Abstract
We describe the implementation of a simple data interface between a radiology information system and a computed radiography system, using personal computers and standard software. The radiology information system developed in-house, runs in a local area network of personal computers. The computed radiography system is connected to a picture archiving and communication system. We have implemented a software data interface on a microcomputer, allowing automated transfer of patient data from the radiology information system program to the computed radiography scheduling program. The interface adds essential information used by the picture archiving and communication system to handle worklists, routing, and archiving algorithms. We have improved the user interface, shortened the scheduling time, enabled coherence of data bases, and eased the use of computed radiography and exam routing in picture archiving and communication system. We have been using this interface for more than 1 year without difficulties. This custom solution addresses the problem of interconnecting existing equipment, avoiding proprietary restrictions or the lack of effective standards. This approach can be applied to any radiology environment that uses personal computers.
PS (1997): The system was in operation between 1993-1996, when the PCR-901 system was retired from service. This macro approach has been applied to other settings afterwards.
Introduction
The radiology information system (RIS) is a repository of validated patient, clinical, and administrative information, with connections to data or image handling equipment and to the hospital's information systems. In departments in which radiographic studies are performed digitally by using computed radiography (CR) an effective data path between the RIS and the CR is needed [1, 2]. Such an interface would avoid problems of redundant scheduling of patients, typing errors, and inconsistencies between CR and RIS data bases.
CR systems are nearly closed systems that can be attached to a picture archiving and communication system (PACS) of the same manufacturer, but they are difficult to interface to other equipment. In the usual CR implementation, patients' demographic data must be re-entered by retyping information at a dedicated terminal or using a magnetic card recorder or a barcode printer-reader system. Inaccurate data are automatically transferred to the PACS.
This paper, although not presenting revolutionary findings, describes a method of how to minimize errors using the CR system by taking data directly from the RIS. The result demonstrates that this connection really cuts down time and facilitates the delivery of patient information to the CR systems.
Materials and Methods
The radiology department of our hospital has all imaging techniques connected to a PACS. We are use CR in 99% of our radiographic studies; 72% of all our diagnostic imaging procedures [2, 3].
The RIS is a multiuser, X-base compatible, software package running over an Ethernet local area network (LAN) of low-cost PC-compatible microcomputers running MS-DOS and NetWare (Novell, Inc., Provo, UT). The RIS, with seven attached PC, handles patient identification, registration, scheduling, diagnostic coding, reporting, teaching files, and statistic reporting. It was developed in-house by one of us and has been in use since 1987, being easy to customize. The RIS is also connected to the hospital's information system.
The CR system, a PCR-901-Graphics (Philips Medical Systems), was installed in October 1988. The main CR computer (PCS), running UNIX System V-release 3, uses Unify data base software to keep track of patients, examinations, and scheduling data. The user interface to schedule patients and examinations is based in a PC, called the "reception terminal" that runs a graphic program over GEM (graphic environment manager, Novell Inc, Provo, UT). The PC program talks to the UNIX server by serial communications, issuing standard query language (SQL) commands. The user types the patient's data in empty fields and selects examination options by pointing and clicking with a mouse. Once processed, all radiographic images are archived on CR optical disk. Since 1991, the CR has been connected to a PACS (CommView, AT&T-Philips Medical Systems). All in-patient images, including CR, are archived in the PACS optical disks. All imaging studies flow to PACS and are distributed to eight diagnostic or review workstations.
To establish the RIS-CR interface (Fig. 1), we have devoted a PC-compatible microcomputer with an Intel 386-SX microprocessor and 5 megabytes of random access memory (RAM). The physical connections are set to the LAN by a thin Ethernet adapter and to the CR server by a standard serial port (RS-232). The computer runs under MS-DOS 5.0 (Microsoft Corporation, Redmond, WA) and DESQview-386 v.2.2 (Quarterdeck Office Systems. Santa Monica, CA). DESQview is a popular MS-DOS program that will run several MS-DOS, GEM, or Windows programs in different screen windows simultaneously (multitasking).
Fig
1. Detailed configuration of interface
between radiology information system (RIS) and computed radiography system
(PCR 901).
PACS=picture archiving and communication
system, PIP=PACS-CR interface processor, HIS=Hospital's information system.
In our setup, it allowed side-by-side operation our RIS software and the CR's reception terminal application. On start-up, two windows are opened: one running the CR software without any modification and the other running the RIS software. The user can switch between both programs by using the mouse or by one keystroke ('plus' key) and use the computer normally. Data appearing in one window can be cut and pasted to the other window. All processes, including opening, switching of windows, and data transfer, are fully automated by a macro. The interface can be operated without special training by any of our clerks, nurses, or technicians.
Demographic data including the patient name's, sex, and birth date, inpatient/outpatient status, worklist destination, and examination identification code are forwarded from the RIS to the PACS. The RIS program was slightly modified to adjust data formats to those accepted by the CR or PACS system: the date is reversed from the European day-month-year format to American month-day-year format. Double family names, or complex names, are joined with hyphens (Fig 2).
Fig
2. Scheduling program screen.
The user interface has been translated to Catalan and Spanish.
PACS image and data workstation's destination are assigned to function keys. The function keys are labeled to allow to fill the fields to fill with a single keystroke. On the PACS side we have developed a method that allows us to build differentiated PACS worklists according to the requesting departments, medical specialities, or ward, allowing selective reviewing and reporting for every radiologist, and efficient prefetching of CR images in CommView PACS (Piqueras J, Carreņo J-C, unpublished data).
When a trigger function key is tapped a series of commands is automatically performed (Table 1). The end of the sequence yields to a complete CR examination and patient's scheduling with full RIS data preservation and main PACS pre-fetching information added. To complete our system, we are developing a direct RIS-PACS interface following American College of Radiology-National Electrical Manufacturers Association (ACR-NEMA) protocol, version 2.0 [4].
Table 1: Main steps in the RIS-CR macro sequence.
|
Two
Windows (RIS and CR) are already opened by Desqview *: User required actions RIS: Radiology information system, CR: Computed Radiography, PACS: Picture archiving and communicating system. |
Results
We have been using our RIS-CR interface implementation 24 hr per day for 18 months without difficulties. Because we can use a single computer for RIS and CR procedures, we avoid moving between computers and keyboards. As data do not need to be retyped for new CR patients, mean scheduling time has been reduced from 75 sec to 30 sec per patient. Typing errors have disappeared almost completely. Duplication of patient's records is avoided by extensive data validation routines in the RIS system. The CR data base is now coherent with the RIS data base; The CR data base system is quite fragile and we have lost part of the patient's data base several times after system failures. With our interface, information is always preserved in the RIS, without the need for retyping. As most patients have radiographic examinations, frequently as the first examination, reliable and validated data for patient are correctly passed to the PACS with their images.
A single error in the CR data requires changes on CR, optical disk, PACS server, remote PACS workstation, and film hardcopies (if any). These correction procedures can take between 5 to 10 min per patient. Furthermore, if inpatients are incorrectly scheduled as outpatients, the PACS will use improper routing, archiving, and active data base deleting algorithms.
Including all user's groups, 19 people are handling the scheduling of CR examinations. All were trained in less than 30 min to use the RIS-CR interface. User acceptance is excellent; operators find the avoidance of retyping data and the shortened procedure time as rewarding. Feedback from users helped us to refine the interface during the first 2 months of use.
Functionally, the RIS-CR interface system is very reliable. For the CR technical service staff, the implementation is transparent: their software and equipment remain unchanged. If the system freezes, with no activity on screen or at the keyboard, as happened in the very first few days after bizarre key sequences, it can be easily turned on again just by resetting the PC, as it was designed to be auto-starting.
As functional standards are still being established [5], it is difficult to setup an interface between CR systems, RIS, and PACS. Our CR computer supports a dialect of the standard query language SQL but it was undocumented, and we will need to develop an new graphic user interface. Our implementation reduced the development time to few days, uses the existing software, and avoids the risk of corruption of the CR's data base by software misbehaving.
Conclusion
Integration of computer systems in radiology is mandatory for cost-efficiency and to avoid errors in the complex chain of data systems of a modern department. The cost of locating examinations when inaccurate information is entered on a PACS or CR optical disk is significant. Interfacing RIS and CR, usually proprietary or undocumented systems, could be very costly in terms of equipment and manpower. The technological life-cycle of software and computer equipment is so short that extensive custom developments are not usually cost-effective.
The use of PC microcomputers helps to solve daily problems thanks to the number of software packages and tools ready available. The solution provided can be applied, with local modifications, to any radiology equipment, or imaging system, that uses PC microcomputers. The PC could act as a gateway between incompatible systems. Although this solution is not as neat as a full RIS-CR integration, the cost of development is only a fraction of the former, and it can be setup in a very short time.
References
1. Lucaya J, Carreņo J-C, Jiménez F. Radiografía computerizada en pediatría: seis meses de experiencia clínica [Computed radiography in children: six months experience]. An Esp Pediatr (Spain) 1989;31:317-321
2. Carreņo J-C, Piqueras J, Lucaya J. Utilización de un sistema de radiografía computarizada en un hospital pediátrico [Use of computed radiography in a pediatric hospital]. Radiologia (Spain) 1992;34:79-83
3. Piqueras J, Carreņo J-C. The PACS project in Barcelona: status in 1992. EuroPACS Newsletter 1992;7:25-28
4. ACR/NEMA 300-1988: Digital imaging and communications. Washington, DC: National Electrical Manufacturers Association, 1989
5. Bidgood WD, Horii SC. Introduction to the ACR-NEMA DICOM standard. In: Honeyman JC, Staab EV, eds. Syllabus: a special course in computers for clinical practice and education in radiology. Oak Brook, IL: RSNA Publications, 1992:37-46
Acknowledgments:
We thank Mr Manuel Ovelleiro and Mr Juan Zas (from Philips Medical Systems, Spain) for their technical contributions.
Finantial Statement:
This work has been done in the framework and financial support of the digital radiology project of the Catalan Office of Health Technology Assessment (COTA), Departament de Sanitat, Generalitat de Catalunya, Spain.
Trademark disclaimer: (*)
Intel, Novell, Netware, Microsoft, MS-DOS 5.0, UNIX System V, DESQview, GEM, Windows, CommView, Philips, AT&T are proprietary, or registered trademarks, of their respective holders.
Correspondence to:
Dr. Joaquim Piqueras
Pediatric Radiology Department
Hospital Materno-Infantil Vall d'Hebron
Autonomous Univ. of Barcelona (UAB)
P. Vall d'Hebron, 119-129
08035 Barcelona (Spain)
