Radiologists' productivity in the interpretation of CT scans: a comparison of PACS with conventional film.

OBJECTIVE: We compared radiologists' times in the interpretation of CT using hardcopy films with the interpretation using a soft-copy picture archiving and communication system (PACS) computer workstation. MATERIALS AND METHODS: One hundred CT examinations were selected at random and reviewed by four board-certified radiologists experienced in soft-copy interpretation. We performed time-motion analysis to determine the total time required to display, interpret, and dictate the individual findings of CT using conventional hard-copy interpretation on a viewbox and soft-copy interpretation, using a four-monitor high-resolution (2048 x 1536 pixel) workstation. RESULTS: Time-motion analysis showed a reduction of 16.2% in the overall time required for soft-copy interpretation of CT compared with that of film. Time savings with soft-copy interpretation were observed for all four participating radiologists. The benefit of soft-copy interpretation was increased for examinations in which there were comparison studies. CONCLUSION: We found that soft-copy interpretation of CT using a PACS workstation requires less time than interpretation using conventional film hung on a viewbox. The transition to filmless imaging has the potential to improve radiologists' productivity and report-turnaround time.

Challenges associated with interfacing computed tomography to a picture archiving and communication system at the Baltimore Veterans Affairs Medical Center--a historical perspective.

The interfacing of digital image acquisition modalities to the picture archiving and communication system (PACS) plays a major part in the conversion from a traditional film-based radiology practice to one that relies almost entirely on soft-copy reading. The Baltimore Veterans Affairs Medical Center (VAMC) is one of the first filmless hospitals in the world. Since 1993, it has used computed tomography (CT) scanners connected to a commercial PACS to provide digitized patient images for filmless reading. Over the years, the evolution of Digital Imaging and Communications in Medicine (DICOM) standards, advances in networking technologies, and enhancements in PACS and hospital information system (HIS) software have greatly improved this system's robustness and patient/study identification accuracy. The result has been a major increase in productivity.

Effect of filmless imaging on the utilization of radiologic services.

PURPOSE: To determine the effect of a large-scale picture archiving and communication system (PACS) on in- and outpatient utilization of radiologic services. MATERIALS AND METHODS: Data were collected at the Baltimore Veterans Affairs (VA) Medical Center (BVAMC) before and after implementation of an enterprise-wide PACS; the numbers and types of imaging examinations performed for fiscal years 1993 and 1996 were evaluated. These data were compared with those from a similar academic medical center, the Philadelphia VA Medical Center (PVAMC), and with aggregate data obtained nationally for all VA hospitals over comparable periods. RESULTS: Inpatient utilization, defined as the number of examinations per inpatient day, increased by 82% (from 0.265 to 0.483 examinations per patient day) after a transition to filmless operation at BVAMC. This is substantially greater than the increases of 38% (from 0.263 to 0.362 examinations per patient day) and 11% (from 0.190 to 0.211 examinations per patient day) at the film-based PVAMC and nationally, respectively. Outpatient utilization, defined as the number of examinations per visit, increased by 21% (from 0.108 to 0.131 examinations per visit) at BVAMC, compared with a 1% increase (from 0.087 to 0.088 examinations per visit) at PVAMC and a net decrease of 19% (from 0. 148 to 0.120 examinations per visit) nationally. CONCLUSION: The transition to filmless operation was associated with increases in inpatient and outpatient utilization of radiologic services, which substantially exceeded changes at PVAMC and nationally over the same interval.

Frequency and impact of high-resolution monitor failure in a filmless imaging department.

The purpose of this study was to assess the image quality and the rate of failure of the high-resolution (2,048 x 1536 pixel) monitors used for primary diagnosis in a filmless radiology department and to analyze the type of problems encountered as well as the action taken to repair the monitors. Data were collected from Picture Archival and Communication System (PACS) service logs to determine rates of monitor adjustment and replacement, the symptoms reported, and the action taken. Additionally, random surveys of the high-resolution monitors were performed using a standard test pattern to assess spatial and contrast resolution in the center and outer corners of the monitors. Analysis of monitor service records showed a high rate of monitor replacement (41% per year) resulting in a relatively short "life expectancy" (defined as average time required before replacement) of 2.4 years. Random surveys of monitor quality using a standard test pattern showed suboptimal image quality in approximately 54% of the monitors with moderate image quality degradation present in at least one region of 27% of the high-resolution monitors, despite our vendor's quality control program. The results of this study support our subjective impression and those of other colleagues in the PACS community of an unacceptably high monitor failure rate and persistent image quality problems with 2,000 pixel monitors used for primary diagnosis. The relatively high incidence of suboptimal quality monitors suggests that more frequent quality control should be performed using a test pattern particularly given the fact that radiologists often are unable to discern degradation of monitor performance using clinical images. The high incidence of problems with image quality on high-resolution monitors indicates that vendors need to develop better quality control in monitor design and testing. Radiologists should review briefly a test pattern on each monitor at the beginning of each day. A computer program should be incorporated into the PACS, which asks radiologists to evaluate a test pattern and records the results in a central database, which is communicated to the service engineers. Further studies should be evaluated to determine the clinical impact of monitor image degradation, which is relatively easily seen using a test pattern but may be difficult to discern on clinical images. Requests for proposals (RFPs) for PACS and service contracts must specify carefully requirements for monitor image quality and conditions under which the vendor is required to replace these monitors.

Challenges associated with the incorporation of digital radiography into a picture archival and communication system.

Digital radiography (DR) has recently emerged as an attractive alternative to computed radiography (CR) for the acquisition of general radiographic studies in a digital environment. It offers the possibility of improved spatial and contrast resolution, decreased radiation dose due to improved efficiency of detection of x-ray photons, and perhaps most importantly, holds out the promise of increased technologist productivity. To achieve maximum efficiency, DR must be completely integrated into existing information systems, including the hospital and radiology information systems (HIS/RIS) and, when present, the picture archival and communication system (PACS). The early experience with the integration of DR at the Baltimore Veterans Affairs Medical Center (VAMC) has identified several challenges that exist to the successful integration of DR. DR has only recently been defined as a separate Digital Imaging and Communications in Medicine (DICOM) modality and images obtained will, at first, be listed under the category of CR. Matrix sizes with some DR products on the market exceed the current size limitations of some PACS. The patient throughput may be substantially greater with DR than with CR, and this in combination with the larger size of image files may result in greater demands for network and computer performance in the process of communication with the HIS/RIS and PACS. Additionally, in a hybrid department using both CR and DR, new rules must be defined for prefetching and display of general radiographic studies to permit these examinations to be retrieved and compared together. Advanced features that are planned for DR systems, such as dual-energy subtraction, tomosynthesis, and temporal subtraction, will likely require additional workstation tools beyond those currently available for CR.

Impact of filmless imaging on the frequency of clinician review of radiology images.

The purpose of this study was to determine the impact of filmless imaging on the frequency with which physicians access radiology images and to assess clinician perception of image accessibility using a hospital-wide Picture Archival and Communication System (PACS). Quantitative data were collected at the Baltimore VA Medical Center (BVAMC), prior to and after conversion to filmless imaging, to determine the frequency with which clinicians access radiology images. Survey data were also collected to assess physician preferences of image accessibility, time management, and overall patient care when comparing filmless and film-based modes of operation. In general, there was a significant increase in the average number of radiology images reviewed by clinicians throughout the hospital. However, the one are in the hospital where this trend was not observed was in the intensive care unit (ICU), where the frequency of image assess was similar between film and filmless operations. Ninety-eight percent of clinicians surveyed reported improved accessibility of images in a filmless environment resulting in improved time management. The mean clinician estimate of time saved due to the use of PACS was 44 minutes. The study documented a combination of clinician perception of improved accessibility and substantial time savings with the use of a hospital-wide PACS, which was supported by objective measurements. The increased frequency of image review by clinicians and rapid image access should provide a further impetus to radiologists to decrease report turnaround time to provided "added value" for patient care.

Recommendations for image prefetch or film digitization strategy based on an analysis of an historic radiology image database.

Picture archiving and communications systems (PACS) utilize short- and long-term storage to provide both rapid retrieval and large storage capacity. Owing to the practical limitations imposed on the size of the much faster short-term storage, it is important to use an effective algorithm in the retrieval of comparison images from long to short-term storage. A strategy must be used to maximize the likelihood that the relevant historic images have been previously retrieved into short-term memory. Data were collected with a database consisting of 754 consecutive examinations and 7,723 associated historic studies. The most frequent number of previous examinations was zero (11% of patients). In 45% of cases, no previous matching examinations had been performed. Two basic strategies of image retrieval were evaluated. The first algorithm retrieved the last n studies in chronological order. The second strategy tested was retrieval based on a defined interval of time. This strategy was found to be less efficient. By using the former strategy, a 91% success rate (defined as successful retrieval of the previous matching exam) was achieved with retrieval of only 30% of the prior exams. The second approach required retrieval of 70% of the prior exams to achieve a 90% success rate for the previous matching exam. However, the data from this latter strategy suggest that examinations are often ordered in clusters. Thus, there was found to be a 72% likelihood that a previous matching exam, if present, would available on a PACS after only 1 week of operation, and an 80% chance after only 1 month of operation. The data therefore suggest that digitization of film in a new PACS environment might not be necessary owing to the relatively short period of time required to populate the database with historical studies.

Effect of film-based versus filmless operation on the productivity of CT technologists.

PURPOSE: To determine the relative time required for a technologist to perform a computed tomographic (CT) examination in a "filmless" versus a film-based environment. MATERIALS AND METHODS: Time-motion studies were performed in 204 consecutive CT examinations. Images from 96 examinations were electronically transferred to a picture archiving and communication system (PACS) without being printed to film, and 108 were printed to film. The time required to obtain and electronically transfer the images or print the images to film and make the current and previous studies available to the radiologists for interpretation was recorded. RESULTS: The time required for a technologist to complete a CT examination was reduced by 45% with direct image transfer to the PACS compared with the time required in the film-based mode. This reduction was due to the elimination of a number of steps in the filming process, such as the printing at multiple window or level settings. CONCLUSION: The use of a PACS can result in the elimination of multiple time-intensive tasks for the CT technologist, resulting in a marked reduction in examination time. This reduction can result in increased productivity, and, hence greater cost-effectiveness with filmless operation.

Use of computed radiography in the study of an historic painting.

The authors demonstrate the use of radiography in the investigation of an historic painting and describe the potential benefits of computed radiography compared with conventional screen-film radiography. The subject for the comparison was a 16 x 19-foot oil-on-canvas painting, Scipio Africanus Freeing Massiva, by Giovanni Battista Tiepolo. Radiographs of the painting were obtained by using a portable, industrial radiographic unit and both conventional screen-film and photostimulable phosphor plate cassettes. For this investigation, computed radiography had a number of advantages over screen-film radiography, largely due to its wider dynamic range and its capabilities for enhancing the digital images with image processing tools such as magnification, edge enhancement, colorization, and airbrushing. The ability to electronically combine images from the large painting into a single composite image file was extremely valuable, as this technique was much less cumbersome and resulted in much higher quality composite images than could be achieved with conventional radiography. An additional advantage of computed radiography includes the capability to easily archive and transmit these images in a digital format for subsequent review.

Picture archiving and communication systems and vascular surgery: clinical impressions and suggestions for improvement.

The purpose of this study was to determine the acceptance and clinical utility of a large scale picture archiving and communication system (PACS) for vascular surgery. Questionnaires and one-on-one interviews were conducted with physicians and nurses in the department of vascular surgery at the Baltimore VA Medical Center where PACS has been in routine, hospital-wide use for more than 2 1/2 years. The perceptions of the clinical staff were assessed to determine the efficacy of PACS in comparison to the conventional film based alternative for the practice of vascular surgery and suggestions for improvements were solicited. There was consensus among the vascular surgery staff members that the use of PACS enhanced their clinical practices, both in and out of the operating room (OR). Vascular surgeons heavily rely on image display in the OR as a "road map" to help determine their operative approach and to guide their surgery. PACS offers unique intraoperative imaging capabilities including rapid image retrieval and improved archival, cine review, the ability to modify image contrast, and the ability to obtain direct quantitative measurements of the degree of vascular stenosis. The increased accessibility and availability of images throughout the hospital enables improvement in time management and in patient care.

Experience and design recommendations for picture archiving and communication systems in the surgical setting.

An analysis of the efficacy of a picture archiving and communication system (PACS) in the surgical domain was undertaken at the Baltimore Veterans Affairs Medical Center. Interviews with surgeons and staff were conducted and supplemented by direct radiologist observation in the operating room (OR) and surgical outpatient clinic to determine patterns of routine clinical PACS use, levels of satisfaction both within and outside of the OR, and perceptions of the relative efficacy of the system in comparison to film. These data as well as suggestions from the surgical staff members were used to make recommendations for specific modifications in PACS design and operation to improve the current system and to help prescribe design improvements for future PAC systems. A high level of satisfaction with the system was found and the use of PACS was favored over film by a majority of surgeons and their staff. Findings of this study suggest that the design of a hospital-wide PAC system must have the flexibility to accommodate the specific requirements of a wide variety of end-users in their unique hospital environments.

Picture archiving and communication system training for physicians: lessons learned at the Baltimore VA Medical Center.

Physicians practicing at the "filmless" Baltimore VA Medical Center need to be proficient in the use of the picture archiving and communication system (PACS) to be able to view radiologic images and accompanying reports. PACS training is necessary to assure optimal patient care and to satisfy potential medicolegal requirements. Providing such training is the responsibility of both the Imaging Department and the hospital. Training in the use of the PACS at the Baltimore VA is conducted by an on-site application specialist. Data were collected from interviews with the trainer, training log sheets, and physician surveys. Although 100% of radiologists received formal training, only 22% of nonradiologists were formally trained; 32% of these physicians identified themsleves as having been trained by their peers and 41% stated they were self-trained. We identified two goals of a PACS training program. The first is to teach physicians how to retrieve images and reports from current as well as prior studies and display them on a computer workstation. Secondly, the training should include instruction on the use of the various workstation tools to enhance image interpretation. Imaging requirements and usage by different physician groups vary, and PACS training should be tailored accordingly. Difficulties in the scheduling of training sessions during working hours and the widespread use of a "generic" log-on identification have contributed to the low (22%) compliance of nonradiologists with the formal training program. Although we believe that one-on-one training is most effective and can be best tailored to the needs and computer expertise of an individual particular physician, computer based training (both on and off-line) may provide an acceptable, and in some cases, a preferred alternative.

Double injuries of the forearm: a common occurrence.

To evaluate the frequency of different types of forearm fractures and, in particular, determine the frequency of double injury to the forearm, the authors prospectively examined 119 consecutive forearm fractures and found double injuries to the forearm in all but five cases. In 79 of the 119 patients (66%), ligamentous injury was seen in addition to the obvious fracture. Nine patients with apparent isolated fractures on initial radiographs underwent examination by means of radionuclide bone scanning, which revealed a second injury in eight of them. Four patients with apparent single fractures did not undergo bone scanning because of their critical conditions. In four patients, a single fracture was initially diagnosed, but after reduction and casting, dislocation of the radioulnar joint was seen. These findings indicate that injury to the forearm almost invariably occurs at two or more sites and involves either both bones or bone and ligament. Because the distal radioulnar joint was affected in 71 patients (60%), scrutiny of the wrist is imperative whenever injuries to the bones of the forearm are discovered.

Osseous drill holes to promote granulation tissue: radiologic appearance.

Skin grafting following extensive soft-tissue loss is often delayed until adequate granulation tissue can be generated. Surgical drill holes into the marrow cavity promote development of granulation tissue. This article illustrates the radiology appearance of these drill holes in four patients.

Right-to-left shunting via persistent left superior vena cava identified by perfusion lung scintigraphy.

A right-to-left shunt was demonstrated following a left antecubital injection of [99mTc]MAA but was not seen after a right antecubital injection. This was because of the presence of a persistent left superior vena cava draining into the left atrium. Recognition of the presence of this anatomic variant is of importance in perfusion imaging, in patients with otherwise unexplained systemic embolization.

Protocol-driven radiologic evaluation of suspected cervical spine injury: efficacy study.

The American College of Surgery currently recommends routine performance of lateral cervical radiography of C-1 to C-7 for all patients admitted with a history of major blunt trauma. A survey of 125 North American hospitals with experience in acute trauma care revealed that 96% obtain cervical radiographs as a routine or protocol study on all patients who have suffered major blunt trauma. To ascertain the cost-benefit effect of this practice, a prospective study was conducted during a 19-month period to compare the results of admission bedside clinical assessment of the cervical spine and the outcome of cervical radiography and computed tomography (CT) performed on 408 patients admitted with a history of major blunt trauma. Among these patients, there were 138 (34%) who were judged to be mentally alert and without symptoms referable to cervical spine injury. CT was performed after cervical radiography to adequately visualize the lower cervical spine (132 patients) or to clarify uncertain radiographic findings (six patients). One nondisplaced transverse process fracture of C-7 was detected (a prevalence of less than 1% of asymptomatic patients). The combined cost of cervical radiography and CT for the 138 asymptomatic patients was $59,202. These results call into question both the cost and clinical efficacy of routine or protocol-driven cervical spine imaging for all patients who have sustained major blunt trauma and support the value of careful bedside clinical assessment of the cervical spine in mentally alert blunt-trauma victims.