Kazuo Inamoto

Multi-media PACS integrated with HIS/RIS employing magneto-optical disks

A multi-media magneto-optical disk filing system which stores the voice of image interpretation and order of image diagnosis issued at physicians departments has been developed. The advantages of these 5.25 in., 600 MB disks are rewritability and compactness; they are applicable to circulation media as well as filing media inside hospitals. In this paper, the status of magneto-optical disk (MOD) application to medical images involving standardization activity is briefly introduced. Results of system analysis of the hospital at Osaka University School of Medicine are presented, and the design of HIS/RIS/PACS and role of MOD through HIS/RIS/PACS are described. The result of the experiments -- oral reporting accommodation, together with medical images, interchangeability check, and hand carry acceptance check -- are also reported. Technology assessment steps and future development are further discussed in terms of speed, security, file integration, and operability.

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.

Trial of PACS employing magneto-optical disks

Rewritable and compact media of magneto-optical disk (MOD) was firstly employed by us to store medical images such as digital X-ray films. The purpose is to test functions of communication media or circulating media as well as of filing media. Another feature of our trial system is to involve voice recording module for diagnostic reports. Method of clinical application and development approach of our PACS with MOD is discribed in this paper. Technology assessment of our system is also briefly descussed in terms of cost-effectiveness and security problem.

Oral diagnostic reporting and synchronized image filing using magneto-optical disks

An experimental radiologic reporting system has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is applied to storing medical images with oral diagnostic reports of these radiologic images. The disk is 5.25 inches in diameter, has 600 MB memory capacity, is erasable, light and compact. Advantages are simultaneous recording of radiologic images and their oral reports by radiologists, and application to circulation of media inside the hospital as well as to filing of medical images. The MOD has a multimedia function of communication and filing. When medical images are taken and stored, oral interpretation by radiologists can be simultaneously added. Physicians can get information of the images and their reports by oral speech at the same time in front of computer workstation. Furthermore, integration of a voice recognition capability is now being undertaken.

Low-dose x-ray imaging GLG: restoration by Kalman filter

The present study was designed to monitor novel ideas in the acquisition and manipulation of data in an X-ray imaging system. A grid was sandwiched between two cascaded imaging plates (Ips). Using a fan-beam X-ray tube and a single exposure scheme, the two Ips, respectively, recorded gridless and grid (GLG) type information of the object. Referring to the mathematical model of the GLG technique, it was explained that the collected data associated with the gridless IP was of high (S/N) and suppressed scattered components. Based on this assumption and using a Gaussian convolution kernel representing the effect of scattering, a technique was proposed to estimate scatter parameters of the GLG plates. Then, a Kalman filter was developed to restore noisy blurred images of the GLG techniques using the Ips data and estimated parameters. The results are shown for both the computer simulated and real X-ray phantom data.

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.

Sensing of small signals on CRT-displayed medical radiographs after A/D conversion

Abstract The paper describes an experimental evaluation, by ROC analysis, of displayed CRT images after digitisation of analogue medical radiographs. Two types of images were used in these studies: (1) images of 2 mm diameter beads, and (2) images of 2 mm diameter cavities. The psychophysical experiment was carried out by obtaining ROC curves based on signal detection theory. Detectability was evaluated as the ‘area under the ROC curve’. It was found that the detectabilities of images on the CRT were significantly lower than those of the original images. As for the images of bead signals, the ‘areas under the ROC curve’ were 0.91 and 0.70 for the original images and the digital images respectively. However, the ‘area under the ROC curve’ could be improved to 0.84 or 0.80 by a multi-cycled display going through 2 or 4 cycles of contrast enhancement in the studies of bead images. The ‘area under the ROC curve’ of the cavity images was better than that of the beads.