摘要:

In recent years the application of computers to chest radiography has resulted in a wide variety of innovative research. Major research efforts have resulted in the development of new types of x-ray detectors, such as storage phosphor technology, for use with computers. Storage phosphor imaging is one of the most promising new techniques, and almost 100 systems have been installed worldwide. Radiologists are quickly evaluating the image quality provided by this new detector system, which has the potential to improve image quality. It has wide latitude and is coupled with a computer to perform image processing. Another promising technology, originally studied in the form of scan equalization radiography, is now commercially available in the form of advanced multiple-beam equalization radiography. This film technique uses computers to modulate the x-ray exposure to take maximum advantage of the imaging capabilities of radiographic film. Digital solid-state detectors have been studied in conjunction with computerized image enhancement systems. These currently show improvement in nodule detection and quantification of the calcium content of a lesion. Application of large image intensifiers to a digital image system is being studied, but there are currently limitations on spatial resolution.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Thoracic imaging constitutes more than one-third of all medical imaging performed in the United States. Despite the substantial impact of computer technology in other areas of imaging, conventional film-screen acquisition systems still provide the bulk of projectional chest radiography. The successful implementation of digital technology in thoracic imaging requires that the standards of current film-screen methods for both diagnostic accuracy and efficient data management be preserved. This article addresses the technical and clinical aspects of film digitization and storage phosphor technology, which are the two digital acquisition systems in widest application. Scanned projection radiography, which may now be applied to computed radiography systems, is also discussed. Finally, some of the issues surrounding the implementation of picture archiving and communication systems for thoracic imaging are addressed.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

This article describes the current status and potential applications of high-resolution storage phosphor for imaging of the chest. Digital imaging that uses storage phosphor technology is easily adaptable to existing x-ray-generating equipment and can also be used with mobile equipment. The wide latitude of the storage phosphor technique permits satisfactory imaging in situations in which exposure factors cannot be accurately estimated or easily controlled. Early experience with an experimental Kodak high-resolution (4K x 4K) storage phosphor system suggests that standard and portable chest images of excellent quality can be obtained. Many issues must be resolved, however, before digital radiology with a storage phosphor can be advocated as being preferable to conventional film-screen systems. These issues, which include display modalities (film or television monitor), resolution requirements, and the effects of image processing, can only be resolved by further large-scale accuracy studies. The change to a digital imaging system will involve major expenditures for equipment and computers. Cost will be related largely to the level of spatial resolution required for primary radiographic diagnosis.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughput of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A storage phosphor digital imaging system has been used to perform virtually all of an increasing number of mobile (portable) projectional roentgenographic examinations in a busy hospital. Approximately 130 such studies are done per day, of which about 110 are chest examinations. The processing unit suffices to keep pace with peak activity in the radiology department. This technique has decreased the repeat rate for portable anteroposterior chest radiographic examinations from 4.5% to less than 1% and has resulted in an even more dramatic reduction in the rate for lateral or decubitus chest examinations as well as for studies of the abdomen and those done in the operating room. The diagnostic accuracy and confidence level achieved in interpreting the complementary pair of digital images has been equivalent to or has exceeded that obtained with conventional mobile analog film-screen radiographs.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A digital radiography system based on reusable, photostimulable phosphor technology was evaluated in approximately 3500 portable chest radiographs of patients in an intensive care unit. The system functioned well in this application. No major problems were encountered in the visualization of tubes or catheters or in the detection of pneumotboraces. Assessment of fluid volume status or the presence of small pleural effusions, especially when these were bilateral, was initially somewhat difficult but became easier as investigators became familiar with the system. Radiologists were quicker than nonradiologists to accept the minimized two-on-one display format. Critical evaluation of the overall performance of digital systems such as this one is needed for a better definition of the system's strengths and weaknesses. Specifically, statistical analyses of the ability to detect disease states such as pneumothoraces, interstitial lung disease, lung nodules, and pleural abnormalities need to be performed.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Currently the radiographic determination of the benign or malignant nature of solitary pulmonary nodules relies on growth characteristics determined by comparison radiographs or the detection of calcification in the nodule with either low-peak kilovoltage fluoroscopy or CT of the chest. An alternative approach is analysis of the optical densities within the nodules by means of digital radiography. Two techniques have been described: histogram analysis of chest radiographs digitized with a laser scanner and dual-energy digital radiography. Although both techniques remain experimental, they offer a potential advantage over CT in that a single radiographic exposure is sufficient, thus decreasing the radiation dose to the patient and providing the patient with a less complex work-up.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The present study was undertaken to examine experimentally and clinically whether a 100-mm roll-film digitizer and image processing device could preserve or increase the diagnostic accuracy of 100-mm roll films used in the mass screening of patients for lung cancer and provide picture archives of high enough image quality to replace the original films. The quality of the processed digitized CRT image was found to be only slightly less than that of the original films. There was only a slight decrease in diagnostic accuracy, and the system was judged to be potentially useful as a miniature picture archiving and reference system.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Digital radiography offers several important advantages over conventional systems, including abilities for image manipulation, transmission, and storage. In the long term, however, the unique ability to apply artificial intelligence techniques for automated detection and quantitation of disease may have an even greater impact on radio-logic practice. Although CAD is still in its infancy, the results of several recent studies clearly indicate a major potential for the future. The concept of using computers to analyze medical images is not new, but recent advances in computer technology together with progress in implementing practical digital radiography systems have stimulated research efforts in this exciting field. Several facets of CAD are presently being developed at the University of Chicago and elsewhere for application in chest radiology as well as in mammography and vascular imaging. To date, investigators have focused on a limited number of subjects that have been, by their nature, particularly suitable for computer analysis. There is no aspect of radiologic diagnosis that could not potentially benefit from this approach, however. The ultimate goal of these endeavors is to provide a system for comprehensive automated image analysis, the results of which could be accepted or modified at the discretion of the radiologist.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A multimedia radiologic communication system has been developed that achieves the system design goal of providing a clinical communication service that is an efficient improvement over present methods of communication. The system allows users to access, through a workstation, digitized radiographic images, voice reports, and other patient data. Physicians can consult with each other while simultaneously accessing this information through a shared visual workspace, even though they are in different places. The system was designed by a multidisciplinary team including radiologists, clinicians, engineers, user-interface specialists, and psychologists from hospital, university, and research settings in an effort to maximize system performance and clinical utility.

ISSN:0883-5993    

出版商:OVID    

年代:1990

数据来源: OVID