scholarly journals Crystalline lens imaging with a slit-scanning system

2011 ◽  
pp. 93-96 ◽  
Keyword(s):  
Crystalline Lens ◽  
Scanning System ◽  
Slit Scanning

scholarly journals Crystalline lens imaging during accommodation with a slit-scanning tomography system: preliminary results

2020 ◽  
Vol 238 ◽  
pp. 12015
Author(s):  
Jessica Gomes ◽  
Sandra Franco
Keyword(s):  
Crystalline Lens ◽  
Experimental Results ◽  
Wavefront Aberrations ◽  
Preliminary Results ◽  
Ocular Accommodation ◽  
Tomography System ◽  
Slit Scanning

A slit-scanning tomography system previously developed in the Centre of Physics of University of Minho allows to capture images of the eye and posteriorly calculus of the biometric (thickness and curvature) and optical (wavefront aberrations) properties of the corneal and crystalline lens surfaces. It is intended to optimise the system for an accurate computing of these properties of the crystalline lens in the relaxed state and during ocular accommodation. In this study, preliminary experimental results of the crystalline lens imaging of a subject during accommodation are presented.

scholarly journals Detection of Urinary Stones at Reduced Radiation Exposure: A Phantom Study Comparing Computed Radiography and a Low-Dose Digital Radiography Linear Slit Scanning System

2009 ◽  
Vol 192 (6) ◽  
pp. W271-W274 ◽  
Author(s):  
Zsolt Szucs-Farkas ◽  
Dev P. Chakraborty ◽  
Harriet C. Thoeny ◽  
Christos Loupatatzis ◽  
Peter Vock ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Digital Radiography ◽  
Low Dose ◽  
Computed Radiography ◽  
Phantom Study ◽  
Urinary Stones ◽  
Scanning System ◽  
Slit Scanning

scholarly journals Clinical boundary conditions for grating-based differential phase-contrast mammography

2014 ◽  
Vol 372 (2010) ◽  
pp. 20130033 ◽  
Author(s):  
Ewald Roessl ◽  
Heiner Daerr ◽  
Thomas Koehler ◽  
Gerhard Martens ◽  
Udo van Stevendaal
Keyword(s):  
Boundary Conditions ◽  
Phase Contrast ◽  
Clinical Aspects ◽  
Scanning System ◽  
Contrast Imaging ◽  
X Ray ◽  
Differential Phase ◽  
Advantages And Disadvantages ◽  
Differential Phase Contrast ◽  
Slit Scanning

Research in grating-based differential phase-contrast imaging (DPCI) has gained increasing momentum in the past couple of years. The first results on the potential clinical benefits of the technique for X-ray mammography are becoming available and indicate improvements in terms of general image quality, the delineation of lesions versus the background tissue and the visibility of microcalcifications. In this paper, we investigate some aspects related to the technical feasibility of DPCI for human X-ray mammography. After a short introduction to state-of-the-art full-field digital mammography in terms of technical aspects as well as clinical aspects, we put together boundary conditions for DPCI. We then discuss the implications for system design in a comparative manner for systems with two-dimensional detectors versus slit-scanning systems, stating advantages and disadvantages of the two designs. Finally, focusing on a slit-scanning system, we outline a possible concept for phase acquisition.

Tandem scanning confocal light microscopy as compared with x-ray diffraction for characterizing the behavior of clays in fluid-saturated petroleum reservoir rock

1989 ◽  
Vol 47 ◽  
pp. 148-149
Author(s):  
C.J. Stuart ◽  
B.E. Viani ◽  
J. Walker ◽  
T.H. Levesque
Keyword(s):  
Light Microscopy ◽  
Image Plane ◽  
Reservoir Rock ◽  
Depth Of Field ◽  
Objective Lens ◽  
Scanning System ◽  
Light Sources ◽  
Petroleum Reservoir ◽  
Image Recording ◽  
Scan Speed

Many techniques of imaging used to characterize petroleum reservoir rocks are applied to dehydrated specimens. In order to directly study behavior of fines in reservoir rock at conditions similar to those found in-situ these materials need to be characterized in a fluid saturated state.Standard light microscopy can be used on wet specimens but depth of field and focus cannot be obtained; by using the Tandem Scanning Confocal Microscope (TSM) images can be produced from thin focused layers with high contrast and resolution. Optical sectioning and extended focus images are then produced with the microscope. The TSM uses reflected light, bulk specimens, and wet samples as opposed to thin section analysis used in standard light microscopy. The TSM also has additional advantages: the high scan speed, the ability to use a variety of light sources to produce real color images, and the simple, small size scanning system. The TSM has frame rates in excess of normal TV rates with many more lines of resolution. This is accomplished by incorporating a method of parallel image scanning and detection. The parallel scanning in the TSM is accomplished by means of multiple apertures in a disk which is positioned in the intermediate image plane of the objective lens. Thousands of apertures are distributed in an annulus, so that as the disk is spun, the specimen is illuminated simultaneously by a large number of scanning beams with uniform illumination. The high frame speeds greatly simplify the task of image recording since any of the normally used devices such as photographic cameras, normal or low light TV cameras, VCR or optical disks can be used without modification. Any frame store device compatible with a standard TV camera may be used to digitize TSM images.

X-ray mapping without STEM

1994 ◽  
Vol 52 ◽  
pp. 508-509
Author(s):  
Judith M. Brock ◽  
Max T. Otten
Keyword(s):  
Life Science ◽  
Materials Science ◽  
Chemical Elements ◽  
Full Description ◽  
Scanning System ◽  
Elemental Distribution ◽  
X Ray ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Made In

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.

Extrascleral Filling Using Endoillumination the First Experiencethe

2020 ◽  
pp. 43-49
Author(s):  
V.Y. Markevich ◽  
◽  
T.A. Imshenetskaya ◽  
O.A. Yarmak ◽  
◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Retinal Detachment ◽  
Rhegmatogenous Retinal Detachment ◽  
Silicone Oil ◽  
Subretinal Fluid ◽  
Crystalline Lens ◽  
Vitreous Cavity ◽  
Macular Area ◽  
General Group ◽  
Anatomical Outcome

Purpose. To study the effectiveness of extrascleral filling (ESF) using endoillumination in the surgical treatment of patients with primary rhegmatogenous retinal detachment (RRD). Material and methods. The material for the study was the data of a comprehensive clinical examination and surgical treatment by ESF method using endoillumination in 17 patients (17 eyes) with RRD. In 7 cases (41%), the macular area was involved in the detachment process. In 5 cases (29.4%), local scleral filling was performed. In the remaining 12 cases (70.6%), the local ESF was supplemented with a circling silicone element. Surgical intervention was supplemented by transscleral drainage of subretinal fluid (SRF) in 10 cases (59%) and pneumatic retinopexy with SF6 gas 50% in 8 cases (48%). Results. In the general group of patients, best corrected visual acuity (BCVA) increased from 0.35 to 0.46. In the subgroup of patients with a detached macular area, the positive dynamics is more pronounced, BCVA increased from 0.1 to 0.28. The progression of proliferative vitreoretinopathy caused the recurrence of retinal detachment in two patients (11.8%). Recurrences were diagnosed after 3 and 5 months, respectively. In both cases, a vitrectomy with tamponade of the vitreous cavity with silicone oil 5000 Cst was performed. The percentage of successful anatomical outcome after the first operation in our study was 82%. The percentage of successful achievement of the final anatomical result was 94%. In two cases, additional injection of SF6 gas into the vitreous cavity was required. Conclusion. This type of surgical treatment is an effective method of surgical treatment of patients with RRD. In our study, the successful anatomical outcome after the first operation was recorded in 82% of patients, which correlates with the data of the authors who also used this method (83–92%). Surgeons who performed surgical treatment using this technique in our study note improved workplace ergonomics when visualizing the fundus using an operating microscope and endoillumination compared with indirect ophthalmoscopy. Other teams of authors came to this conclusion as well. In our study, there were no complications associated with the introduction of a light pipe into the vitreous cavity (iatrogenic crystalline lens injury, endophthalmitis), which indicates the safety of this type of surgical treatment.

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