal and segmental pathologies.

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.

Texture analysis of optical coherence tomography speckle for characterizing biological tissues in vivo

2013 ◽  
Vol 38 (8) ◽  
pp. 1280 ◽  
Author(s):  
Andras A. Lindenmaier ◽  
Leigh Conroy ◽  
Golnaz Farhat ◽  
Ralph S. DaCosta ◽  
Costel Flueraru ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Texture Analysis ◽  
Biological Tissues ◽  
Optical Coherence

258: Diagnosis and Intraoperative Staging of Bladder Disease by in-vivo Optical Coherence Tomography (OCT)

2004 ◽  
Vol 171 (4S) ◽  
pp. 68-68 ◽  
Author(s):  
Markus D. Sachs ◽  
Dmitry Daniltchenko ◽  
Eva Lankenau ◽  
Frank Koenig ◽  
Gerion Huettmann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Bladder Disease

scholarly journals Evaluating Retinal and Choroidal Perfusion Changes after Isometric and Dynamic Activity Using Optical Coherence Tomography Angiography

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 808
Author(s):  
Max Philipp Brinkmann ◽  
Nikolas Xavier Kibele ◽  
Michelle Prasuhn ◽  
Vinodh Kakkassery ◽  
Mario Damiano Toro ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Isometric Exercise ◽  
Dynamic Exercise ◽  
Exercise Heart Rate ◽  
Optical Coherence ◽  
Dynamic Activity ◽  
Capillary Plexus ◽  
Choroidal Perfusion

Optical coherence tomography angiography (OCTA) is a non-invasive tool for imaging and quantifying the retinal and choroidal perfusion state in vivo. This study aimed to evaluate the acute effects of isometric and dynamic exercise on retinal and choroidal sublayer perfusion using OCTA. A pilot study was conducted on young, healthy participants, each of whom performed a specific isometric exercise on the first day and a dynamic exercise the day after. At baseline and immediately after the exercise, heart rate (HR), mean arterial pressure (MAP), superficial capillary plexus perfusion (SCPP), deep capillary plexus perfusion (DCPP), choriocapillaris perfusion (CCP), Sattlers’s layer perfusion (SLP), and Haller’s layer perfusion (HLP) were recorded. A total of 34 eyes of 34 subjects with a mean age of 32.35 ± 7.87 years were included. HR as well as MAP increased significantly after both types of exercise. Both SCPP and DCPP did not show any significant alteration due to isometric or dynamic exercise. After performing dynamic exercise, CCP, SLP, as well as HLP significantly increased. Changes in MAP correlated significantly with changes in HLP after the dynamic activity. OCTA-based analysis in healthy adults following physical activity demonstrated a constant retinal perfusion, supporting the theory of autoregulatory mechanisms. Dynamic exercise, as opposed to isometric activity, significantly changed choroidal perfusion. OCTA imaging may represent a novel and sensitive tool to expand the diagnostic spectrum in the field of sports medicine.

scholarly journals Quantitative Swept-Source Optical Coherence Tomography of Early Enamel Erosion in vivo

2017 ◽  
Vol 51 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Rupert S. Austin ◽  
Maisalamah Haji Taha ◽  
Frederic Festy ◽  
Richard Cook ◽  
Manoharan Andiappan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Volunteers ◽  
Orange Juice ◽  
Signal Intensity ◽  
Surface States ◽  
Enamel Surface ◽  
Optical Coherence ◽  
Swept Source ◽  
Water Rinsing

Swept-source optical coherence tomography (SS-OCT) shows potential for the in vivo quantitative evaluation of micro-structural enamel surface phenomena occurring during early erosive demineralization. This randomized controlled single-blind cross-over clinical study aimed to evaluate the use of SS-OCT for detecting optical changes in the enamel of 30 healthy volunteers subjected to orange juice rinsing (erosive challenge) in comparison to mineral water rinsing (control), according to wiped and non-wiped enamel surface states. Participants were randomly allocated to 60 min of orange juice rinsing (pH 3.8) followed by 60 min of water rinsing (pH 6.7) and vice versa, with a 2-week wash-out period. In addition, the labial surfaces of the right or left maxillary incisors were wiped prior to SS-OCT imaging. An automated ImageJ algorithm was designed to analyse the back-scattered OCT signal intensity (D) after orange juice rinsing compared to after water rinsing. D was quantified as the OCT signal scattering from the 33 µm sub-surface enamel, normalised by the total OCT signal intensity entering the enamel. The back-scattered OCT signal intensity increased by 3.1% (95% CI 1.1-5.1%) in the wiped incisors and by 3.5% (95% CI 1.5-5.5%) in the unwiped incisors (p < 0.0001). Wiping reduced the back-scattered OCT signal intensity by 1.7% (95% CI -3.2 to -0.3%; p = 0.02) in comparison to the unwiped enamel surfaces for both rinsing solutions (p = 0.2). SS-OCT detected OCT signal changes in the superficial sub-surface enamel of maxillary central incisor teeth of healthy volunteers after orange juice rinsing.

In vivo cellular optical coherence tomography imaging

1998 ◽  
Vol 4 (7) ◽  
pp. 861-865 ◽  
Author(s):  
Stephan A. Boppart ◽  
Brett E. Bouma ◽  
Costas Pitris ◽  
James F. Southern ◽  
Mark E. Brezinski ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Tomography Imaging ◽  
Optical Coherence Tomography Imaging

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

Sensors ◽  
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.

scholarly journals Multi-center clinical study using optical coherence tomography for evaluation of cervical lesions in-vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenchen Ren ◽  
Xianxu Zeng ◽  
Zhongna Shi ◽  
Chunyan Wang ◽  
Huifen Wang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Precancerous Lesions ◽  
Diagnostic Value ◽  
Optical Coherence ◽  
Cervical Lesions ◽  
In Vivo Evaluation ◽  
Histological Sections ◽  
Histological Images

AbstractIn this prospective study of an in-vivo cervical examination using optical coherence tomography (OCT), we evaluated the diagnostic value of non-invasive and real-time OCT in cervical precancerous lesions and cancer diagnosis, and determined the characteristics of OCT images. 733 patients from 5 Chinese hospitals were inspected with OCT and colposcopy-directed biopsy. The OCT images were compared with the histological sections to find out the characteristics of various categories of lesions. The OCT images were also interpreted by 3 investigators to make a 2-class classification, and the results were compared against the pathological results. Various structures of the cervical tissue were clearly observed in OCT images, which matched well with the corresponding histological sections. The OCT diagnosis results delivered a sensitivity of 87.0% (95% confidence interval, CI 82.2–90.7%), a specificity of 84.1% (95% CI 80.3–87.2%), and an overall accuracy of 85.1%. Both good consistency of OCT images and histological images and satisfactory diagnosis results were provided by OCT. Due to its features of non-invasion, real-time, and accuracy, OCT is valuable for the in-vivo evaluation of cervical lesions and has the potential to be one of the routine cervical diagnosis methods.

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