Longitudinal in-vivo quantification of tumour microvasculature heterogeneity via optical coherence tomography (OCT) angiography in a pre-clinical model of radiation therapy

2021 ◽  
Author(s):  
Nader Allam ◽  
W. Jeffrey Zabel ◽  
Blake Jones ◽  
Valentin Demidov ◽  
Edward Taylor ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Radiation Therapy ◽  
Oct Angiography ◽  
Optical Coherence ◽  
Clinical Model

scholarly journals Micro-Heterogeneity of Flow in a Mouse Model of Chronic Cerebral Hypoperfusion Revealed by Longitudinal Doppler Optical Coherence Tomography and Angiography

2015 ◽  
Vol 35 (10) ◽  
pp. 1552-1560 ◽  
Author(s):  
Vivek J Srinivasan ◽  
Esther Yu ◽  
Harsha Radhakrishnan ◽  
Anil Can ◽  
Mihail Climov ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Capillary Density ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Oct Angiography ◽  
Imaging Method ◽  
Optical Coherence ◽  
Doppler Optical Coherence Tomography ◽  
Longitudinal Imaging

Although microvascular dysfunction accompanies cognitive decline in aging, vascular dementia, and Alzheimer's disease, tools to study microvasculature longitudinally in vivo are lacking. Here, we use Doppler optical coherence tomography (OCT) and angiography for noninvasive, longitudinal imaging of mice with chronic cerebral hypoperfusion for up to 1 month. In particular, we optimized the OCT angiography method to selectively image red blood cell (RBC)-perfused capillaries, leading to a novel way of assessing capillary supply heterogeneity in vivo. After bilateral common carotid artery stenosis (BCAS), cortical blood flow measured by Doppler OCT dropped to half of baseline throughout the imaged tissue acutely. Microscopic imaging of the capillary bed with OCT angiography further revealed local heterogeneities in cortical flow supply during hypoperfusion. The number of RBC-perfused capillaries decreased, leading to increased oxygen diffusion distances in the days immediately after BCAS. Linear regression showed that RBC-perfused capillary density declined by 0.3% for a drop in flow of 1 mL/100 g per minute, and decreases in RBC-perfused capillary density as high as 25% were observed. Taken together, these results demonstrate the existence of local supply heterogeneity at the capillary level even at nonischemic global flow levels, and demonstrate a novel imaging method to assess this heterogeneity.

scholarly journals Functional OCT angiography reveals early physiological dysfunction of hyaloid vasculature in developing mouse eye

2019 ◽  
Vol 244 (10) ◽  
pp. 819-823 ◽  
Author(s):  
Tae-Hoon Kim ◽  
Taeyoon Son ◽  
Xincheng Yao
Keyword(s):  
Optical Coherence Tomography ◽  
Vascular System ◽  
Eye Development ◽  
Vision System ◽  
Longitudinal Optical ◽  
Oct Angiography ◽  
Full Description ◽  
Optical Coherence ◽  
Hyaloid Vasculature

Hyaloid vascular system (HVS) is a transient capillary network nourishing developing eye. Better study of the HVS regression correlated with eye development is essential for in-depth understanding of the nature of vision system. In this study, we demonstrate the feasibility of longitudinal optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of the HVS in C57BL/6J mice. OCT enables morphological monitoring of the HVS regression, and OCTA allows physiological assessment of the HVS involution correlated with eye development. Functional OCTA reveals early physiological dysfunction before morphological regression of the hyaloid vasculature in developing mouse eye. We anticipate that noninvasive, simultaneous OCT/OCTA observation of morphological regression and physiological degradation in normal and diseased animal models will be valuable to unravel the complex mechanisms of the HVS regression correlated with normal eye development and abnormal persistent hyaloid conditions. Impact statement Hyaloid vascular system (HVS) is known to have an essential role in the eye development. However, established knowledge of the HVS largely relies on end-point studies with biochemically fixed tissues, lacking a full description of the natural dynamics of the HVS correlated with eye development. An imaging methodology for noninvasive, longitudinal, and high-resolution monitoring of the HVS is important not only for better understanding of the nature of the vision system and is also valuable for better study of abnormal eye conditions. Here, we report the feasibility of in vivo optical coherence tomography (OCT) and OCT angiography (OCTA) imaging of the HVS regression in developing mouse eye. OCT enables morphological imaging of the HVS structure, and OCTA allows functional assessment of the HVS physiology correlated with eye development.

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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