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Biomedical subjects

S B Seshadri

Publications and source records attributed to S B Seshadri.

11 recordsLinked to original sources

High-resolution image workstation for intensive care units.

Despite their potential for improving patient management and decreasing costs, picture archiving and communication systems (PACS) are not being absorbed rapidly into clinical practice because of their technical immaturity and because the cost-effectiveness of the technology has not been established. Workstations and archives need to be significantly improved before they can be useful. This report describes the authors' experiences with a high-resolution image workstation for a medical intensive care unit. The workstation has been designed around a standard computer platform and is equipped with two high-resolution image displays. The user interface stresses speed and simplicity. Image manipulation is simplified by providing empirical preset window and level values. Images are displayed in less than 2 seconds. The workstation also displays radiologic reports as soon as they become available. Future work will focus on using the workstation to improve communication between the physician and the radiologist.

Humans

The impact of PACS on research and education.

Picture Archiving and Communication Systems (PACS) are rapidly evolving and the total digital radiology department may be a reality within the next decade. PACS can have a major impact on the educational and research responsibilities of a medical institution. The possibility of correlating real patient data with existing radiological teaching files opens up numerous possibilities. Multi-institutional research can be strengthened by employing the PACS as the means to the end. This paper discusses the representative examples of how teaching and research can be enhanced with PACS and the technical requirements to achieve the inter-connectivity.

Education, Medical

Software suite for image archiving and retrieval.

The efficient operation of a clinical picture archiving and communication system (PACS) requires a fully functional image archive. The archive should not only be able to store and retrieve images reliably but should also work in concert with software that optimizes the flow of image-related information throughout the PACS. The authors devised a software suite that serves to improve the flow and content of information and the integrity of the data. The software was developed by translating the functions performed by a conventional film library. Types of transactions possible with this system include scheduling, canceling, rescheduling, and prestaging examinations; changing demographic information; merging patient information; and generating reports. The authors believe such a software suite is essential for a clinically useful PACS.

Data Display

The digital imaging workstation.

Picture archiving and communication systems (PACS) are expected to convert film-based radiology into a computer-based digital environment, with associated cost savings and improved physician communication. The digital workstation will be used by physicians to display these "soft-copy" images; however, difficult technical challenges must be met for the workstation to compete successfully with the familiar viewbox. Issues relating to image perception and the impact on physicians' practice must be carefully considered. The spatial and contrast resolutions required vary according to imaging modality, type of procedure, and class of user. Rule-based software allows simple physician interaction and speeds image display. A consensus appears to be emerging concerning the requirements for the PACS workstation. Standards such as the American College of Radiology/National Electrical Manufacturers' Association Digital Imaging and Communication Standard are facilitating commercial applications. Yet much careful study is needed before PACS workstations will be fully integrated into radiology departments.

Computer Systems

Effect of a digital imaging network on physician behavior in an intensive care unit.

This study examined the effect of a medical image management network on the behavior of physicians working in a medial intensive care unit (MICU). For 1 year, 8-week periods during which chest radiographs were digitized and made available to MICU physicians on a digital display console were alternated with 8-week periods during which only film images were available. Clinical efficacy during the periods was compared by measuring the time between completion of imaging examinations and initiation of specific clinical actions such as placement and positioning of tubes. Results indicate that the time required to take some clinical actions decreased with the immediate availability of images on the digital display console. Established procedures for obtaining radiologic information were altered by the digital imaging network. The time at which physicians viewed images changed, and consultations between MICU staff and radiologists decreased. These results indicate that behavior patterns are altered when a new technology replaces an existing one. Optimal use of this technology may require changes in the logistics of clinical practice.

Behavior

Portal radiographs: digital enhancement of contrast.

The quality of low-contrast portal radiographs for radiation therapy can be improved with electronic contrast enhancement. After the image is copied digitally with a laser scanner microdensitometer into 4,096 gray-scale levels (12 bits) and 1,686 X 2,048 pixels, a special software package permits linear, logarithmic, exponential, or sigmoid transformations of the optical density. The precise representation of the portal image can then be interactively adjusted to emphasize the desired anatomy. Clinical examples demonstrate the value of the digital enhancement approach.

Radiographic Image Enhancement

Clinical evaluation of a medical image management system for chest images.

The clinical efficacy and physicians' assessment of a medical image management system (MIMS) for chest images that involved the medical intensive care unit (MICU) and the radiology department were evaluated. A token-passing fiber-optic network was implemented to connect display stations in the MICU and in the chest reading area in the radiology department with a laser film digitizer and an archiving system. To study the clinical efficacy of this system, blocks of 8 weeks during which portable chest images were digitized and immediately made available in the MICU were alternated with blocks of 8 weeks during which film images only were available. Approximately 3000 portable chest examinations were tracked; patients were entered into the study at a rate of 65 per month. Data on time intervals associated with the examination process were collected from MICU physicians, radiologists, radiographers, and film librarians. The time from the completion of an examination to the time an action was taken that was based on radiographic findings showed significant reductions during the digital periods for certain actions. For example, the time to begin drug therapy decreased from a mean of 4.7 hr when films were viewed to a mean of 3.3 hr when digital images were viewed. In conclusion, if prompt action by the MICU physician improves a patient's outcome, a positive effect on patient care will result from the immediate availability of radiographic images.

Computer Systems

Digital chest imaging: comparison of two film image digitizers with a classification task.

A classification test was used to compare the results of digitizing chest radiographs with a linear diode array camera and a laser scanner. The ability of B readers to classify a pneumoconiosis test set from original radiographs and the digitized images was compared. The classification of profusion was impaired when images were digitized with the diode array camera but not when they were digitized with the laser scanner. The impairment found with images digitized with the linear diode array camera was overcome with use of a zoom function at the display station. The size of areas of opacification was overestimated on images from both scanners. Variation between and within observers (kappa approximately equal to 0.6) was consistent over observers and over modalities.

Evaluation Studies as Topic

Design of a medical image management system: a practical cost-effective approach.

The impact of technology and economics is driving radiology departments into a digital era. There have been significant developments in the design of Medical Image Management System components. However, many important design criteria have been neglected, leading to an ineffective end product. This paper will discuss the more important design criteria. The design will be considered from the user's point of view. The implementation of a prototype Medical Image Management System (MIMS) serving a Medical Intensive Care Unit in our Institution will be presented. The structure and very preliminary results of a clinical evaluation will be discussed. Plans to expand the MIMS beyond the Department and the Hospital will also be briefly discussed. The role of the personal computer in the design of a MIMS will be reviewed.

Computer Systems

Clinical experience with PACS at the University of Pennsylvania.

A Picture Archiving and Communication System (PACS) was installed in the Medical Intensive Care Unit of the Hospital of the University of Pennsylvania. For one year, 8 week periods of FILM ONLY usage were alternated with 8 week periods of PACS OR FILM usage. The time interval between obtaining portable chest images and taking image dependent actions decreased when the PACS was used, however, about 40% of the action decisions were made without a radiologist's consultation. Only 5% of action decisions were made without consultation during the FILM ONLY periods. A new clinical study for measuring diagnostic accuracy and efficiency as well as communication patterns is described.

Computer Systems