Applied Radiology

New management procedures are needed to handle the adoption of a picture archiving and communication system (PACS). This article describes a team approach to managing the tasks associated with a PACS specification, installation, acceptance, training, and quality assurance program.

Picture archiving and communication system (PACS) technologies have matured to the point that PACS is being installed in many institutions throughout the world. Once funding sources for the equipment have been found, radiology departments are moving forward quickly and usually spending several million dollars in an effort to reduce their reliance on film. In order to be successful, a PACS installation must be managed throughout all the phases of introduction, from early planning through installation, evaluation, training, and clinical use.

Implementation management is crucial for the success of a PACS installation. Faculty and staff at the Shands Hospital at the University of Florida have dealt with PACS issues for several years and have developed a PACS installation checklist with procedures that must be followed for each addition to the network. These procedures, which are listed in table 1, can be used in both a phased implementation and a "turn-key" installation of PACS and are described here in detail.

Communications

Communications are important throughout the PACS adoption process. Reluctant users can cause a system to fail, either inadvertently or with malice. It is recommended that users

be included on several PACS implementation teams, as described briefly in table 2.

The oversight team sets priorities, evaluates needs for each potential project, sets goals, specifies requirements, plans the implementation, monitors each stage in the process, and assures that all tasks are being completed.

The operations team is the "working group" that arranges for facility renovation or construction, oversees installation, performs acceptance testing, and assures that an installation is complete.

The training team organizes appropriate training for all users, including radiologists, technologists, clerks, and service personnel. This group manages the creation of appropriate documentation and maintains records of those users who have been trained for the use of various equipment.

The service team manages all aspects of maintenance and quality assurance for the systems. They are responsible for maintaining quality assurance records and asset inventories for each component of the system.The most important aspect of these teams is that they include personnel from all areas of radiology and information services. If service is provided by an outside firm, they are included on the project from the beginning. It is very important that everyone be involved in the entire process of PACS implementation to achieve acceptance of the technology.

Specification

There are several elements of specification. First, the expected work load must be quantified to estimate correctly the size of archives, the bandwidth for the network, the number of workstations, and requirements for the workstations in terms of functionality and performance.1,2 Second, the design of work areas to support PACS must be considered. Third, acceptance criteria must be established.

Many institutions underestimate the archive and workstation storage requirements as well as the number of workstations needed for smooth and efficient operation. In a teaching hospital, for example, it is difficult to share a workstation between the functions of clinical interpretation and teaching or rounds with clinicians.

In a film environment, viewboxes or scopes may have been shared among several radiologists. Conflicts can occur when multiple users need to view images on a shared workstation. Perhaps this is because, in the film environment, a radiologist can lift an individual film from the viewbox to view in another location. It is important to survey the area designated for a PACS and understand the requirements for the system. The functionality of workstations varies widely among vendors. The users must communicate clearly their requirements for functionality of a workstation to be sure they purchase a system that meets their expectations.3

The PACS should improve the work load of all users. In practice, this usually includes technologists and radiologists. Of course, other physicians, nurses, and file clerks also will need to use the system, but the primary users of the PACS are the technologists who will be acquiring digital images instead of film and the radiologists who will be dealing with soft-copy interpretation.

The oversight team described in table 2 typically should analyze the steps required to perform a radiology study and attempt to streamline the process using the new technology. The importance of interfacing a PACS with a radiology information system (RIS) or hospital information system (HIS) cannot be overstated. It takes time to enter data when a study is performed that adds to the technologists' work load.

With a properly configured RIS interface to the PACS, the selection of the appropriate patient can be made from a worklist that will automatically enter all the patient demographics as well as study information and relevant clinical data. When data entry is eliminated, databases used to locate a completed PACS study are correct and complete and queries can be performed successfully. With manual data entry, extra time is required to perform the study and errors will be introduced.

The design of work areas should be considered carefully, especially when placing workstations in existing reading rooms and PACS acquisition equipment in existing facilities. Glare arising from viewboxes and scopes severely degrades image quality on workstations. Room lighting should be indirect or directed in a way to reduce or eliminate glare. In many traditional reading rooms, lights are turned off. In a workstation environment, some lighting may be needed to compensate for the elimination of the light from viewboxes.

Workstation furniture must be chosen carefully to accommodate the fairly large PACS monitors, input devices such as keyboards and pointing devices, dictation equipment, RIS/HIS monitors, ICD9 coding books, notes and request forms, etc. In addition, since the workstations will be used by many people, adjustable furniture is recommended.

PACS acquisition equipment, such as computed radiography units, digitizers, and secondary capture devices, must be placed in locations where they are convenient to use without impeding the workflow. Large monitors added to many existing rooms where ultrasound or fluoroscopy examinations are performed may not leave enough space to maneuver with a stretcher or wheelchair.

The oversight team is responsible for setting the acceptance criteria for the system. Acceptance criteria should include definitions of adequate image quality, ease of use, appropriate range of functionality, and performance expectations. If multiple vendors are involved in the system, interactions among them must be defined.3 The objective of specifying acceptance criteria is to reduce the element of surprise when a new system is delivered as well as to provide a contractual basis for acceptance of and payment for equipment. This means the oversight team must do a lot of homework before issuing a contract.

Installation

The operations team is responsible for the details of the installation. This includes renovation and construction, working with the vendor to assure adequate power, air conditioning, and communication network connections, and verifying that the installation meets the codes and rules of the institution.

If the digital system is an addition to an existing clinical system, scheduling for installation is a major concern. Normally, it is preferable to run a new system and an old system simultaneously while the operational and technical problems with the new one are identified and solved. In this way, new technology can be phased in with a minimal disruption in clinical service.

When possible, a new system should be introduced in a nonclinical environment so that training and testing can be performed; then, when the system is ready, it can be put into clinical use. This is possible with some technologies, such as new workstations; however, it is more complicated with others, such as a digital fluoroscopy unit added to an existing RF room. If multiple units are being installed, one can be installed initially and used until problems are worked out and there is a general agreement that the technology is ready to be used; then, the other units can be installed to minimize downtime.

Acceptance

Testing a new installation prior to acceptance is crucial.4 No matter how precisely a system has been specified, some criteria can be subject to interpretation of meaning. Once a system is in place and being used, unanticipated operational issues may appear. Never underestimate the ability of the user to find a new, unsupported way of using the system. Users should be involved in the acceptance testing so that the technology experts can spot these deviations from intentional use and either adjust the way the system is used or adjust the system to support the desired use. The operations team is assigned the task of organizing and documenting acceptance testing.

In addition to testing the system to ascertain that it meets functional specifications, a rigorous stress test may identify any tendencies toward failures. The system should be tested to and beyond the limits of its performance. For example, a system should be pushed beyond the highest bandwidth supported or a workstation's disk space should be filled beyond its storage capacity to see what happens when these limits are exceeded.

If the equipment performs acquisition, every type of image that can be acquired should be tested prior to acceptance. If an institution performs a study that is not anticipated by the acquisition equipment manufacturer, it is important to be sure that the study can be performed after the equipment is installed. For a simple and common example, many film digitizers do not easily scan 7" ¥ 17" films, which are used commonly in extremity and spine radiography.

Another common problem is the inability of a workstation to post scout images from all CT and/or MR manufacturers correctly. Both of these examples pose clinically important problems, yet they often are difficult to solve.Maintaining records of the results of the acceptance tests will set the baseline performance and functionality of a system for comparison during future quality assurance programs.

Training and workflow changes

The training team is responsible for the management of user documentation and training. Each user of the system must be trained and certified as a qualified user of the system. It is advantageous to maintain documentation of all users trained for each component as well as to keep a record for each individual. In the case of a technologist, the ability to work with PACS equipment may enhance his or her professional standing; in the case of a radiologist, proof of adequate training may be required in cases of litigation.

As is common in the adoption of all new technology, it will be important to identify a person or persons who can train trainers and users. Training must be performed for all employees, and in many departments with 24-hour service, this includes employees who work at night and on weekends. After an installation is complete, continued training may be required if the environment supports rotation of personnel through clinical areas; each rotation cycle must be trained, and even retrained, if the cycles are more than two or three months apart.

At some point, all equipment in a radiology department will require service, and PACS is no exception. In order to achieve rapid resolution of problems that will arise, some form of in-house service almost certainly will be needed. This could be as simple as a few technologists identified and trained to troubleshoot problems or as complex as a complete in-house service organization. Personnel designated to maintain or service the equipment must be trained, usually by the manufacturers of the equipment.

As new technology is introduced, departmental operations will change, sometimes in unexpected ways. For example, when digital archives and fast network access to images are available, a department may opt to be filmless. In an area such as computed tomography, without the need to print film, there may be a tendency to produce more images. This, in turn, may extend the length of time it takes to perform a patient examination, increase the capacity needs of an archive, and increase the performance requirements for a workstation.

Once a new system is introduced, unanticipated opportunities to exploit the technology beyond its original intentional use may arise. For example, when workstations become the display device of choice and film is no longer produced, more people will need to view the images on the workstation. Additional workstations may be needed to support new users. If the workstations are the method for display of images for teaching, the workstation may have to be updated to support additional monitors for instructing large groups in a "rounds" configuration.

Another example of an operational change that will occur with the installation of PACS is the organization of images on the display. In many institutions, films are hung on viewboxes or scopes by technologists, residents, or film library personnel who assure that all images are oriented correctly and are organized logically. On a workstation, digital images from a film digitizer or computed radiography unit usually appear in the orientation and order in which they are acquired. Many workstations do not have the capability to reorder images easily, and the rotate/flip functions may be slow. Plans will have to be made to solve these problems and avoid reducing the productivity of the radiologist.

In a filmless environment, it may not be desirable to deliver all the images in a multi-image study to the referring clinician. If only selected images will be printed or sent to referring physicians, the radiologist will have to change his or her work patterns to make the selection and print or send them. In the non-PACS environment, technologists and film file clerks are responsible for printing and distributing studies.

Quality control

A system must be established to assure proper operation of the PACS and the quality of the clinical images. Every link in the imaging chain must be periodically checked and documented as being operational. This includes acquisition, transmission, display, printing, and archiving.5 Table 3 lists the tasks associated with the quality assurance program used at Shands Hospital at the University of Florida. The service team is responsible for organizing and monitoring quality assurance.

Image acquisition tests are performed at the beginning of every day to assure that images can be sent successfully to the appropriate PACS workstation(s) and archive. This simple test can be performed by the technologists who acquire a phantom image and send it to PACS, then check to be sure it was transmitted to the appropriate location. These tests are performed on every direct digital device, such as CT, MRI, and ultrasound units.

Quality control of the devices themselves are the responsibility of physics personnel. In the case of PACS image-producing equipment, such as computed radiography units, digitizers, and secondary capture devices, a phantom image is acquired or scanned, sent to the appropriate output device (either a workstation or a printer), and examined visually to verify that the image quality looks acceptable from an objective standpoint and that the network routing was performed correctly. On a monthly basis, a more complete quality control procedure is performed, wherein a series of phantom images are acquired and analyzed for contrast range, resolution, and linearity.

Transmission checks are performed as part of the acquisition tests on a daily basis. When new equipment is added to a system, all routing is tested to be sure that the device can communicate with all other devices. This test also is performed after all equipment upgrades.

The infrastructure is tested to be sure that all DICOM servers and processes that handle images are working correctly. This is a function that can be automated. Computers that are part of the PACS installation at Shands Hospital at the University of Florida cross-check each other to ensure that they are all up and running. Furthermore, on each computer, an automatic check of all processes is performed every ten minutes.

In addition, the directories associated with any store-and-forward image handling are checked for images that have been present longer than expected. Disk space is monitored to be sure the capa-city is not exceeded. If any error conditions exist, the systems call a pager with a coded message describing the problem, the severity of the problem, and the computer associated with the problem. Service personnel can refer to intranet documentation for help in troubleshooting problems. The goal is to be informed of a problem by a computer before a user notices a failure.

Output devices are checked objectively on a daily basis by visual inspection. On a monthly basis, digital phantoms displayed on workstation monitors are measured with a photometer to quantify luminance. Phantoms are printed on laser cameras and paper printers and measured for adequate gray-scale representation. Resolution and linearity also are measured monthly on both workstations and hard-copy devices.

Archive storage should be checked automatically on a daily basis. At Shands Hospital, the archive software prepares a list of studies performed the previous day for each section in radiology and faxes the list to the technologists in each area. The list is compared against the study log for the previous day to be sure all studies were archived. In addition to the archive check, it is advisable to check the database system periodically for adequate table spaces, disk space, and resources. A weekly check will avoid a panic situation when the database exceeds its initial size setup.

Conclusion

PACS is being embraced energetically by a large number of institutions, and the trend is expected to continue and grow in the coming years. The issues associated with selection, installation, acceptance, training, servicing, and assuring quality have not been well-defined. The program described here is one developed at Shands Hospital at the University of Florida in response to problems encountered during various PACS installations. It is one that will help assure a smooth and successful transition to a digital environment. AR

References

1. Honeyman JC, Messinger JM, Frost MM, et al: Evaluation of requirements and planning for picture archiving and communication systems. Radiographics 12(1):141-150, 1992.

2. Honeyman JC, Huda W, Frost MM, et al: PACS bandwidth and storage requirements. J Dig Imag 9(2):60-66, 1996.

3. Honeyman JC, Arenson RL, Frost MM, et al: Functional requirements for diagnostic workstations. SPIE Medical Imaging 1993: PACS Design and Evaluation 1899:103-109, 1993.

4. Honeyman JC, Frost MM, Staab EV: PACS component testing: Beta and acceptance testing. SPIE Medical Imaging 1997: PACS Design and Evaluation 3035:405-412, 1997.

5. Honeyman JC, Jones D, Frost MM, et al: PACS quality control and automatic problem notifier. SPIE Medical Imaging 1997: PACS Design and Evaluation 3035:396-404, 1997.