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.

scholarly journals Theranostic applications of optical coherence tomography in neurosurgery?

2021 ◽  
Author(s):  
Karl Hartmann ◽  
Klaus-Peter Stein ◽  
Belal Neyazi ◽  
I. Erol Sandalcioglu
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging Technique ◽  
Intraoperative Imaging ◽  
Tumor Resection ◽  
Minimal Invasive ◽  
Cochrane Library ◽  
Optical Coherence ◽  
Perioperative Morbidity ◽  
Integrated Optical

Abstract In light of our own experiences, we value the existing literature to critically point out possible “near” future applications of optical coherence tomography (OCT) as an intraoperative neurosurgical guidance tool. “Pub Med”, “Cochrane Library”, “Crossref Metadata Search”, and “IEEE Xplore” databases as well as the search engine “Google Scholar” were screened for “optical coherence tomography + neurosurgery”, “optical coherence tomography + intraoperative imaging + neurosurgery”, and “microscope integrated optical coherence tomography + neurosurgery”. n = 51 articles related to the use of OCT as an imaging technique in the field of neurosurgery or neurosurgical research. n = 7 articles documented the intraoperative use of OCT in patients. n = 4 articles documented the use of microscope-integrated optical coherence tomography as a neurosurgical guidance tool. The Results demonstrate that OCT is the first imaging technique to study microanatomy in vivo. Postoperative analysis of intraoperative scans holds promise to enrich our physiological and pathophysiological understanding of the human brain. No data exists to prove that OCT-guided surgery minimizes perioperative morbidity or extends tumor resection. But results suggest that regular use of microscope-integrated OCT could increase security during certain critical microsurgical steps like, e.g., dural dissection at cavernous sinus, transtentorial approaches, or aneurysm clip placement. Endoscopy integration could aid surgery in regions which are not yet accessible to real-time imaging modalities like the ventricles or hypophysis. Theranostic instruments which combine OCT with laser ablation might gain importance in the emerging field of minimal invasive tumor surgery. OCT depicts vessel wall layers and its pathologies uniquely. Doppler OCT could further visualize blood flow in parallel. These abilities shed light on promising future applications in the field of vascular neurosurgery.

scholarly journals Morphology of Peripheral Vitreoretinal Interface Abnormalities Imaged with Spectral Domain Optical Coherence Tomography

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Rachel L. Chu ◽  
Nicole A. Pannullo ◽  
Christopher R. Adam ◽  
Mohammad R. Rafieetary ◽  
Eric J. Sigler
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Imaging Modality ◽  
Structural Features ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Vitreoretinal Interface ◽  
Retinal Breaks ◽  
Sd Oct

The objective of this study is to describe the clinical utility and morphologic characteristics of peripheral vitreoretinal interface abnormalities with spectral domain optical coherence tomography (SD-OCT). A prospective imaging analysis of 43 patients with peripheral vitreoretinal interface abnormalities seen on binocular indirect examination with scleral indentation was done. SD-OCT was evaluated for image quality and structural findings. Laser retinopexy was performed to surround all retinal breaks containing a full-thickness component via SD-OCT. Acceptable image quality for inclusion was obtained in 39/43 (91%) patients. Mean age was 41 ± 22 years, and mean follow-up was 14 ± 1.6 months. Decision to treat was altered following SD-OCT in 5% of the patients. Two cases of previously diagnosed operculated holes were found on SD-OCT to be partial-thickness operculated breaks or focal operculated schisis. Peripheral SD-OCT is a reliable and useful technique to examine the structural features of vitreoretinal interface abnormalities in vivo. This imaging modality is useful in the clinical management of suspected retinal breaks identified with indirect ophthalmoscopy.

scholarly journals In-Vivo Functional and Structural Retinal Imaging Using Multiwavelength Photoacoustic Remote Sensing Microscopy and Optical Coherence Tomography

2021 ◽  
Author(s):  
Zohreh Hosseinaee ◽  
Nicholas Pellegrino ◽  
Nima Abbasi ◽  
Tara Amiri ◽  
James A. Tummon Simmons ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Coherence Tomography ◽  
Oxygen Saturation ◽  
Imaging Technique ◽  
Photoacoustic Imaging ◽  
Retinal Imaging ◽  
Optical Coherence ◽  
Swept Source ◽  
First Time

Abstract A multiwavelength photoacoustic remote sensing (PARS) microscope is combined with swept-source optical coherence tomography and applied to in-vivo, non-contact retinal imaging. Building on the proven strength of multiwavelength PARS imaging, the system is applied for estimating retinal oxygen saturation in the rat eye. The capability of the technology is demonstrated by imaging both microanatomy and the microvasculature of the retina in-vivo. To our knowledge, this is the first time a non-contact photoacoustic imaging technique is employed for in-vivo oxygen saturation measurement in the retina.

Efficient Synchronization and Reconstruction of 4D Non-Gated Cardiac Images of Chick Embryos Obtained From Optical Coherence Tomography

2009 ◽  
Author(s):  
Aiping Liu ◽  
Ruikang Wang ◽  
Kent L. Thornburg ◽  
Sandra Rugonyi
Keyword(s):  
Optical Coherence Tomography ◽  
Slow Rate ◽  
Cardiac Development ◽  
Imaging Technique ◽  
Image Data ◽  
Optical Coherence ◽  
4D Imaging ◽  
3D Volume ◽  
And Function

Four-dimensional (4D) imaging with optical coherence tomography (OCT) — a high-resolution, noninvasive tomographic imaging technique — applied to cardiac development can be used to study the interaction of cardiac morphology and function in vivo. However, to image the fast beating embryonic heart, the biggest challenge confronted by current OCT systems is the slow rate of 3D volume image data acquisition.

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