Eric R. Feingold

Radiology workflow and patient volume: Effect of picture archiving and communication systems on technologists and radiologists

This study was performed to evaluate the changes in workflow and efficiency in various clinical settings in the radiology department after the introduction of a picture archiving and communication system (PACS). Time and motion data were collected when conventional image management was used, and again after the introduction of a PACS. Changes in the elapsed time from examination request until the image dispatch to the radiologist, and from dispatch until report dictation, were evaluated. The relationship between patient volume and throughput was evaluated. The time from examination request until dispatch was significantly longer after the introduction of PACS for examinations taken on patients from the emergency department (ED) (pre-PACS, 20 minutes; post-PACS, 25 minutes;P<.0001), and for examinations taken on patients in the medical intensive care unit (MICU) (pre-PACS, 34 minutes; post-PACS, 42 minutes;P<.0001). The interval from image dispatch until report dictation shortened significantly after the introduction of PACS in the ED (pre-PACS, 38 minutes; post-PACS, 23 minutes;P<.0001) and in the outpatient department (OPD) (pre-PACS, 38 minutes; post-PACS, 20 minutes;P<.0001). Simple least squares regression showed a significant relationship between daily patient volume and the daily median time until report dictation (F=43.42,P<.001). PACS slowed technologists by prolonging the quality-control procedure. Radiologist workflow was shortened or not affected. Efficiency is dependent on patient volume, and workflow improvements are due to a shift from batch to on-line reading that is enabled by the ability of PACS to route enough examinations to keep radiologists fully occupied.

Folder management on a multimodality PACS display station

The Radiology Department at the University of Pennsylvania is installing a clinical picture archiving and communication system (PACS). The first phase of the PACS will support two MRI scanners, one film digitizer, and will provide display stations for four intensive care units and the MRI section. The software design for the image display stations has taken the form of two software modules: a display process (DP) and a worstation folder manager (WFM). This layered approach will ease the addition of new display stations into the PACS. The two processes communicate directly and through a folder database (FDB) that resides on the display node. The DP will allow the user to view and perform spatial and grayscale manipulation on multimodality images displayed on two high-resolution (2560 H X 2048 V) grayscale monitors. The WFM is responsible for processing folder requests from the DP, receiving folders from the main archive folder manager (MAIN_FM), fetching images from the image archive and retrieval system (IARS), and maintaining the FDB. All communication between the WFM and both the MAIN_FM and IARS is performed using ACR-NEMA style messages. The WFM has the ability to receive unsolicited folders in addition to folders on request. The WFM can also generate return folders for the MAIN_FM that contain physician reports of viewed images.

An Automated Results Notification System for PACS

The purpose of this study was to determine if the interval between an examination being ordered by an Emergency Department physician and his or her review of the report and images could be shortened by notifying the physician that the results were available. This hypothesis was based on work done previously in the Medical Intensive Care Unit that showed that physicians would wait to review results for a time considerably longer than the time required for the radiologist to review the images and provide a preliminary report. The software developments operate properly and show that even simple integration of multiple information systems (PACS, RIS, speech recognition) can provide useful features. Early results indicate that the Emergency Department (ED) physicians prefer the notification system over the previous (travel to check on images and reports) methods. The hypothesized time reductions did occur, although it is not clear that the notification system accounted for all of them. A system for automated notification of radiology results availability has been shown to be possible and practical. To do this automated interaction of 3 systems with a low-level or no electronic integration was required. Although not fully successful for this study, early physician response has been positive, and requests to expand this service hospitalwide now are common.

WWW to DICOM interface

In this paper we discuss the implementation and use of a WWW interface to a DICOM PACS that allows users to select, move, and display images that are currently available in the PACS and to view their corresponding radiology reports. This system allows our users to query the archive from any workstation (such as Unix, DOS, and Mac) that supports a WWW browser. To use this system, the user first runs a WWW browser such as Mosaic, Netscape, or Lynx and specifies a URL on one of our Unix workstations. This URL refers to an HTML file that contains a query form. This query form contains a number of fields such as patient name and medical record number. The user may specify any or all fields as well as wildcards in fields such as the name field. Once the form is completed, the user presses a button to submit the request. The HTML form submits the query to a C program that executes on the Unix server. This program accepts as input the form field values that the user specified. This program then communicates with the archive via DICOM requests to determine those patients that match the search criteria. The user may then choose a patient which in turn causes the studies for this patient to be displayed. Finally, the user may select a study which causes those images to be retrieved from the archive and displayed via the Web browser. The result of this system is an easy to use interface to a DICOM PACS with the option to query and move images from the PACS. In summary, a system that integrates the ease of use of WWW browsers with a DICOM PACS is discussed. We are currently incorporating information from our RIS as well. This allows us to obtain extensive patient demographics, exam information, and textual radiological reports and associate this information with information from the PACS.

Assessing the impact of PACS on patient care in a medical intensive care unit

In this paper we have present data from pilot studies to estimate the impact on patient care of an intensive care unit display station. The data were collected during two separate one-month periods in 1992. We compared these two different periods in terms of the relative speeds with which images were first viewed by MICU physicians. First, we found that images for routine chest radiographs (CXRs) are viewed by a greater number of physicians and slightly sooner with the PACS display station operating in the MICU than when it is not. Thus, for routine exams, PACS provide the potential for shortening of time intervals between exam completions and image-based clinical actions. A second finding is that the use of the display station for viewing non-routine CXRs is strongly influenced by the speed with which films are digitized. Hence, if film digitization is not rapid, the presence of a MICU display station is unlikely to contribute to a shortening of time intervals between exam completions and image-based clinical actions. This finding supports the use of computed radiography for CXRs in an intensive care unit.

Experience with radiology workflow and PACS: effects on technologist and radiologist task times

To evaluate the changes in workflow, in the radiology department, after switching from a film-based image management system to a picture archival and communication system.

Web based Radiology applications for clinicians and radiologists

The University of Pennsylvania Radiology Department has developed a suite of Web based applications for clinicians and radiologists to provide wide spread, cost-effective and easy access to radiological information. The Image Viewer application provides clinicians and radiologists access to all diagnostic reports and digital images performed in the last week for all Emergency Dept., Intensive Care Unit and Neuro/CT studies. Image control options including zoom/pan, rotate, flip, and window/level are all available. The image mover/viewer application gives radiologists and technologists the ability to both move studies between any DICOM Storage Class Provider (SCP) and DICOM storage class user (SCU) and to view studies from any DICOM displayed. Web server support requires integration using Perl based CGI scripts with our DICOM/PACS and the MIR/CTN for images and our IDXrad/RIS for reports. Targeted images and reports are automatically routed from the PACS and RIS for storage on the web server. All images sent to the web server are modality specific per-processed to reduce size and improve contrast. After processing, all images are stored in DICOM and GIF formats. Client support requires web browsers with JavaScript and frame support.

What do we need to advance PACS workstations: a critical review with suggestions

The technology for building workstations suitable for the display of most medical images has existed for almost a decade. Yet the diagnostic interpretation process has not shifted form film to such workstations in early as large numbers as had been predicted. While, in a large part, this is due to the high costs for acquisition of picture archiving and communications system equipment, there is also the aspect of physician acceptance. Since the workstation serves as the primary system-to-person interface, an examination of the way in which workstations are designed and the way in which radiologists actually work yields some insight into the relative lack of penetration of workstations into the diagnostic image interpretation task.

On-demand retrieval paradigm

The University of Pennsylvania Medical Center has been operating a prototype clinical PACS for a number of years. The details of this implementation have been described elsewhere. Early on in the design phase we realized the need to pre-fetch images on a PACS network and incorporated rule-based pre-fetch mechanisms into our Folder Manager software suite. As our PACS expanded and as the pool of users increased to include MR technologies and researchers in addition to radiologists, the case for an on-demand retrieval mechanism became compelling. The design of such a paradigm posed special problems in that the system had to be robust and user-friendly. This paper discusses the design and implementation of such a system. Usage statistics collected over a one-year period are also presented. The retrieval profile shows certain patterns that can be exploited to improve the design of the PACS.

Prototype controls for a plain radiography workstation

The purpose of this work was to develop a set of controls for image navigation and manipulation for use at a workstation. The intended focus was to provide a set of controls that would be most useful for the task of reading plain radiographs, such as those from chest, abdominal, and musculoskeletal imaging. We thought that most workstation controls were better suited to the interpretation of cross sectional imaging rather than plain radiography, and from current reports on user ergonomics and our own experience, developed a prototype control set. A goal of this design was to create controls that could be operated without the need to display menus on the workstation or select items from them. The control set was also designed to be operable without having to do visual searches for the controls or observe the controls while they were being used.