Diverging beam transmit through limited aperture: A method to reduce ultrasound system complexity and yet obtain better image quality at higher frame rates

Ultrasonics ◽  
2019 ◽  
Vol 91 ◽  
pp. 150-160 ◽  
Author(s):  
B. Lokesh ◽  
Arun K. Thittai
Keyword(s):  
Image Quality ◽  
System Complexity ◽  
Ultrasound System

Inexpensive, realtime tele-ultrasound using a commercial, web-based video streaming device

2012 ◽  
Vol 18 (4) ◽  
pp. 185-188 ◽  
Author(s):  
Yannis M Paulus ◽  
Noel P Thompson
Keyword(s):  
Image Quality ◽  
Video Streaming ◽  
Delay Time ◽  
Qualitative Assessment ◽  
Web Based ◽  
Grey Scale ◽  
Standard Resolution ◽  
Ultrasound System

We have devised an inexpensive, web-based tele-ultrasound system using commercially-available video streaming equipment. We examined the spatial and grey scale resolution, and the delay time of the system. The receiving PC was tested at various distances from the transmitting site, from 3.2 km to 4828 km. Standard resolution targets and echocardiography movie strips recorded on DVDs were used to assess the image quality. A qualitative assessment was made by an expert sonographer. As the distance between the transmitter and the receiver increased, the scan smoothness decreased and the delay increased. At a distance of 3.2 km the delay was 2–3 s, and at 4828 km it was 10–15 s. The delay was short enough to allow realtime guidance of the scanning technician by telephone. The system allows inexpensive, readily available, realtime tele-ultrasonography.

scholarly journals EchoScopy in scanning abdominal diseases; a prospective single center study

2019 ◽  
Vol 21 (1) ◽  
pp. 8 ◽  
Author(s):  
Ana Paula Barreiros ◽  
Yi Dong ◽  
Andre Ignee ◽  
Daniel Wastl ◽  
Christoph F. Dietrich
Keyword(s):  
Image Quality ◽  
Handheld Devices ◽  
Focal Lesion ◽  
European Federation ◽  
Pathological Findings ◽  
Focal Lesions ◽  
Handheld Ultrasound ◽  
Ultrasound System ◽  
Dual Probe

Background and aims: The introduction of a new type of small handheld ultrasound device brings greater portability and affordability in a different setting. The basic ultrasound approach with these handheld devices has been defined by European Federation of Societies of Ultrasound in Medicine and Biology (EFSUMB) as “EchoScopy”. The current study aimed to assess the image quality, indications and limitations of a portable pocket “EchoScopy” performed first compared with a high-end ultrasound system (second) in abdominal diseases.Material and methods: Three hundred consecutive patients (158 males and 142 females, age 55±19 [18-96]) years) were included. The ultrasound examinations were performed firstly by an EchoScope (Vscan™ Dual Probe) and secondly with a high-end ultrasound system (HEUS, GE Logiq E9). Compared with the always excellent image quality using HEUS, the image quality of the EchoScope was graded as good, sufficient or non-sufficient.Results: Out of all 300 patients, 221 had focal lesions, 31 patients were found with diffuse pathological findings, 20 with ascites, 25 after liver puncture and 45 without any pathological findings. The image quality of the pocket device was considered as being good or sufficient to delineate the pathology in 265/300 (88%). The detection rate of the EchoScope for abdominal focal lesion was 172/221 (78%). The higher frequency of the Dual Probe was helpful in 35/300 (12%).Conclusions: EchoScopy has proven to display sufficient image quality to answer specific questions, e.g., detection of ascites, splenomegaly, bile duct enlargement, hydronephrosis and other pathological findings which can be judged by “yes/no”.

Filter-Based Synthetic Transmit and Receive Focusing

2001 ◽  
Vol 23 (2) ◽  
pp. 73-89 ◽  
Author(s):  
Meng-Lin Li ◽  
Pai-Chi Li
Keyword(s):  
Image Quality ◽  
Ultrasonic Imaging ◽  
Imaging Systems ◽  
System Complexity ◽  
Quality Degradation ◽  
Filtering Technique ◽  
Focal Zone

Most diagnostic ultrasonic imaging systems perform fixed focusing on transmit and dynamic focusing on receive. Such systems suffer from image quality degradation at depths away from the transmit focal zone. Several dynamic transmit focusing techniques have been previously investigated. Among them, a filter-based, retrospective focusing technique was proposed to increase the length of the transmit focal zone. In this paper, the filter-based technique is extended from dynamic receive focusing to fixed receive focusing. It is shown that the filtering technique with fixed receive focusing can achieve an image quality similar to that of dynamic receive focusing with filtering. The performance of the proposed approach is verified using real ultrasound data. It is shown that the proposed approach with fixed receive focusing requires a longer filter than that with dynamic receive focusing. Nonetheless, system complexity is greatly reduced with synthetic transmit and receive focusing because the dynamic receive focusing circuit is no longer needed.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

An Environmental Wet Cell For High Voltage Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 18-19
Author(s):  
N.J. Tighe ◽  
H.M. Flower ◽  
P.R. Swann
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Image Quality ◽  
Inelastic Scattering ◽  
High Voltage ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Environmental Cell ◽  
Water Saturated ◽  
High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

The influence of confocal microscope design on imaging performance

1993 ◽  
Vol 51 ◽  
pp. 144-145
Author(s):  
C J R Sheppard
Keyword(s):  
Image Quality ◽  
Fluorescence Imaging ◽  
Confocal Microscope ◽  
Industrial Applications ◽  
Three Dimensions ◽  
Design Parameters ◽  
Weak Signals ◽  
Size And Shape ◽  
Imaging Performance ◽  
Fundamental Limitation

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.

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