Kiyonari Inamura

A comparison of conventional screen-film radiography and hard copy of computed radiography in full and two-thirds sizes in detection of interstitial lung disease

This study examined whether hard-copy radiographs produced from computed radiography (CR) images show the subtle interstitial pulmonary disease equally well to conventional screen-film radiographs, because a digital radiography should be chosen for introduction of the digital picture archiving and communication system (PACS) for the new Osaka University Hospital.1,2 Eleven radiologists examined 20 abnormal and 20 control chest radiographs presented in each of three groups: conventional screen-film radiographs and two sizes of hard-copy radiographs made from CR images. This study of digital image quality of chest examinations found that some findings on conventional screen-film radiography images are not reproduced by current CR (2,000×2,000×10 bits in matrix), especially when the experienced radiologists were observed. This finding suggested improvements are needed in CR before CR of chest should fully replace conventional screen-film radiography.

Technology assessment of PACS in Osaka University Hospital

This paper describes a methodology of PACS technology assessment and gives examples of the results of measurement of 24 items of PACS-related situations of image diagnosis systems in Osaka University Hospital before a PACS is installed. These data are to be compared with the data which will be measured after PACS is installed in the new Osaka University Hospital, in order to complete our technology assessment. We propose common variables, units, and conditions of measurement, in order to establish a standard method of data comparison between before and after PACS installation in hospitals at large. We designed our PACS taking technology assessment into account. We do not stop the technology assessment at the efficacy evaluation, because PACS must be more than a tool for radiological practice. We extend the technology assessment into the effectiveness evaluation, so that PACS is a part of radiological practice itself, and diagnostic accuracy, economy and efficiency are the results of PACS operation.

Initial data-element selection for the evaluation of picture archiving and communication system performance

The completely new, hospital-wide picture archiving and communication system (PACS) now being implemented at Osaka University Hospital is described elsewhere in this issue.1 This paper lists the many studies of the department and hospital that were performed before the PACS for the purpose of identifying data elements for use in evaluating a PACS system. A second purpose of the initial data-element collection was to assist in the overall Osaka University PACS design. Selected studies from this work are presented here.

PACS in Osaka University Hospital

To develop the hospital information system, the radiological information system, and the picture archiving and communication system for our new hospital, we analysed the data volume at each step of the flow in our present film-based system. After that, we used a small PACS, and it indicated the problems in it. From the analysis of the data volume of the film-based system, it was found out that digital data should be compressed, and prefetching techniques should be employed for digital PACS. Several types of display terminals had been proved to be necessary for different purposes. An RIS connection was thought to be obligatory to avoid incorrect input of ID on the image. Image input terminals should have edit functions for easy recognition of the image information. Taking account of these requirements for digital PACS, we are developing an actual total PACS.

Developing a new Picture Archiving and Communication System for the new Osaka University Hospital

Osaka University Hospital moved into a new hospital building on the suburban Suita campus in October 1993. A newly developed hospital information system, a new radiologic information system and phase I of a completely new Picture Archiving and Communication System (PACS) also began operating. Work began in 1986 on this PACS. The PACS effort has been guided by one working group and two committees during the last 7 years. A survey of the previous diagnostic and image delivery system was performed as part of the preamble to designing an optimal PACS. Extensive analysis and measurement of pre-existing operational conditions was undertaken. These studies and technical research projects are described in a companion paper in this issue. The phase I hardware installation and initial testing were completed in March 1994. Subsequent phases will build incrementally until the completely new, hospital-wide PACS is realized.

Storage and presentation of images.

The concept of a Picture Archiving and Communication System (PACS) and its state of realization in the world involving USA, Europe and Japan is presented. As examples, MDIS in USA, EurIPACS in Europe and Osaka University in Japan will be reported. The question of to what extent the technical problems in realization of PACS have been overcome and are expected to be overcome in the near future is raised and discussed. As an example of technological difficulties, the problem of rapid exchange of image files between institutions will be mentioned. The position of medical images in the efficacy of diagnosis in hospitals will be also discussed. The integration of PACS with the Radiological Information System (RIS) and HIS is discussed. The technology assessment of PACS is going to be an important theme of study and investigation. An example of quantitative measurement of pre-post PACS/RIS/HIS is included.

Diffusion of digital radiology modalities in the Nordic countries and Japan

The Nordic countries have 23 million inhabitants. About 14 million radiology examinations are performed annually at hospitals and in primary health care. This represents about 600 examinations per 1000 inhabitants per year. Japan, on the other hand, has 125 million inhabitants and annually performs about 200 million radiology examinations at hospitals and in primary health care. This represents about 1600 examinations per 1000 inhabitants per year. The above figures do not include dental X-ray examinations. Between 15% and 20% of all radiology examinations in the Nordic countries and about 5% in Japan are performed with digital modalities such as computerized tomography, digital subtraction angiography, computed radiography, and magnetic resonance imaging. Computerized tomography is the most diffused digital X-ray modality in the Nordic countries with 95,000 inhabitants per scanner while Japan only has 17,000 inhabitants per scanner. For magnetic resonance imaging the difference is almost of the same order. Japan has the same diffusion of magnetic resonance imaging units per 100,000 inhabitants as the Nordic countries have of computerized tomography scanners. The large difference between Japan and the Nordic countries regarding diffusion of digital radiology modalities is explained mainly by differences in the nature and organization of radiology services.

Development and evaluation of oral reporting system for PACS

Experimental workstations for oral reporting and synchronized image filing have been developed and evaluated by radiologists and referring physicians. The file media is a 5.25-inch rewritable magneto-optical disk of 600-Mb capacity whose file format is in accordance with the IS&C specification. The results of evaluation tell that this system is superior to other existing methods of the same kind such as transcribing, dictating, handwriting, typewriting and key selections. The most significant advantage of the system is that images and their interpretation are never separated. The first practical application to the teaching file and the teaching conference is contemplated in the Osaka University Hospital. This system is a complete digital system in terms of images, voices and demographic data, so that on-line transmission, off-line communication or filing to any database will be easily realized in a PACS environment. We are developing an integrated system of a speech recognizer connected to this digitized oral system.

Technology Assessment of PACS: Case Study of the New Osaka University Hospital

PACS, RIS (radiological information system) and HIS (hospital information system) will be rebuilt and operated in the new Osaka University Hospital of 1100 beds which is going to be moved from the present building at down town Osaka to the new building at the another campus. In order to complete technology assessment of our PACS, more than 24 items of measurement to grasp present situation of PACS related performance in the present hospital were carried out. Those data will be used to compare with the result which will be measured after the new PACS is operated in the new hospital. Definitions of variables, parameters, formulae and methods of measurement are common or same as possible between before and after new PACS operation. These definitions are carefully selected and prepared for the purpose of generalization or methodology in technology assessment of PACS in hospitals at large here in Japan. This paper describes the philosophy, methods of our technology assessment and some result of the survey of present situation.

Oral reporting system in an IS&C environment

An radiologic reporting system by means of oral presentation in an IS&C (Image Save and Carry) environment has been developed and tested. The rewritable and compact magneto- optical disk (MOD) according to the standard specification of IS&C filing format is employed to store oral diagnostic reports together with read radiologic images. The MOD of 5.25 inches in diameter has 600 MB memory capacity. Advantages of the system are: simultaneous retrieval of oral reports and the images which a radiologist interpreted, and capability of media circulation in addition to the function of filing. Thus the MOD in our IS&C environment has a multimedia function of both off-line communication and filing. When medical images are interpreted and oral presentations are registered, the digitized oral reports and the digitized images are filed to the MOD automatically. Referring physicians can get the diagnostic reports by oral speech and can see the images at the same time in front of personal computer. Furthermore, integration with a voice recognition machine is being tried in our experiment.