The Full-Scale Pacs Archive

1996 ◽  
Vol 37 (3P2) ◽  
pp. 838-846 ◽  
Author(s):  
S. A. Nissen-Meyer ◽  
U. Fink ◽  
M. Pleier ◽  
C. Becker
Keyword(s):  
Digital Image ◽  
Conventional Radiography ◽  
Full Scale ◽  
Model Calculations ◽  
Analog To Digital ◽  
Alternative Technologies ◽  
Transition Strategy ◽  
Hospital Operations ◽  
Picture Archiving And Communication ◽  
Image Archives

Purpose: Increasing percentages of digital modalities in radiology, in particular of digital image acquisition in conventional radiography, call for digital reporting, communication, and archiving techniques. These techniques are prerequisites for the “filmless” hospital. The first 2 have been covered extensively in the literature and by vendors. However, as regards online digital image archives there are still no satisfactory concepts available in the medical field. The present paper puts forward some suggestions as to how this situation could be improved. Material and Methods: Analyses of radiology operations consider the prevailing PACS (picture archiving and communication system) archive concepts that use optical discs to be too small, too slow and too cumbersome to manage and therefore unable to function as comprehensive image archives for filmless hospitals. We suggest borrowing and adapting the well tested archive technologies from space research and the oil and broadcasting industries which have much higher capacities and speeds and better software interfacing possibilities. With such technologies the needs of filmless hospital operations can be met. Results: A feasible concept for a transition strategy from conventional analog to digital archives is presented. Model calculations of the necessary investments and potential savings, including generous placement of viewing stations in the entire hospital, indicate amortization periods of 3.8–4.8 years. Conclusion: Alternative technologies for digital image archives already today make full-scale PACS for filmless hospitals technologically and conceptually feasible and financially mandatory.

Imagines fictae: Digital image archives in historical research

1998 ◽  
Vol 10 (1-3) ◽  
pp. 109-111 ◽  
Author(s):  
Gerhard Jaritz
Keyword(s):  
Image Analysis ◽  
Digital Image ◽  
Digital Image Analysis ◽  
Secondary Analysis ◽  
Historical Research ◽  
The Past ◽  
Historical Images ◽  
Historical Archives ◽  
The Creation ◽  
Image Archives

Historical images contain a variety of signs and meanings. The latter have influenced perception and response decisively, in the past as well as today. Methods and possibilities of computer-supported image analysis in context, and particularly of digital image analysis have started to support recent research-efforts considerably. The creation and organisation of digitised historical archives seem to have become particularly important for any kind of studies of the contents and messages of pictorial sources. This creation and organisation of image archives, and the analysis of the contents of such archives mainly imply digitisation and documentation, making catalogues and codebooks available, the linking and binding of images and their details, encoding, segmentation, sub-segmentation and archiving the image segments, creating and keeping up contexts. They make comparative primary and secondary analysis possible. Fruitful co-operation and exchange of skills are necessary. The ‘culture of images’has come up to other levels; history and its images are about to reach new and very promising dimensions.

Costs of plain-film radiography in a partially digitized radiology department

1998 ◽  
Vol 39 (2) ◽  
pp. 200-207
Author(s):  
J. Alanen ◽  
L. Keski-Nisula ◽  
J. Laurila ◽  
I. Suramo ◽  
C.-G. Standertskjöld-Nordenstam ◽  
...  
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Digital Image ◽  
Transition Period ◽  
Computed Radiography ◽  
Plain Film ◽  
Conventional Radiography ◽  
Radiology Department ◽  
Plain Film Radiography ◽  
Conventional Film

Purpose: the aim of the study was to analyse the costs of computed radiography (CR) as part of a small picture archiving and communication system (mini-PACS), and to compare these costs with those of conventional analogue radiography using activity-based accounting (ABC) Material and Methods: the study was conducted at the Central Hospital of Vaasa where in 1993 the Radiology Department acquired a mini-PACS with a CR reader, a chest CR unit, and a CT unit as digital image processing modalities. of altogether 34140 plain-film examinations, 3/4 were made with CR and stored mostly on film, and 1/4 were made with conventional analogue radiography. the costs and activities of these two modes were analysed by means of the ABC method which identifies and allocates indirect costs in radiological procedures Results: the costs of CR imaging were 9% higher than those of conventional radiography. the costs of the chest CR unit were equal to those of conventional radiography. the difference was due to higher investment costs in digital image processing. the time gained from a reduction in the number of retakes did not shorten the time spent by patients in the examination room, and its effect on film costs was minimal Conclusion: in planning the step-by-step transition of conventional film-based analogue radiography to fully digitized radiography, it should be noted that films are still used in the transition period and that this is associated with higher costs than in the previous system of conventional analogue plain-film imaging

Recent Progress in Development of Ductile Fracture Arrest Methodology Based on CTOA: Test Standard, Transferability and Methodology

2020 ◽  
Author(s):  
S. Xu ◽  
C. Bassindale ◽  
J. Xue ◽  
B. W. Williams ◽  
X. Wang
Keyword(s):  
Crack Velocity ◽  
Damage Mechanics ◽  
Loading Rate ◽  
Test Procedure ◽  
Full Scale ◽  
Correction Factors ◽  
Type Specimens ◽  
Model Calculations ◽  
Resistance Curves ◽  
Fracture Arrest

Abstract Significant progress has been made in development of a new fracture arrest methodology based on a toughness parameter designed to characterize propagation — the crack-tip opening angle (CTOA). A CTOA test procedure using lab-scale DWTT-type specimens has been standardized by ASTM, and recently published experimental work has demonstrated transferability of CTOA from DWTT to full-scale pipe. This paper will present the basic methodology for determination of CTOA using DWTT-type specimens (i.e., ASTM E3039) and other specimens such as modified double-cantilever-beam (MDCB). Recent numerical studies using cohesive zone models (CZM) and others based on damage mechanics will be discussed, including models of full-scale pipe fracture. The effects on CTOA of loading rate, specimen flattening and constraint (bending vs. tension) will be reviewed. The effect on CTOA of loading rate between quasi-static and impact (covering five orders of magnitude) is small or negligible, being within experimental scatter. Observed differences between surface and mid-thickness CTOA values will be discussed. Models of DWTT specimens using damage mechanics have shown that the CTOA for tensile loading is the same at the surface and mid-thickness and equal to the mid-thickness value for bend loading, but that the surface CTOA is significantly larger than the mid-thickness CTOA in bending. Model calculations have revealed the dependence of crack velocity on stress for a given CTOA, enabling construction of fracture resistance curves (pressure required to propagate fracture as a function of crack velocity). These first-principles curves based on CTOA can then be used in the Battelle two-curve model (BTCM) to replace empirical resistance curves based on Charpy absorbed energy (Cv). It has been known for some time that Cv over-represents the propagation resistance for high-strength high-toughness steels, requiring empirical “correction factors” to Cv in the BTCM. Experiments have shown that there is a non-linear correlation between Cv and CTOA, explaining the need for correction factors to Cv and supporting the use of CTOA as a more appropriate propagation toughness.

Sign in / Sign up

Export Citation Format

Share Document