Applied Radiology

Reprinted from: Honeyman-Buck JC. Productivity and workflow in a PACS environment. Appl Imaging: Curr Trends PACS . 2002;1(1):1-3. © Anderson Publishing, Inc.

Among the potential benefits of installing Picture Archiving and Communication Systems (PACS) and the Electronic Radiology Practice (ERP) were the possibilities of improving productivity and workflow by eliminating film and paper handling, thus allowing technologists, clerks, and radiologists to do a more efficient job. In theory, the improved accessibility to reports and images would also improve the efficiency of the treating physician and would improve patient care with more timely treatment. Although improvements in productivity and throughput have been reported, PACS is not the panacea for all radiology productivity problems. With careful planning and increasing communication among information systems, however, there is hope that automation will improve workflow and result in efficiencies in all phases of the radiologic examination.

In order to make sense of the reports generated by various authors, it is necessary to define the components of a total ERP and how they fit together to make an automated system. For the purposes of this paper, PACS will be the center of the ERP, providing the capability of acquiring, transmitting, storing, and displaying images generated by radiology modalities. The Hospital Information System and/or Radiology Information System (HIS/RIS) provide accurate information about the patient, his or her location in the hospital or clinic, orders for that patient, medical information on the patient, and the completed radiology reports. Radiology orders are typically placed using the HIS/RIS. The Voice Recognition System (VRS) automatically transcribes the report using voice recognition as the radiologist interprets the study. In practices where VRS is not used, some type of dictation-transcription system is used, generally with the radiologist identifying the patient and study, then dictating the results for a transcriptionist to enter into the reporting system or HIS/RIS. Figure 1 illustrates a simplified workflow in an ERP environment.

The technologist's perspective

Before digital radiography and PACS, the general radiological technologist exposed a film-screen cassette that had to be identified as belonging to a specific patient, then processed either in a darkroom or a daylight processor. Computed radiography (CR) equipment replaces the film with a phosphor plate that can be read, erased, and reused, but still needs to be identified and processed. Other than reducing retake rates because of the wider gray-scale latitude, productivity may not improve using just this technology. However, in a study comparing three departments, two with conventional film-screen and one with CR, the mean examination times for the department using CR was significantly lower than the ones using film-screen. ¹ The study reports the average examination time for a two-view chest study as 12.5 minutes with film-screen and 7.4 minutes with CR, while the average time for a three- to five-view spine study as 19.1 minutes with film-screen and 8.8 minutes with CR. When digital radiography (DR) is used, there is greater potential for improving productivity since the technologist is not required to handle cassettes and can concentrate on positioning and exposure. In one study reported earlier this year, film-screen was compared with both CR and DR. ² The authors reported an improvement in throughput for the digital modalities, with DR being the most efficient. Measured in patient throughput per hour for chest examinations, the film-screen room handled 8.2 examinations, the CR room handled 9.2 and the DR room handled 10.7. The more striking statistic in this work is the time measured until images were available for interpretation. With the conventional film-screen system where films were hand delivered to the reading room, the average time from the start of the examination to the time when films were available for interpretation was 29.2 minutes, for CR the average time was 6.7 minutes, and for DR the average time was 5.7 minutes.

Technologists still have the responsibility of assuring the correct patient information is attached to a study. In a digital system without a connection to the HIS/RIS, this information must be entered by hand in what is frequently a time-consuming process. When there is a connection to the HIS/RIS, usually called a DICOM Modality Worklist, the technologist can swipe a bar-code or select a patient from a list and complete and correct patient information will be associated automatically with the images in the PACS. This saves time and vastly improves the accuracy and, ultimately, the usability of the PACS. Two studies comparing throughput for film-screen with DR with no Modality Worklist and DR with Modality Worklist produced strikingly similar results. ^3,4 In each case, chest examination times were measured and the total time in the department was reported. In the first study, the average time in the department was 307 seconds for film-screen, 142 seconds for DR with no HIS/RIS, and 98 seconds for DR with the HIS/RIS interface. ³ In the second study, the average time in the department for film-screen was 338.9 seconds, for DR with no RIS/HIS was 138.8 seconds and for DR with the RIS/HIS interface was 94.9 seconds. ⁴

A similar study was performed comparing the length of time required to complete a CT study in a "filmless" PACS department with the time in a film-based environment. When technologists no longer printed images at multiple window and level settings, the time required to complete a CT examination was reduced by 45%. ⁵

The radiologist's perspective

Although cost justification for PACS has a productivity component, radiologists' time is usually not considered because they are usually not considered a cost center by the hospital. However, several authors have investigated the effect of the ERP, particularly PACS and voice recognition, on radiologists' productivity. One study compared the time required to read CTs from printed films with the time required to read from four-monitor PACS workstations. ⁶ Films were printed using a 12-on-1 format and comparison studies were printed and placed in the film jacket for use. Radiologists were allowed to choose their formats on the PACS workstations and window and level presets were used during the interpretation. A selection of chest, abdomen, and brain studies were chosen for the study. There was an overall reduction of 16.2% in the total time required for CT interpretation with soft-copy compared with conventional film. When comparison studies were used, a significantly greater productivity gain was realized. The greatest time savings observed was with chest interpretations, for which the time savings with PACS and no comparison study was 1.79 minutes and PACS with a comparison study was 4.44 minutes.

Hayt and Alexander ⁷ evaluated the effects of PACS and voice recognition on radiologist's productivity. They found that the combined systems resulted in a decrease in radiologists' productivity. The radiologists were asked to describe how the system effected their reading times, and were given the options of less time, the same amount of time, or more time spent in increments of 25%, 50%, 100%, and 200%. Ten radiologists responded, 2 reported an increase of 25% and 8 reported a >100% increase in their time. However, there were a number of striking positive benefits of the system. The percentage of unreported cases at the end of each month dropped from approximately 25% to 0.3% with the ERP. Clinicians who responded to a survey reported that PACS had saved them approximately 30 minutes per day. With the installation of the voice recognition system, the percentage of reports present in the HIS within 12 hours after dictation increased from 3% to 42%. After PACS was installed, 50% of all examinations had reports available within the HIS within 60 minutes, 86% available in 12 hours, and 96% available in 24 hours. One of the weaknesses in the system studied was the lack of integration between the PACS and voice recognition. Radiologists bar-coded an accession number to bring up the voice recognition software, and then chose a study from the PACS on a separate workstation. A close integration of the two systems would improve productivity by eliminating the extra steps.

The bottom line

An ERP can improve productivity in the right environment for technologists and for medical personnel who need to access images and reports. As reported by Hayt and Alexander, ⁷ a marked improvement in the availability of reports was seen, primarily at the expense of the radiologist. Another benefit of PACS was described by Becker and Arenson, ⁸ who studied the correlation of the availability of images and the mean time to drug therapy. When clinicians had access to digital images, the mean time to drug therapy was 3.3 hours, with film the mean time was 4.7 hours.

Several authors have commented that ineffiencies arose when the PACS, HIS/RIS, and voice recognition systems were not integrated closely. When patient and study information is not available on the modality through DICOM modality worklist, technologists must enter the data manually, which is time consuming and introduces errors. When radiologists must access two separate computers for voice recognition and PACS, they double their searching time and can introduce reading errors by selecting inconsistent image and report data. Paper requisitions and reports are still the norm in many radiology departments, which leads to more inefficiency. When PACS is implemented, many of the routing and prefetching operations must be automated to achieve a high degree of productivity. With full automation, Siegel and Reiner ⁹ reported increased efficiencies for technologists of 20% to 60%, clerical staff of >50%, and radiologists of >40%.

A tight integration of all components of the ERP is necessary to achieve overall improvements in productivity. The Radiological Society of North America (RSNA) and the Healthcare Information management Systems Society (HIMSS) have collaborated to sponsor a "phased series of public demonstrations of increasing connectivity and systems integration," called Integrating the Healthcare Environment (IHE). ^10,11 The IHE demonstrations have encouraged HIS/RIS and PACS manufacturers to agree on ways to use the existing standards to facilitate interaction. Only when we have an integrated ERP with all components communicating and a workflow management layer on top will we truly realize the productivity improvement potential of these new systems.