Longitudinal Monitoring of Flow-Diverting Stent Tissue Coverage After Implant in a Bifurcation Model Using Neurovascular High-Frequency Optical Coherence Tomography

Abstract BACKGROUND Tissue growth over covered branches is a leading cause of delayed thrombotic complications after flow-diverter stenting (FDS). Due to insufficient resolution, no imaging modality is clinically available to monitor this phenomenon. OBJECTIVE To evaluate high-frequency optical coherence tomography (HF-OCT), a novel intravascular imaging modality designed for the cerebrovascular anatomy with a resolution approaching 10 microns, to monitor tissue growth over FDS in an arterial bifurcation model. METHODS FDS were deployed in a rabbit model (n = 6), covering the aortic bifurcation. The animals were divided in different groups, receiving dual antiplatelet therapy (DAPT) (n = 4), aspirin only (n = 1), and no treatment (n = 1). HF-OCT data were obtained in vivo at 3 different time points in each animal. For each cross-sectional image, metal and tissue coverage of the jailed ostium was quantified. Scanning electron microscopy images of harvested arteries were subsequently obtained. RESULTS Good quality HF-OCT data sets were successfully acquired at implant and follow-up. A median value of 41 (range 21-55) cross-sectional images were analyzed per ostium for each time point. Between 0 and 30 d after implant, HF-OCT analysis showed a significantly higher ostium coverage when DAPT was not given. After 30 d, similar growth rates were found in the DAPT and in the aspirin group. At 60 d, a coverage of 90% was reached in all groups. CONCLUSION HF-OCT enables an accurate visualization of tissue growth over time on FDS struts. The use of FDS in bifurcation locations may induce a drastic reduction of the jailed-branch ostium area.

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Modern Trends in Imaging V: Optical Coherence Tomography for Rapid Tissue Screening and Directed Histological Sectioning

Analytical Cellular Pathology ◽

10.1155/2012/757236 ◽

2012 ◽

Vol 35 (3) ◽

pp. 129-143 ◽

Cited By ~ 11

Author(s):

Woonggyu Jung ◽

Stephen A. Boppart

Keyword(s):

Optical Coherence Tomography ◽

Real Time ◽

Image Guidance ◽

Diagnostic Yield ◽

Imaging Modality ◽

Imaging Techniques ◽

Optical Coherence ◽

Sampling Errors ◽

Cross Sectional

In pathology, histological examination of the “gold standard” to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack ofin vivoobservation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.

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Role of Optical Coherence Tomography on Corneal Surface Laser Ablation

Journal of Ophthalmology ◽

10.1155/2012/676740 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 11

Author(s):

Bruna V. Ventura ◽

Haroldo V. Moraes ◽

Newton Kara-Junior ◽

Marcony R. Santhiago

Keyword(s):

Optical Coherence Tomography ◽

Laser Ablation ◽

Imaging Modality ◽

Corneal Thickness ◽

Optical Coherence ◽

Corneal Surface ◽

Cross Sectional ◽

Surface Laser ◽

The Time Domain

This paper focuses on reviewing the roles of optical coherence tomography (OCT) on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructurein vivo.There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laserin situkeratomileusis (LASIK) and in excimer laser phototherapeutic keratectomy (PTK), OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.

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The Value of Anterior Segment Optical Coherence Tomography in Different Types of Corneal Infections: An Update

Journal of Clinical Medicine ◽

10.3390/jcm10132841 ◽

2021 ◽

Vol 10 (13) ◽

pp. 2841

Author(s):

Ahmed A. Abdelghany ◽

Francesco D’Oria ◽

Jorge Alio Del Barrio ◽

Jorge L. Alio

Keyword(s):

Optical Coherence Tomography ◽

Imaging Modality ◽

Wide Spectrum ◽

Anterior Segment ◽

Corneal Edema ◽

Response To Treatment ◽

Optical Coherence ◽

Slit Lamp ◽

Cross Sectional

Anterior segment optical coherence tomography (AS-OCT) is a modality that uses low-coherence interferometry to visualize and assess anterior segment ocular features, offering several advantages of being a sterile and noncontact modality that generates high-resolution cross-sectional images of the tissues. The qualitative and quantitative information provided by AS-OCT may be extremely useful for the clinician in the assessment of a wide spectrum of corneal infections, guiding in the management and follow-up of these patients. In clinical practice, infections are routinely evaluated with slit-lamp biomicroscopy, an examination and imaging modality that is limited by the physical characteristics of light. As a consequence, the depth of pathology and the eventually associated corneal edema cannot be accurately measured with the slit-lamp. Therefore, it represents a limit for the clinician, as in vivo information about corneal diseases and the response to treatment is limited. Resolution of corneal infection is characterized by an early reduction in corneal edema, followed by a later reduction in infiltration: both parameters can be routinely measured with standardized serial images by AS-OCT.

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Optical coherence tomography of the oval window niche

The Journal of Laryngology & Otology ◽

10.1017/s0022215109004381 ◽

2009 ◽

Vol 123 (6) ◽

pp. 603-608 ◽

Cited By ~ 14

Author(s):

T Just ◽

E Lankenau ◽

G Hüttmann ◽

H W Pau

Keyword(s):

Optical Coherence Tomography ◽

Middle Ear ◽

Imaging Modality ◽

Oval Window ◽

Annular Ligament ◽

Middle Ear Surgery ◽

Optical Coherence ◽

Ear Surgery ◽

Temporal Bones

AbstractObjective:Optical coherence tomography was used to study the stapes footplate, both in cadaveric temporal bones and during middle-ear surgery.Materials and methods:Optical coherence tomography was conducted on five temporal bone preparations (from two children and three adults) and in eight patients during middle-ear surgery. A specially equipped operating microscope with integrated spectral domain optical coherence tomography apparatus was used for standard middle-ear surgical procedures.Results:This optical coherence tomography investigation enabled in vivo visualisation and documentation of the annular ligament, the different layers of the footplate and the inner-ear structures, both in non-fixed and fixed stapes footplates. In cases of otosclerosis and tympanosclerosis, an inhomogeneous and irregularly thickened footplate was found, in contrast to the appearance of non-fixed footplates. In both fixed and non-fixed footplates, there was a lack of visualisation of the border between the footplate and the otic capsule.Conclusions:Investigation of the relatively new technology of optical coherence tomography indicated that this imaging modality may assist the ear surgeon to assess the oval window niche intra-operatively.

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Optical coherence tomography of the pancreatic and bile ducts: are we ready for prime time?

Endoscopy International Open ◽

10.1055/a-1119-6248 ◽

2020 ◽

Vol 08 (05) ◽

pp. E644-E649

Author(s):

Amy Tyberg ◽

Isaac Raijman ◽

Aleksey A. Novikov ◽

Divyesh V. Sejpal ◽

Petros C. Benias ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Pancreatic Duct ◽

Imaging System ◽

Biliary Duct ◽

Optical Coherence ◽

Cross Sectional ◽

Reflective Surface ◽

Cross Sectional Imaging ◽

Sectional Imaging

Abstract Background and study aims First-generation optical coherence tomography (OCT) has been shown to increase diagnostic sensitivity for malignant biliary and pancreatic-duct strictures. A newer OCT imaging system, NVision Volumetric Laser Endomicroscopy (VLE), allows for in vivo cross-sectional imaging of the ductal wall at the microstructure level during endoscopic retrograde cholangiopancreatography (ERCP). The aim of this study was to identify and evaluate characteristics on OCT that are predictive of benign and malignant strictures. Patients and methods Consecutive patients from six centers who underwent OCT between September 2016 and September 2017 were included in a dedicated registry. OCT images were analyzed, and nine recurring characteristics were further assessed. Final diagnosis was based on histology and/or surgical pathology. Results 86 patients were included (49 % male, mean age 64.7). OCT was performed in the bile duct in 79 patients and the pancreatic duct in seven. Nine OCT characteristics were identified: dilated hypo-reflective structures (n = 7), onion-skin layering (n = 8), intact layering (n = 17), layering effacement (n = 25), scalloping (n = 20), thickened epithelium (n = 42), hyper-glandular mucosa (n = 13), prominent blood vessels (n = 6), and a hyper-reflective surface (n = 20). Presence of hyper-glandular mucosa, hyper-reflective surface and scalloping significantly increased the odds of malignancy diagnosis by 6 times more (P = 0.0203; 95 % CI 1.3 to 26.5), 4.7 times more (P = 0.0255; 95 % CI 1.2 to 18.0) and 7.9 times more (P = 0.0035; 95 % CI 1.97 to 31.8) respectively. Conclusion By providing in-vivo cross-sectional imaging of the pancreatic and biliary duct wall, OCT technology may improve sensitivity in diagnosing malignant strictures and provide standardizable criteria predictive of malignancy.

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Comparison of optical coherence tomography and high frequency ultrasound imaging in mice for the assessment of skin morphology and intradermal volumes

Scientific Reports ◽

10.1038/s41598-019-50104-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Kornelia Schuetzenberger ◽

Martin Pfister ◽

Alina Messner ◽

Vanessa Froehlich ◽

Gerhard Garhoefer ◽

...

Keyword(s):

Optical Coherence Tomography ◽

High Frequency ◽

Ex Vivo ◽

Clinical Settings ◽

Optical Coherence ◽

High Frequency Ultrasound ◽

Skin Morphology ◽

Frequency Ultrasound ◽

Good Agreement

Abstract Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS), two established imaging modalities in the field of dermatology, were evaluated and compared regarding their applicability for visualization of skin tissue morphology and quantification of murine intradermal structures. The accuracy and reproducibility of both methods were assessed ex vivo and in vivo using a standardized model for intradermal volumes based on injected soft tissue fillers. OCT revealed greater detail in skin morphology, allowing for detection of single layers due to the superior resolution. Volumetric data measured by OCT (7.9 ± 0.3 μl) and HFUS (7.7 ± 0.5 μl) were in good agreement and revealed a high accuracy when compared to the injected volume of 7.98 ± 0.8 µl. In vivo, OCT provided a higher precision (relative SD: 26% OCT vs. 42% HFUS) for the quantification of intradermal structures, whereas HFUS offered increased penetration depth enabling the visualization of deeper structures. A combination of both imaging technologies might be valuable for tumor assessments or other dermal pathologies in clinical settings.

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Measurement of Vibrating Tympanic Membrane in an In Vivo Mouse Model Using Doppler Optical Coherence Tomography

Journal of Imaging ◽

10.3390/jimaging5090074 ◽

2019 ◽

Vol 5 (9) ◽

pp. 74

Author(s):

Jeon ◽

Kim ◽

Jeon ◽

Kim

Keyword(s):

Optical Coherence Tomography ◽

Phase Shift ◽

Tympanic Membrane ◽

Middle Ear ◽

Acoustic Stimulus ◽

Optical Coherence ◽

Cross Sectional ◽

Vibratory Motion ◽

Doppler Optical Coherence Tomography

Optical coherence tomography (OCT) has a micro-resolution with a penetration depth of about 2 mm and field of view of about 10 mm. This makes OCT well suited for analyzing the anatomical and internal structural assessment of the middle ear. To study the vibratory motion of the tympanic membrane (TM) and its internal structure, we developed a phase-resolved Doppler OCT system using Kasai’s autocorrelation algorithm. Doppler optical coherence tomography is a powerful imaging tool which can offer the micro-vibratory measurement of the tympanic membrane and obtain the micrometer-resolved cross-sectional images of the sample in real-time. To observe the relative vibratory motion of individual sections (malleus, thick regions, and the thin regions of the tympanic membrane) of the tympanic membrane in respect to auditory signals, we designed an experimental study for measuring the difference in Doppler phase shift for frequencies varying from 1 to 8 kHz which were given as external stimuli to the middle ear of a small animal model. Malleus is the very first interconnecting region between the TM and cochlea. In our proposed study, we observed that the maximum change in Doppler phase shift was seen for the 4 kHz acoustic stimulus in the malleus, the thick regions, and in the thin regions of the tympanic membrane. In particular, the vibration signals were higher in the malleus in comparison to the tympanic membrane.

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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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