scholarly journals Imaging Modalities Employed in Diabetic Retinopathy Screening: A Review and Meta-Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1802
Author(s):  
Piotr Kanclerz ◽  
Raimo Tuuminen ◽  
Ramin Khoramnia
Keyword(s):  
Diabetic Retinopathy ◽  
Failure Rate ◽  
Meta Analysis ◽  
Imaging Modalities ◽  
Fundus Photography ◽  
Technical Failure ◽  
Diabetic Retinopathy Screening ◽  
Field Imaging ◽  
Ultrawide Field Imaging ◽  
Retinopathy Screening

Introduction: Urbanization has caused dramatic changes in lifestyle, and these rapid transitions have led to an increased risk of noncommunicable diseases, such as type 2 diabetes. In terms of cost-effectiveness, screening for diabetic retinopathy is a critical aspect in diabetes management. The aim of this study was to review the imaging modalities employed for retinal examination in diabetic retinopathy screening. Methods: The PubMed and Web of Science databases were the main sources used to investigate the medical literature. An extensive search was performed to identify relevant articles concerning “imaging”, “diabetic retinopathy” and “screening” up to 1 June 2021. Imaging techniques were divided into the following: (i) mydriatic fundus photography, (ii) non-mydriatic fundus photography, (iii) smartphone-based imaging, and (iv) ultrawide-field imaging. A meta-analysis was performed to analyze the performance and technical failure rate of each method. Results: The technical failure rates for mydriatic and non-mydriatic digital fundus photography, smartphone-based and ultrawide-field imaging were 3.4% (95% CI: 2.3–4.6%), 12.1% (95% CI: 5.4–18.7%), 5.3% (95% CI: 1.5–9.0%) and 2.2% (95% CI: 0.3–4.0%), respectively. The rate was significantly different between all analyzed techniques (p < 0.001), and the overall failure rate was 6.6% (4.9–8.3%; I2 = 97.2%). The publication bias factor for smartphone-based imaging was significantly higher than for mydriatic digital fundus photography and non-mydriatic digital fundus photography (b = −8.61, b = −2.59 and b = −7.03, respectively; p < 0.001). Ultrawide-field imaging studies were excluded from the final sensitivity/specificity analysis, as the total number of patients included was too small. Conclusions: Regardless of the type of the device used, retinal photographs should be taken on eyes with dilated pupils, unless contraindicated, as this setting decreases the rate of ungradable images. Smartphone-based and ultrawide-field imaging may become potential alternative methods for optimized DR screening; however, there is not yet enough evidence for these techniques to displace mydriatic fundus photography.

scholarly journals Widefield imaging of retinal and choroidal tumors

2019 ◽  
Vol 5 (S1) ◽  
Author(s):  
Natalia F. Callaway ◽  
Prithvi Mruthyunjaya
Keyword(s):  
Fundus Autofluorescence ◽  
Imaging Modalities ◽  
Fundus Photography ◽  
Wide Field ◽  
Indocyanine Angiography ◽  
Relationship Of ◽  
The Relationship ◽  
Field Imaging ◽  
Wide Field Imaging ◽  
Sd Oct

Abstract Background Wide-field imaging plays an increasingly important role in ocular oncology clinics. The purpose of this review is to describe the commonly used wide-field imaging devices and review conditions seen in ocular oncology clinic that underwent wide-field imaging as part of the multimodal evaluation. Summary of review Wide-field or wide-angle imaging is defined as greater than 50° field of view. Modern devices can reach far beyond this reporting fields of view up to 267°, when utilizing montage features, with increasingly impressive resolution. Wide-field imaging modalities include fundus photography, fluorescein angiography (FA), fundus autofluorescence (FAF), indocyanine angiography (ICG), spectral domain optical coherence tomography (SD-OCT), and recently wide-field OCT Angiography (OCTA). These imaging modalities are increasingly prevalent in practice. The wide-field systems include laser, optical, and lens based systems that are contact or non-contact lens systems each with its own benefits and drawbacks. The purpose of this review is to discuss commonly used wide-field imaging modalities for retinal and choroidal tumors and demonstrate the use of various widefield imaging modalities in select ocular oncology cases. Conclusions Clinical examination remains the gold standard for the evaluation of choroidal and retinal tumors. Wide-field imaging plays an important role in ocular oncology for initial documentation, surgical planning, determining the relationship of the tumor to adjacent ocular structures, following tumor size after treatment, and monitoring for recurrence.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

Imaging Modalities for the Study of the Temporal Bone

1988 ◽  
Vol 21 (2) ◽  
pp. 219-244
Author(s):  
Anton N. Hasso ◽  
John A. Ledington
Keyword(s):  
Temporal Bone ◽  
Imaging Modalities

State-of-the-art pulmonary arterial imaging – Part 2

VASA ◽  
2018 ◽  
Vol 47 (5) ◽  
pp. 361-375 ◽  
Author(s):  
Harold Goerne ◽  
Abhishek Chaturvedi ◽  
Sasan Partovi ◽  
Prabhakar Rajiah
Keyword(s):  
Pulmonary Artery ◽  
State Of The Art ◽  
Therapy Monitoring ◽  
Pulmonary Arteries ◽  
Imaging Modalities ◽  
Cross Sectional ◽  
Multiple Imaging ◽  
Cross Sectional Imaging ◽  
Pulmonary Arterial ◽  
Arterial Imaging

Abstract. Although pulmonary embolism is the most common abnormality of the pulmonary artery, there is a broad spectrum of other congenital and acquired pulmonary arterial abnormalities. Multiple imaging modalities are now available to evaluate these abnormalities of the pulmonary arteries. CT and MRI are the most commonly used cross-sectional imaging modalities that provide comprehensive information on several aspects of these abnormalities, including morphology, function, risk-stratification and therapy-monitoring. In this article, we review the role of state-of-the-art pulmonary arterial imaging in the evaluation of non-thromboembolic disorders of pulmonary artery.

State-of-the-art pulmonary arterial imaging – Part 1

VASA ◽  
2018 ◽  
Vol 47 (5) ◽  
pp. 345-359 ◽  
Author(s):  
Yuki Tanabe ◽  
Luis Landeras ◽  
Abed Ghandour ◽  
Sasan Partovi ◽  
Prabhakar Rajiah
Keyword(s):  
State Of The Art ◽  
Pulmonary Arteries ◽  
Pulmonary Angiography ◽  
Imaging Modalities ◽  
Nuclear Medicine Imaging ◽  
Multiple State ◽  
Pulmonary Arterial ◽  
Magnetic Resonance Imaging Mri ◽  
Acquired Abnormalities ◽  
Arterial Imaging

Abstract. The pulmonary arteries are affected by a variety of congenital and acquired abnormalities. Multiple state-of-the art imaging modalities are available to evaluate these pulmonary arterial abnormalities, including computed tomography (CT), magnetic resonance imaging (MRI), echocardiography, nuclear medicine imaging and catheter pulmonary angiography. In part one of this two-part series on state-of-the art pulmonary arterial imaging, we review these imaging modalities, focusing particularly on CT and MRI. We also review the utility of these imaging modalities in the evaluation of pulmonary thromboembolism.

Biliary papillomatosis and new ultrasound imaging modalities

2012 ◽  
Vol 25 (01) ◽  
Author(s):  
XW Cui ◽  
A Ignee ◽  
B Braden ◽  
M Woenckhaus ◽  
CF Dietrich
Keyword(s):  
Ultrasound Imaging ◽  
Imaging Modalities ◽  
Biliary Papillomatosis

Stents for the Treatment of Aortic Aneurysms

1999 ◽  
Vol 82 (S 01) ◽  
pp. 171-175 ◽  
Author(s):  
D. Ebert ◽  
M. Langer ◽  
P. Uhrmeister
Keyword(s):  
Endovascular Treatment ◽  
Endovascular Repair ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Imaging Modalities ◽  
Exclusion Criteria ◽  
Multicenter Studies ◽  
Abdominal Aortic ◽  
First Results

SummaryThe endovascular treatment of abdominal aortic aneurysms has generated a great deal of interest since the early 1990s, and many different devices are currently available. The procedure of endovascular repair has been evaluated in many institutions and the different devices are compared. The first results were encouraging, but complications like endoleak, dislocation or thrombosis of the graft occurred. By the available devices the stent application is only promising, if the known exclusion criteria are strictly respected. Therefore a careful preinterventional assessment of the patient by different imaging modalities is necessary. As the available results up to now are preliminary and the durability of the devices has to be controlled, multicenter studies are required to improve the devices and observe their long- term success in the exclusion of abdominal aortic aneurysms.

Sign in / Sign up

Export Citation Format

Share Document