- Email: [email protected]
A prospecive evaluation of the impact of filmless operation on the Baltimore VA Medical Center
A prospective evaluation of the impact of filmless operation on the Baltimore VA Medical Center EL Siegel, Z Protopapas, B Reiner, S Pomerantz, EW Cameron, E Pickar
he Baltimore Veterans Affairs Medical Center (BVAMC) is a 300 bed tertiary referral center for veteran patients located adjacent to the University of Maryland Hospital in downtown Baltimore, Maryland. The imaging department (radiology and nuclear medicine) performs approximately 60,000 examinations per year. Both the medical center and the imaging department, which have been in operation for almost 4 years, were designed to facilitate filmless operation. This design included fiberoptic cable throughout the medical center, a computer room in the imaging department, a 16 inch image intensifier for our angiograms and ‘special procedures’ and digital interfaces purchased with the various modalities 11-31 (table I).
Materials and methods All conventional radiographs are obtained using computed radiography with the images transferred directly to the Picture Archival and Communication System (PACS). Images obtained from Computed Tomography, angiography and ‘special procedures’, ultrasound, fluoroscopy, nuclear medicine, the cardiac catheterization laboratory, and a portion of the magnetic resonance images (MRI) are also sent directly to the PACS without any film being printed 1101. The two exceptions to filmless operation are in mammo-
graphy which is currently performed and interpreted conventionally using film screen with the images subsequently digitized into the PACS and a subset of the MRI studies which are both sent to PACS and then printed to film. The mammography section is currently making the transition to a full breast digital mammography system which is expected to utilize a DICOM interface. A software update which will facilitate the interpretation of MRI is expected to permit the transition to 100 % soft-copy interpretation for MRI as well. The majority of the ten workstations in the radiology department utilize a Macintosh II (Apple Computer, Cupertino, CA) or Quadra 950 system with four monitors (2,048 x 1,536 pixels). The average brightness of the 2,048 x 1,536 pixel monitors is approximately 60 foot lamberts with a refresh rate of approximately 60 MHz. The 34 workstations located throughout the remainder of the medical center are, for the most part, in a two monitor (1152 x 1078 pixels) configuration and use a Quadra 950 computers. The monitors are arranged in a horizontal, ‘fouracross’, configuration. These workstations are located in the patient clinics, emergency room, intensive care units, operating rooms, physician ‘team’ offices, the auditorium, and in the medical media department 181. In addition to the commercial system described above (Loral Medical Imaging Systems), the
Baltimore VA Medical Center, ’ 0 North Greene Sreet, Bait more, Iclar$and 212’31 and University of Maryland Medical School, USA RBM
(1996)
l&3,149-152
0 Elsevier,
Paris
EL Siegel,
Z Protopapas,
B Reiner
et a/
Table I. Modalities and interfaces to the Picture Archival and Communicatiqn System (PACS). Modality Computed radiography Computed tomo&&hy Computed tomography Magnetic resonance Ultrasound Digital fluoroscopy Digital angiography Nuclear medicine Cardiac catheterization lab
,Mandactim Fuji GE Picker Picker ATL Siemens Siemens Picker Phillips
Table II. Image types available on the DHCP imaging system (hospital inforrnation svstem). -
I
Radiology images transferred frism the radiology/nuclear medicine PACS GI end© Bronchoscopy Dermatology Patient photographs Electrocardiograms Intra-operative photographs * Pathology Me&al documents (available using document scanner)
medical center utilizes a second PAC system developed by the Veterans Administration called the Decentralized Hospital Computer Program (DHCP) Imaging system. This image management system enables the Hospital Information System (HIS) to obtain, archive, and permit display of all images generated in the hospital including all of the examinations obtained on and transferred from the commercial radiology/nuclear medicine PAC system (table II). Of the 50 DHCP Imaging workstations which are located throughout the medical center, only three are in the imaging department. The current operating system for these workstations is Windows 95 or Windows NT and they utilize ‘off the shelf Pentium based ‘personal’ computers which are equipped with a 4 megabyte video display card. Unlike the commercial PACS, the DHCP Imaging system supports color images (24 bits). The workstation monitors typically display on a 17 inch diagonal monitor an image at a resolution of 1,280 by 1024 pixels although the workstations can support a variety of monitors up to a 2,000 by 2,500
Jntedce Proprietary (non-standard) int&ce DICOM DICOM DICOM DIISOM ACWNEMA MERGE (non-standard) intcjrface DlCOM Video Capture (8 bit)
pixel display. These workstations are currently utilized primarily for secondary diagnosis (not primary diagnosis by a radiologist), are relatively slower in performance, but are considerably less expensive than those provided by the commercial system (table 111). Both the commercial and the DHCP imaging PAC systems communicate bi-directionally with the Hospital Information System. The HIS is considered to be the ‘master’ database and all physician orders for imaging studies, imaging reports, and patient demographic and other data are entered into this system. The data is then transferred to the commercial PACS enabling ‘paperless’ operation by the radiologists who are able to retrieve old reports and ordering information in addition to prior images for comparison. In addition to providing images for the Baltimore VA Medical Center, the PAC systems serve as a central archive for images from three other hospitals in the state of Maryland. Images are sent to the PACS using ‘Tl’ phone lines, are archived and can be reviewed and/or interpreted using the commercial PACS or the DHCP Imaging system and can then made available for electronic review at those hospitals. The four hospitals currently share a single Hospital Information Sy,stem (HIS) and Radiology lnformatlon System (RIS). Thus, each facility has full access to all image and text information for the veterans who may visit individual hospitals for subspecialty care. The commercial PAC system was installed and became operational at the Baltimore VAMC during June 1993, approximately 5 months after the hospital opened for patients. Just prior to this, a three RRM
(ly96) IEio
18, i
phase prospective study was begun to determine the impact of filmless operation on the medical center [51. The first phase consisted of baseline data collection prior to the transition to filmless operation. Data were collected for a period of approximately 2 months. The second phase of data collection occurred during the approximately 6 month transition period from film based to filmless operation after the PACS was installed, during which images were available both on computer workstations and on film. The third phase of data collection occurred after the transition to filmless operation was complete. These data were subsequently compared and analyzed [6,91.
Results The amount of time required to display a portable chest radiograph and the previous three studies for comparison was measured by direct observation for three operational scenarios (table IV). As would be expected, image display was much faster when images were ‘pre-hung’ by the film library personnel on an alternator in comparison to the case in which the radiologist puts up and takes down the films for each study. Although the use of the computer software display tool (default display protocol) almost halved the display time, image arrangement using the computer workstation was still approximately 30 % slower than manual display of films using a conventional lightbox. The percentage difference between the total time required to both display rind interpret an imaging study using the alternator or conventional viewbox and that required for interpretation using the computer workstation was relatively small (table IV). However, interpretation using a film alternator or conventional lightbox was still slightly faster than diagnosis using a computer workstation. Despite the fact that ‘soft-copy’ interpretation using a computer workstation was found to be somewhat slower than with film, the radiologist productivity actually increased after the introduction of the PACS by more than 50 7%.
Prospective
evaluation
There was an increase in volume (probably unrelated to the introduction of PACS) by more than 50 % without a significant change in the number of radiologists, resulting in this increase in productivity. This seemed to occur without a change in the perceived number of hours worked or percentage of time spent in image interpretation by the radiologists themselves. Factors that could explain this increase in productivity after the introduction of filmless operation include fewer interruptions by clinicians (since they tend to visit the imaging department less often), the fact that old exams and reports are organized and available using the PACS, better ability to share workload among all radiologists, the availability of all images to all radiologists at all times, and the fact that the radiologists do not have to wait for images to be matched and brought for interpretation by the film library personnel 1121. In the computed tomography division, radiologist reading times were found to be approximately 15 % faster with the use of a four monitor computer workstation in comparison with the case in which radiologists hang their own films. This increase in speed seems to be largely accounted for by the ability to rapidly modify window and level settings (eg lung, mediastinal, bone, and liver window/level settings for a thoracic CT) without having to take down and bring up additional films as is the case in a conventional CT reading room [ 111. The almost immediate availability of images for interpretation by the radiologists without waiting for films to be returned by clinicians or sorted and matched by the film library personnel has resulted in
of the impact
of filmless
operation
on the Baltimore
substantial decreases in the time from when an image is obtained until it is interpreted. A study performed comparing image interpretation times at the Baltimore VA with the adjacent University of Maryland demonstrated significant improvement in the number of studies interpreted within a short time or the same day as the study was performed with PACS in comparison to film. This has resulted in the ability of radiologists to interpret studies in a much more timely fashion. A subtle fracture can be diagnosed while a patient is in the emergency room or a retained common bile duct stone can be found by the radiologist with the patient still on the operating room table. The radiologists are able to both draw on and annotate images with appropriate markings or comments to bring attention to a pathologic process. The combination of computed radiography and soft-copy interpretation using the computer workstation has resulted in a significant decrease in the image retake rate from 5 % when using film to RBM
(1996) t&2
18,5
VAMC
below 1 R. The most common reason for image retakes has also changed with the transition to filmless operation from ‘sub-optimal technique’ to improper patient positioning. The ‘lost’ film rate as defined as a study which is not interpreted within a 2 week period after it was obtained has dropped from approximately 8 % to below 1 % with the use of the PACS. Average radiation dosage utilized for portable chest radiographs has dropped by approximately 30 % without a perceived difference in image quality. Investigations with cadaver specimens suggest that similar reductions in radiation dosages may be clinically adequate for other types of examinations as well 1131. Although hospital-wide parameters such as average length of stay and utilization rates of radiology services are potentially of critical importance, it is very difficult to determine the degree to which the use of the PACS has modified these indices. The average length of stay has dropped by over 25 % since the introduction of the sys-
EL Siegel, Z Protopapas, B Reiner et al
tern; however this is probably more likely due to economic and other factors than to the PACS. The degree to which filmless operation has affected this reduction is very difficult to measure. Additionally, the utilization of imaging services per inpatient day and outpatient visit has increased significantly. Similarly it is difficult to demonstrate the degree to which PACS has impacted utilization in comparison with other factors such as a change in the average complexity or acuity of patient care. Preliminary economic analysis suggests that the savings of approximately $650,000 in radiology and nuclear medicine personnel costs, supplies, and other expenses are almost completely offset by the maintenance contract of the system and capital depreciation on the PACS. However, a conservative reduction in the amount of time physicians spend retrieving images of as little as 10 minutes per day would result in savings of $200,000 to $400,000 per year at the Baltimore VAMC. Since the other three affiliated hospitals in Maryland utilize the Baltimore PACS for image archival which saves both radiologist and clinician time, savings associated with the PACS may be considerably higher than these estimates. A more formal economic analysis is currently underway to more precisely determine the economic impact of filmless operation and to develop a model to predict savings at other facilities which could result from the transition to filmless operation. Clinicians who are shared between the film based University of Maryland Medical System and the filmless Baltimore VA Medical Center were surveyed to determine their relative preferences for a conventional film based system in comparison to the PACS. There was a strong preference for PACS (92 %) in comparison to film based operation (3 % with 5 % having no preference). The clinicians indicated that they were more ‘comfortable’ with PACS and that filmless operation required less ‘effort’. They indicated a preference for PACS during teaching rounds predominantly due to improved availability of current and prior imaging studies. The clinicians did not seem to believe that PACS would significantly decrease leng-
th of stay. Only approximately 20 % of clinicians indicated that they had attending the formal PACS training course [151. The majority of those that did not attend the formal training program indicated that they were ‘self-taught’ (53 %) with most of the remainder relating that they had been trained by a colleague (41 %). A study conducted at Baltimore indicated that residents that had been given formal training did significantly better on a formal test of ‘critical’ PACS skills after one week of experience with the system than did those that were self-trained or taught by a colleague. Although the differences between these groups were still significant after 4 weeks, these differences were much less than those found at 1 week. Both trained and untrained groups were able to pass the basic PACS skills test. However, there were persistent differences even at 4 weeks in the amount of time required to use the PACS workstation for image review workstation. These differences suggest that economic benefits are achieved with formal PACS training (at least after 4 weeks of experience) in addition to the clinical benefits. Preliminary results with computer based training have been encouraging although these have not yet been quantified.
Conclusion
REFERENCES 1 Siegel E, Glass H (1992) Purchasing PACS, II 2
3
4
5
6
7
8
9
10
11
Practical experience and in-depth studies of the special requirements for PACS by orthopedic surgeons, vascular surgeons, the operating room staff, and the emergency room staff suggest that a number of improvements to the system and training could result in substantial improvements in the clinical utility of the system [7]. Subspecialty groups have unique requirements for training and location and accessibility of the workstation, monitors, and input devices [14,161. In conclusion, the 3,5 year experience with PACS has been very encouraging with significant improvements in imaging departmental efficiencies, delivery of timely services, clinician and radiologist satisfaction, and operating expenses. 4 RBM
(1996)
18,5
12
13
14
15
16
practical tutorial. S/CAR (Society of Computer Applications to Assist Radiology), p 5 Siegel E (1994) PACS at the Baltimore VA Medical Center. Planning, implementation strategies, and preliminary experience. In: Proceedings of the Korean PACS Society Siegel E, Pickar E (1994) The transition to the jilmless imaging department: early experience at the Baltimore VA Hospital. S/CAR (Society of Computer Applications to Assist Radiology), P5 Siegel E (1994) Parameters required to evaluate a jifmfess imaging system. S/CAR (Society of Computer applications to Assist Radiology), p 508 Siegel E, Brown A (1994) Preliminq impacts of PACS technology on radiology department operations. In: Proceedings of the Annual Symposium on Computer Applications in Medical Cure, 917-921 Siegel ES (1995) Impact of filmless radiology on the Baltimore VA Medical Center. In: Proceedings 1995 Military Telemedicine Symposium. IEEE Computer Society Press Pomerantz S, Siegel ES, I’rotopapas Z, Reiner BI (1995) Experience with PACS in the operating room in a filmless hospital. In: Proceedings of the 1995 Image Management and Communications Conjerence. IEEE Computer Society Press Siegel ES, Denner J, Pomerantz SM, Reiner BI, Protopapas Z (1995) PACS and medical media in a filmless hospital. In: Proceedings of the 1995 Image Management and Communications Conference. IEEE Computer Society Press Siegel ES, Pomerantz SM, Reiner BI, Protopapas Z (1995) PACS in a digital hospital: experience with filmless operation at the Baltimore VA Medical Center. In: Proceedings of the 1995 Image Management and Communications Conjerence. IEEE Computer Society Press Siegel ES (1995) The technology of PACS, a critical assessment. In: Proceedings of the 1995 Image Management and Communications Conference. IEEE Computer Society Press Pomerantz SM, Krebs TL, White CS, Daly BD, Sukumar S, Siegel EL, Protopapas Z, Reiner B (1996) Eficacy of routine reuiezo of liver and bone window settings in thoracic and abdominal CT imaging in the PACS environment. ARRS Siegel ES, Diaconis JD, Pomerantz SM, Allman RA (1995) Making PACS Work. J Digital Imaging, November 1995. Reiner BI, Siegel ES, Pomerantz SM, Allman RA, Fritz S, Hooper F, Protopapas Z (1996) The detection of foreign bodies in soft tissues: a comparison of computed radiography, conventional film, and computed radiography soft-copy. Am J Rudiof (in press) Reiner 81, Siegel ES, Hooper F, Pomerantz S, Protopapas Z, Pickar E, Killewich L (1996) PACS and vascular surgery: clinical impressions and suggestions for improvement. r Digital Imaging (in press) Protopapas Z, Siegel E, Reiner B, Pomerantz S, Pickar E, Wilson M, Hooper F (1996) PACS training for physicians: lessons learned at the Baltimore VA Medical Center. ] Digital Imaging (in press) Pomerantz S, Siegel E, Protopapas Z, Reiner B, Pickar E (1996) Experience and design recommendations for Picture Archiving and Communication Systems (PACS) in the surgical setting. J Digital Imaging (in press)
he Baltimore Veterans Affairs Medical Center (BVAMC) is a 300 bed tertiary referral center for veteran patients located adjacent to the University of Maryland Hospital in downtown Baltimore, Maryland. The imaging department (radiology and nuclear medicine) performs approximately 60,000 examinations per year. Both the medical center and the imaging department, which have been in operation for almost 4 years, were designed to facilitate filmless operation. This design included fiberoptic cable throughout the medical center, a computer room in the imaging department, a 16 inch image intensifier for our angiograms and ‘special procedures’ and digital interfaces purchased with the various modalities 11-31 (table I).
Materials and methods All conventional radiographs are obtained using computed radiography with the images transferred directly to the Picture Archival and Communication System (PACS). Images obtained from Computed Tomography, angiography and ‘special procedures’, ultrasound, fluoroscopy, nuclear medicine, the cardiac catheterization laboratory, and a portion of the magnetic resonance images (MRI) are also sent directly to the PACS without any film being printed 1101. The two exceptions to filmless operation are in mammo-
graphy which is currently performed and interpreted conventionally using film screen with the images subsequently digitized into the PACS and a subset of the MRI studies which are both sent to PACS and then printed to film. The mammography section is currently making the transition to a full breast digital mammography system which is expected to utilize a DICOM interface. A software update which will facilitate the interpretation of MRI is expected to permit the transition to 100 % soft-copy interpretation for MRI as well. The majority of the ten workstations in the radiology department utilize a Macintosh II (Apple Computer, Cupertino, CA) or Quadra 950 system with four monitors (2,048 x 1,536 pixels). The average brightness of the 2,048 x 1,536 pixel monitors is approximately 60 foot lamberts with a refresh rate of approximately 60 MHz. The 34 workstations located throughout the remainder of the medical center are, for the most part, in a two monitor (1152 x 1078 pixels) configuration and use a Quadra 950 computers. The monitors are arranged in a horizontal, ‘fouracross’, configuration. These workstations are located in the patient clinics, emergency room, intensive care units, operating rooms, physician ‘team’ offices, the auditorium, and in the medical media department 181. In addition to the commercial system described above (Loral Medical Imaging Systems), the
Baltimore VA Medical Center, ’ 0 North Greene Sreet, Bait more, Iclar$and 212’31 and University of Maryland Medical School, USA RBM
(1996)
l&3,149-152
0 Elsevier,
Paris
EL Siegel,
Z Protopapas,
B Reiner
et a/
Table I. Modalities and interfaces to the Picture Archival and Communicatiqn System (PACS). Modality Computed radiography Computed tomo&&hy Computed tomography Magnetic resonance Ultrasound Digital fluoroscopy Digital angiography Nuclear medicine Cardiac catheterization lab
,Mandactim Fuji GE Picker Picker ATL Siemens Siemens Picker Phillips
Table II. Image types available on the DHCP imaging system (hospital inforrnation svstem). -
I
Radiology images transferred frism the radiology/nuclear medicine PACS GI end© Bronchoscopy Dermatology Patient photographs Electrocardiograms Intra-operative photographs * Pathology Me&al documents (available using document scanner)
medical center utilizes a second PAC system developed by the Veterans Administration called the Decentralized Hospital Computer Program (DHCP) Imaging system. This image management system enables the Hospital Information System (HIS) to obtain, archive, and permit display of all images generated in the hospital including all of the examinations obtained on and transferred from the commercial radiology/nuclear medicine PAC system (table II). Of the 50 DHCP Imaging workstations which are located throughout the medical center, only three are in the imaging department. The current operating system for these workstations is Windows 95 or Windows NT and they utilize ‘off the shelf Pentium based ‘personal’ computers which are equipped with a 4 megabyte video display card. Unlike the commercial PACS, the DHCP Imaging system supports color images (24 bits). The workstation monitors typically display on a 17 inch diagonal monitor an image at a resolution of 1,280 by 1024 pixels although the workstations can support a variety of monitors up to a 2,000 by 2,500
Jntedce Proprietary (non-standard) int&ce DICOM DICOM DICOM DIISOM ACWNEMA MERGE (non-standard) intcjrface DlCOM Video Capture (8 bit)
pixel display. These workstations are currently utilized primarily for secondary diagnosis (not primary diagnosis by a radiologist), are relatively slower in performance, but are considerably less expensive than those provided by the commercial system (table 111). Both the commercial and the DHCP imaging PAC systems communicate bi-directionally with the Hospital Information System. The HIS is considered to be the ‘master’ database and all physician orders for imaging studies, imaging reports, and patient demographic and other data are entered into this system. The data is then transferred to the commercial PACS enabling ‘paperless’ operation by the radiologists who are able to retrieve old reports and ordering information in addition to prior images for comparison. In addition to providing images for the Baltimore VA Medical Center, the PAC systems serve as a central archive for images from three other hospitals in the state of Maryland. Images are sent to the PACS using ‘Tl’ phone lines, are archived and can be reviewed and/or interpreted using the commercial PACS or the DHCP Imaging system and can then made available for electronic review at those hospitals. The four hospitals currently share a single Hospital Information Sy,stem (HIS) and Radiology lnformatlon System (RIS). Thus, each facility has full access to all image and text information for the veterans who may visit individual hospitals for subspecialty care. The commercial PAC system was installed and became operational at the Baltimore VAMC during June 1993, approximately 5 months after the hospital opened for patients. Just prior to this, a three RRM
(ly96) IEio
18, i
phase prospective study was begun to determine the impact of filmless operation on the medical center [51. The first phase consisted of baseline data collection prior to the transition to filmless operation. Data were collected for a period of approximately 2 months. The second phase of data collection occurred during the approximately 6 month transition period from film based to filmless operation after the PACS was installed, during which images were available both on computer workstations and on film. The third phase of data collection occurred after the transition to filmless operation was complete. These data were subsequently compared and analyzed [6,91.
Results The amount of time required to display a portable chest radiograph and the previous three studies for comparison was measured by direct observation for three operational scenarios (table IV). As would be expected, image display was much faster when images were ‘pre-hung’ by the film library personnel on an alternator in comparison to the case in which the radiologist puts up and takes down the films for each study. Although the use of the computer software display tool (default display protocol) almost halved the display time, image arrangement using the computer workstation was still approximately 30 % slower than manual display of films using a conventional lightbox. The percentage difference between the total time required to both display rind interpret an imaging study using the alternator or conventional viewbox and that required for interpretation using the computer workstation was relatively small (table IV). However, interpretation using a film alternator or conventional lightbox was still slightly faster than diagnosis using a computer workstation. Despite the fact that ‘soft-copy’ interpretation using a computer workstation was found to be somewhat slower than with film, the radiologist productivity actually increased after the introduction of the PACS by more than 50 7%.
Prospective
evaluation
There was an increase in volume (probably unrelated to the introduction of PACS) by more than 50 % without a significant change in the number of radiologists, resulting in this increase in productivity. This seemed to occur without a change in the perceived number of hours worked or percentage of time spent in image interpretation by the radiologists themselves. Factors that could explain this increase in productivity after the introduction of filmless operation include fewer interruptions by clinicians (since they tend to visit the imaging department less often), the fact that old exams and reports are organized and available using the PACS, better ability to share workload among all radiologists, the availability of all images to all radiologists at all times, and the fact that the radiologists do not have to wait for images to be matched and brought for interpretation by the film library personnel 1121. In the computed tomography division, radiologist reading times were found to be approximately 15 % faster with the use of a four monitor computer workstation in comparison with the case in which radiologists hang their own films. This increase in speed seems to be largely accounted for by the ability to rapidly modify window and level settings (eg lung, mediastinal, bone, and liver window/level settings for a thoracic CT) without having to take down and bring up additional films as is the case in a conventional CT reading room [ 111. The almost immediate availability of images for interpretation by the radiologists without waiting for films to be returned by clinicians or sorted and matched by the film library personnel has resulted in
of the impact
of filmless
operation
on the Baltimore
substantial decreases in the time from when an image is obtained until it is interpreted. A study performed comparing image interpretation times at the Baltimore VA with the adjacent University of Maryland demonstrated significant improvement in the number of studies interpreted within a short time or the same day as the study was performed with PACS in comparison to film. This has resulted in the ability of radiologists to interpret studies in a much more timely fashion. A subtle fracture can be diagnosed while a patient is in the emergency room or a retained common bile duct stone can be found by the radiologist with the patient still on the operating room table. The radiologists are able to both draw on and annotate images with appropriate markings or comments to bring attention to a pathologic process. The combination of computed radiography and soft-copy interpretation using the computer workstation has resulted in a significant decrease in the image retake rate from 5 % when using film to RBM
(1996) t&2
18,5
VAMC
below 1 R. The most common reason for image retakes has also changed with the transition to filmless operation from ‘sub-optimal technique’ to improper patient positioning. The ‘lost’ film rate as defined as a study which is not interpreted within a 2 week period after it was obtained has dropped from approximately 8 % to below 1 % with the use of the PACS. Average radiation dosage utilized for portable chest radiographs has dropped by approximately 30 % without a perceived difference in image quality. Investigations with cadaver specimens suggest that similar reductions in radiation dosages may be clinically adequate for other types of examinations as well 1131. Although hospital-wide parameters such as average length of stay and utilization rates of radiology services are potentially of critical importance, it is very difficult to determine the degree to which the use of the PACS has modified these indices. The average length of stay has dropped by over 25 % since the introduction of the sys-
EL Siegel, Z Protopapas, B Reiner et al
tern; however this is probably more likely due to economic and other factors than to the PACS. The degree to which filmless operation has affected this reduction is very difficult to measure. Additionally, the utilization of imaging services per inpatient day and outpatient visit has increased significantly. Similarly it is difficult to demonstrate the degree to which PACS has impacted utilization in comparison with other factors such as a change in the average complexity or acuity of patient care. Preliminary economic analysis suggests that the savings of approximately $650,000 in radiology and nuclear medicine personnel costs, supplies, and other expenses are almost completely offset by the maintenance contract of the system and capital depreciation on the PACS. However, a conservative reduction in the amount of time physicians spend retrieving images of as little as 10 minutes per day would result in savings of $200,000 to $400,000 per year at the Baltimore VAMC. Since the other three affiliated hospitals in Maryland utilize the Baltimore PACS for image archival which saves both radiologist and clinician time, savings associated with the PACS may be considerably higher than these estimates. A more formal economic analysis is currently underway to more precisely determine the economic impact of filmless operation and to develop a model to predict savings at other facilities which could result from the transition to filmless operation. Clinicians who are shared between the film based University of Maryland Medical System and the filmless Baltimore VA Medical Center were surveyed to determine their relative preferences for a conventional film based system in comparison to the PACS. There was a strong preference for PACS (92 %) in comparison to film based operation (3 % with 5 % having no preference). The clinicians indicated that they were more ‘comfortable’ with PACS and that filmless operation required less ‘effort’. They indicated a preference for PACS during teaching rounds predominantly due to improved availability of current and prior imaging studies. The clinicians did not seem to believe that PACS would significantly decrease leng-
th of stay. Only approximately 20 % of clinicians indicated that they had attending the formal PACS training course [151. The majority of those that did not attend the formal training program indicated that they were ‘self-taught’ (53 %) with most of the remainder relating that they had been trained by a colleague (41 %). A study conducted at Baltimore indicated that residents that had been given formal training did significantly better on a formal test of ‘critical’ PACS skills after one week of experience with the system than did those that were self-trained or taught by a colleague. Although the differences between these groups were still significant after 4 weeks, these differences were much less than those found at 1 week. Both trained and untrained groups were able to pass the basic PACS skills test. However, there were persistent differences even at 4 weeks in the amount of time required to use the PACS workstation for image review workstation. These differences suggest that economic benefits are achieved with formal PACS training (at least after 4 weeks of experience) in addition to the clinical benefits. Preliminary results with computer based training have been encouraging although these have not yet been quantified.
Conclusion
REFERENCES 1 Siegel E, Glass H (1992) Purchasing PACS, II 2
3
4
5
6
7
8
9
10
11
Practical experience and in-depth studies of the special requirements for PACS by orthopedic surgeons, vascular surgeons, the operating room staff, and the emergency room staff suggest that a number of improvements to the system and training could result in substantial improvements in the clinical utility of the system [7]. Subspecialty groups have unique requirements for training and location and accessibility of the workstation, monitors, and input devices [14,161. In conclusion, the 3,5 year experience with PACS has been very encouraging with significant improvements in imaging departmental efficiencies, delivery of timely services, clinician and radiologist satisfaction, and operating expenses. 4 RBM
(1996)
18,5
12
13
14
15
16
practical tutorial. S/CAR (Society of Computer Applications to Assist Radiology), p 5 Siegel E (1994) PACS at the Baltimore VA Medical Center. Planning, implementation strategies, and preliminary experience. In: Proceedings of the Korean PACS Society Siegel E, Pickar E (1994) The transition to the jilmless imaging department: early experience at the Baltimore VA Hospital. S/CAR (Society of Computer Applications to Assist Radiology), P5 Siegel E (1994) Parameters required to evaluate a jifmfess imaging system. S/CAR (Society of Computer applications to Assist Radiology), p 508 Siegel E, Brown A (1994) Preliminq impacts of PACS technology on radiology department operations. In: Proceedings of the Annual Symposium on Computer Applications in Medical Cure, 917-921 Siegel ES (1995) Impact of filmless radiology on the Baltimore VA Medical Center. In: Proceedings 1995 Military Telemedicine Symposium. IEEE Computer Society Press Pomerantz S, Siegel ES, I’rotopapas Z, Reiner BI (1995) Experience with PACS in the operating room in a filmless hospital. In: Proceedings of the 1995 Image Management and Communications Conjerence. IEEE Computer Society Press Siegel ES, Denner J, Pomerantz SM, Reiner BI, Protopapas Z (1995) PACS and medical media in a filmless hospital. In: Proceedings of the 1995 Image Management and Communications Conference. IEEE Computer Society Press Siegel ES, Pomerantz SM, Reiner BI, Protopapas Z (1995) PACS in a digital hospital: experience with filmless operation at the Baltimore VA Medical Center. In: Proceedings of the 1995 Image Management and Communications Conjerence. IEEE Computer Society Press Siegel ES (1995) The technology of PACS, a critical assessment. In: Proceedings of the 1995 Image Management and Communications Conference. IEEE Computer Society Press Pomerantz SM, Krebs TL, White CS, Daly BD, Sukumar S, Siegel EL, Protopapas Z, Reiner B (1996) Eficacy of routine reuiezo of liver and bone window settings in thoracic and abdominal CT imaging in the PACS environment. ARRS Siegel ES, Diaconis JD, Pomerantz SM, Allman RA (1995) Making PACS Work. J Digital Imaging, November 1995. Reiner BI, Siegel ES, Pomerantz SM, Allman RA, Fritz S, Hooper F, Protopapas Z (1996) The detection of foreign bodies in soft tissues: a comparison of computed radiography, conventional film, and computed radiography soft-copy. Am J Rudiof (in press) Reiner 81, Siegel ES, Hooper F, Pomerantz S, Protopapas Z, Pickar E, Killewich L (1996) PACS and vascular surgery: clinical impressions and suggestions for improvement. r Digital Imaging (in press) Protopapas Z, Siegel E, Reiner B, Pomerantz S, Pickar E, Wilson M, Hooper F (1996) PACS training for physicians: lessons learned at the Baltimore VA Medical Center. ] Digital Imaging (in press) Pomerantz S, Siegel E, Protopapas Z, Reiner B, Pickar E (1996) Experience and design recommendations for Picture Archiving and Communication Systems (PACS) in the surgical setting. J Digital Imaging (in press)