scholarly journals Sensor-Based Technique for Manually Scanned Hand-Held Optical Coherence Tomography Imaging

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Paritosh Pande ◽  
Guillermo L. Monroy ◽  
Ryan M. Nolan ◽  
Ryan L. Shelton ◽  
Stephen A. Boppart

Hand-held optical coherence tomography (OCT) imaging probes offer flexibility to image sites that are otherwise challenging to access. While the majority of hand-held imaging probes utilize galvanometer- or MEMS-scanning mirrors to transversely scan the imaging beam, these probes are commonly limited to lateral fields-of-view (FOV) of only a few millimeters. The use of a freehand manually scanned probe can significantly increase the lateral FOV. However, using the traditional fixed-rate triggering scheme for data acquisition in a manually scanned probe results in imaging artifacts due to variations in the scan velocity of the imaging probe. These artifacts result in a structurally inaccurate image of the sample. In this paper, we present a sensor-based manual scanning technique for OCT imaging, where real-time feedback from an optical motion sensor is used to trigger data acquisition. This technique is able to circumvent the problem of motion artifacts during manual scanning by adaptively altering the trigger rate based on the instantaneous scan velocity, enabling OCT imaging over a large lateral FOV. The feasibility of the proposed technique is demonstrated by imaging several biological and nonbiological samples.

2016 ◽  
Vol 26 (03) ◽  
pp. 191-195
Author(s):  
Pranav Patel ◽  
Alisha Grewal ◽  
Prabhsimran Mohar ◽  
Morton Kern ◽  
Dilbahar Mohar

Although the use of drug-eluting stents (DES) has dramatically decreased the incidence of in-stent restenosis (ISR), concerns regarding the late manifestations of ISR remain. Optical coherence tomography (OCT) imaging provides unique insights into characteristics and patterns of ISR. We report a case of late DES ISR with unusual heterogeneous intracoronary luminal characteristics suggestive of vulnerable atherosclerotic plaque activity by OCT imaging. This case demonstrates that late ISR after DES may involve more than mere neointimal hyperplasia with lesion-associated craters, septae, and neoatherosclerosis. The use of OCT provides novel insights into the mechanisms and potential biology of the late DES ISR.


2020 ◽  
Vol 12 ◽  
pp. 251584142092319
Author(s):  
Andrew Walkden ◽  
Olivia Atkinson ◽  
Emma Linton ◽  
Adam Bull ◽  
Laina Abraham ◽  
...  

Aim: The aim of this study was to prospectively define the characteristics and outcomes of a cohort of central serous chorioretinopathy patients using optical coherence tomography imaging to determine anatomical disease resolution. Much of the literature available on the characteristics of central serous chorioretinopathy patients pre date the advent of OCT imaging, with conclusive epidemiological evidence being scarce. We describe a cohort of patients presenting to a large centre over the course of a year. Methods: Prospective data collection was undertaken for all patients diagnosed with central serous chorioretinopathy at our unit over the course of 1 year. All patients underwent thorough history taking and optical coherence tomography imaging. Results: In total, 59 eyes from 51 patients were diagnosed with central serous chorioretinopathy between April 2017 and April 2018; 23 (45.1%) patients had optical coherence tomography evidence of complete anatomical resolution within a year, with three (5.88%) patients suffering a worse visual acuity compared with that at presentation at 1-year end point; and three patients developed secondary choroidal neovascular membranes. Conclusion: Our study reports much-needed prospective outcomes of patients with central serous chorioretinopathy, which helps to guide clinicians when deciding treatment strategies, as well as better informing patients of their prognosis for visual improvement.


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2313
Author(s):  
Mohamed Elsharkawy ◽  
Mostafa Elrazzaz ◽  
Mohammed Ghazal ◽  
Marah Alhalabi ◽  
Ahmed Soliman ◽  
...  

In developed countries, age-related macular degeneration (AMD), a retinal disease, is the main cause of vision loss in the elderly. Optical Coherence Tomography (OCT) is currently the gold standard for assessing individuals for initial AMD diagnosis. In this paper, we look at how OCT imaging can be used to diagnose AMD. Our main aim is to examine and compare automated computer-aided diagnostic (CAD) systems for diagnosing and grading of AMD. We provide a brief summary, outlining the main aspects of performance assessment and providing a basis for current research in AMD diagnosis. As a result, the only viable alternative is to prevent AMD and stop both this devastating eye condition and unwanted visual impairment. On the other hand, the grading of AMD is very important in order to detect early AMD and prevent patients from reaching advanced AMD disease. In light of this, we explore the remaining issues with automated systems for AMD detection based on OCT imaging, as well as potential directions for diagnosis and monitoring systems based on OCT imaging and telemedicine applications.


2010 ◽  
Vol 15 (6) ◽  
pp. 066027 ◽  
Author(s):  
Woonggyu Jung ◽  
Wladimir Benalcazar ◽  
Adeel Ahmad ◽  
Utkarsh Sharma ◽  
Haohua Tu ◽  
...  

Author(s):  
Rajgopal Mani ◽  
Jon Holmes ◽  
Kittipan Rerkasem ◽  
Nikolaos Papanas

Dynamic optical coherence tomography (D-OCT) is a relatively new technique that may be used to study the substructures in the retina, in the skin and its microcirculation. Furthermore, D-OCT is a validated method of imaging blood flow in skin microcirculation. The skin around venous and mixed arterio-venous ulcers was imaged and found to have tortuous vessels assumed to be angiogenic sprouts, and classified as dots, blobs, coils, clumps, lines, and curves. When these images were analyzed and measurements of vessel density were made, it was observed that the prevalence of coils and clumps in wound borders was significantly greater compared with those at wound centers. This reinforced the belief of inward growth of vessels from wound edge toward wound center which, in turn, reposed confidence in following the wound edge to study healing. D-OCT imaging permits the structure and the function of the microcirculation to be imaged, and vessel density measured. This offers a new vista of skin microcirculation and using it, to better understand angiogenesis in chronic wounds.


2021 ◽  
pp. 247412642199733
Author(s):  
Kyle D. Kovacs ◽  
M. Abdallah Mahrous ◽  
Luis Gonzalez ◽  
Benjamin E. Botsford ◽  
Tamara L. Lenis ◽  
...  

Purpose: This work aims to evaluate the clinical utility and feasibility of a novel scanning laser ophthalmoscope-based navigated ultra-widefield swept-source optical coherence tomography (UWF SS-OCT) imaging system. Methods: A retrospective, single-center, consecutive case series evaluated patients between September 2019 and October 2020 with UWF SS-OCT (modified Optos P200TxE, Optos PLC) as part of routine retinal care. The logistics of image acquisition, interpretability of images captured, nature of the peripheral abnormality, and clinical utility in management decisions were recorded. Results: Eighty-two eyes from 72 patients were included. Patients were aged 59.4 ± 17.1 years (range, 8-87 years). During imaging, 4.4 series of images were obtained in 4.1 minutes, with 86.4% of the image series deemed to be diagnostic of the peripheral pathology on blinded image review. The most common pathologic findings were chorioretinal scars (18 eyes). In 31 (38%) eyes, these images were meaningful in supporting clinical decision-making with definitive findings. Diagnoses imaged included retinal detachment combined with retinoschisis, retinal hole with overlying vitreous traction and subretinal fluid, vitreous inflammation overlying a peripheral scar, Coats disease, and peripheral retinal traction in sickle cell retinopathy. Conclusions: Navigated UWF SS-OCT imaging was clinically practical and provided high-quality characterization of peripheral retinal lesions for all eyes. Images directly contributed to management plans, including laser, injection or surgical treatment, for a clinically meaningful set of patients (38%). Future studies are needed to further assess the value of this imaging modality and its role in diagnosing, monitoring, and treating peripheral lesions.


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

2020 ◽  
pp. 1-9
Author(s):  
Sabrina Bergeron ◽  
Bryan Arthurs ◽  
Debra-Meghan Sanft ◽  
Christina Mastromonaco ◽  
Miguel N. Burnier Jr.

<b><i>Introduction:</i></b> Optical coherence tomography (OCT) imaging has been used as a diagnostic tool for retinal disease for several years, and OCT apparatuses are becoming increasingly powerful. However, OCT has yet to reach its full potential in ophthalmology clinics. Alike retinal layers, it has been shown that OCT is able to generate cross-sectional images of the skin and allows visualization of skin lesions in a histopathology-like manner. <b><i>Objective:</i></b> We aim to validate OCT as an imaging modality for peri-ocular skin cancer. Through a series of cases, we highlight findings for 3 common eyelid malignancies: basal cell carcinoma, squamous cell carcinoma and sebaceous carcinoma. We propose an OCT image-based signature for basal cell carcinoma. <b><i>Methods:</i></b> This is a prospective study. Fifty-eight lesions suspicious of malignancy from 57 patients were subjected to OCT imaging prior to the surgical excision of the lesion. OCT images were analysed and scored according to previously identified OCT features. Eight representative examples are presented, highlighting the OCT patterns for each malignancy side by side to its corresponding histopathological sections. <b><i>Results:</i></b> Out of the 58 lesions analysed, 53 were malignant. A loss of the dermal-epidermal junction is observed in all malignant lesions. A strong link is observed between the presence of subepithelial hyporeflective nests on OCT and the diagnosis of basal cell carcinoma (present in 83% of cases). Conversely, lesions of epithelial origin such as squamous cell carcinoma are most often represented on OCT by acanthosis. Two supplementary cases, one basal cell carcinoma and one sebaceous carcinoma, are provided to illustrate how OCT imaging is a valuable tool in cases where clinical observations may be unusual. <b><i>Conclusions:</i></b> We provide evidence supporting the use of OCT for the evaluation of peri-ocular cancers. OCT enables visualization of the skin layers in vivo, before biopsy. Our results show that certain OCT features can contribute to include or exclude a diagnosis of basal cell carcinoma. By integrating this non-invasive imaging methodology into the routine assessment of peri-ocular skin lesions, especially in health care centres where access to specialists is limited, OCT imaging can increase clinical precision, reduce delays in patient referral and enhance patient care.


2021 ◽  
pp. 159101992110034
Author(s):  
Andre Monteiro ◽  
Demetrius K Lopes ◽  
Amin Aghaebrahim ◽  
Ricardo Hanel

Purpose Flow-diverters have revolutionized the endovascular treatment of intracranial aneurysms, offering a durable solution to aneurysms with high recurrence rates after conventional stent-assisted coiling. Events that occur after treatment with flow-diversion, such as in-stent stenosis (ISS) are not well understood and require further assessment. After assessing an animal model with Optical Coherence Tomography (OCT), we propose a concept that could explain the mechanism causing reversible ISS after treatment of intracranial aneurysms with flow-diverters. Methods Six Pipeline Flex embolization devices (PED-Flex), six PED with Shield technology (PED-Shield), and four Solitaire AB devices were implanted in the carotid arteries (two stents per vessel) of four pigs. Intravascular optical coherence tomography (OCT) and digital subtraction angiography (DSA) images obtained on day 21 were compared to histological specimens. Results A case of ISS in a PED-Flex device was assessed with OCT imaging. Neointima with asymmetrical topography completely covering the PED struts was observed. Histological preparations of the stenotic area demonstrated thrombus on the surface of device struts, covered by neointima. Conclusion This study provides a plausible concept for reversible ISS in flow-diverters. Based on an observation of a previous experiment, we propose that similar cases of ISS are related to thrombus presence underneath endothelization, but further experiments focused on this phenomenon are needed. Optical Coherence Tomography will be useful tool when available for clinical use.


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