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At least 37 records · Page 2Linked to original sources

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.

Image Processing, Computer-Assisted↗

IS & C system and file protection mechanism.

This paper reports a new extension of IS & C (Image Save And Carry) project. Because IS & C is an off-line system and requires full compatibility so as to enable medical data interchange with ease among hospitals and clinics, specifications that are indispensable for compatibility have been standardized by the IS & C committee. The IS & C system is supposed to be used in medicine, so the file protection mechanism for the security of the recorded files has been also developed. The characteristics of IS & C volume and file structure and the second national project being carried out in National Cancer Center Hospital are briefly explained as well.

Computer Communication Networks↗

IS & C implementation of an image workstation.

The Image Save & Carry (IS & C) 5-inch magneto-optical disk system was introduced to a PACS image workstation so as to exchange digital image data between two independent PACS modules. The results showed that it was possible to connect two different PACS modules by off-line data transmission. Also, the IS & C standard software proved to be of high speed read/write performance for several data files on an image workstation. However, when the IS & C is implemented to the high resolution real-time digital radiography system, an image compression standard will be required to expand its capacity.

Animals↗

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.

Education, Medical↗

Development of medical information transfer system using personal-agent optical disks.

The establishment of a better local area medical centre containing hospitals and clinics is thought to be a very important issue. The medical information system, which should be accepted by both hospitals and clinics, has been studied using graphic user interface (GUI) and a three dimensional structure. Our system files medical records and blood examination data as well as diagnostic images, which may be the first attempt in the world. It has been favourably evaluated by physicians through clinical evaluation.

Evaluation Studies as Topic↗

Optical recording of trisynaptic pathway in rat hippocampal slices with a voltage-sensitive dye.

Changes in membrane potentials were recorded from rat hippocampal slices with a voltage-sensitive dye using a real-time optical recording system, which had high spatial resolution of 128 x 128 points with a high time resolution of 0.6 ms. Serial excitatory propagation was recorded in the dentate gyrus. CA3 and CA1 after stimulation of the perforant pathway, and the optical signals were clearly divided into two components in the dentate gyrus adjacent to the stimulus site. The slow component was suppressed in Ca(2+)-free solution, but the fast component in the molecular layer was not affected. However, the application of 1 microM tetrodotoxin fully abolished both components. These results suggest that the fast and slow components mainly reflect Na(+)-dependent action potentials and excitatory postsynaptic potentials, respectively. The excitatory response duration in the stratum radiatum of CA3 was significantly longer than that in other hippocampal areas. The long-lasting excitation in CA3 is probably related to the CA3 associational projections, because direct stimulation of CA3 pyramidal cell layer also produced similar results. The long-lasting dendritic excitation is probably important to integrate synaptic transmission and may be related to epileptogenesis. When long-term potentiation was induced by a tetanic stimulation (100 Hz for 1 s), the onset latency in the stratum radiatum of CA1 was reduced to as much as 65%, suggesting an increase of excitatory propagation. The analysis of the spatial-temporal optical signals contributes to understanding information processes in the hippocampus, related to learning and memory including long-term potentiation.

Animals↗

Universal interface for exchange of medical images via magneto-optical discs.

Digital images are the ever-growing basis of modern medical imaging and treatment. Despite the advent of the DICOM 3.0 standard for medical image communication it still requires cumbersome efforts to export images from imaging modalities to other computer systems. This is true especially for smaller institutions, which often have limited resources for standardized image transfer. To gain access even to these data we developed an exchange interface on the basis of magneto-optical discs (MO-discs), as they are usually available in most of the imaging modalities in use today. Unfortunately images on MO-discs are usually stored in formats specific for each manufacturer. Therefore special routines to access the data on MO-discs had to be developed for each company or even each scanner. Over 10,000 CT and MRI images including their header information from different General Electric and Siemens scanners were extracted successfully from MO-discs. The interface proved to be reliable and easy to handle by technicians. Support of additional manufacturers and of the DICOM 3.0 standard are work in progress.

Computer Communication Networks↗

CARDIOMEDIA: a communicable multimedia medical record on Intranet and digital optical memory card.

As part of French health reform, French physicians were computerised by the end of 1998. A specific Intranet network will be used to communicate medical data between the health professionals. The objectives of the CARDIOMEDIA project were to develop and evaluate the feasibility of a coronary multimedia data record stored on an optical card and communicable on Intranet within the hospital. Patients treated by angioplasty at the University Hospital of Rennes participated in the experiment. In general, patients are treated in the University Hospital and are followed up by another health care provider closer to their home. The patient leaves the University Hospital with his card, which is directly available elsewhere for emergency or for consultation. This approach is assumed to reduce the number of examinations and to offer a better patient follow-up. The CARDIOMEDIA card is a specialised record including various data types: text, images, image sequences of coronarography and ECG signals. For this purpose an optical card with its large memory is very convenient. We used the DICOM format for image exchange and management. It is combined with CARDIOMEDIA specific compressing software. For the multimedia record the HTML format and web Intranet method are chosen. This provides an intuitive interface which can combine various data types and helper applications like a DICOM image viewer.

Angioplasty↗

The DICOM image formatting standard: its role in echocardiography and angiography.

Both echocardiography and angiography have traditionally used analog media for long-term storage, but increasingly there is the desire to develop digital storage and exchange methodology. Before digital storage can become a reality, though, standards must be agreed to by the vendor and user community to ensure global intra operability of medical instrumentation. To this end, the National Electrical Manufacturers' Association and various professional organizations from around the world have collaborated to develop the DICOM (Digital Imaging and Communications in Medicine) image formatting standard. This standard specifies the exact way in which digital images are exchanged between instruments, either using a network or storage medium, and distinct standards have been developed for angiography and echocardiography. In angiography, only gray scale images are considered, whereas in echocardiography several different types of image formats are allowed to account for color Doppler echocardiography. Distinct standards have also evolved for disk-based storage. For angiography, only storage on the writable CD-ROM is allowed, whereas echocardiograms may be stored on re-writable magneto-optical disks, floppy disks, and CD-ROMs. Only lossless compression is allowed in the angiographic standard, whereas echocardiography allows the use of the JPEG (Joint Photographic Expert Group) lossy compression algorithm. Currently, all major angiographic and echocardiographic vendors have agreed to support the DICOM standard, and products are beginning to appear, first with disk-based storage but increasingly with network-based exchange of image data.

Coronary Angiography↗

Integration of a picture archiving and communication system with videocapture and computed radiography in a dental hospital.

A method for the integration of a picture archiving and communication system (PACS) at Kyushu University Dental Hospital with radiological information (RIS) and hospital information (HIS) systems is described. CT, US and DSA from different manufacturers were integrated by videocapture and then subsequently integrated with computed radiography (CR) by means of DICOM. The approximate amount of data stored each month on optical discs is 2 GB. The system does not incorporate intra-oral radiography.

Angiography, Digital Subtraction↗

Simulation of radiation effects on three-dimensional computer optical memories.

A model was developed to simulate the effects of heavy charged-particle (HCP) radiation on the information stored in three-dimensional computer optical memories. The model is based on (i) the HCP track radial dose distribution, (ii) the spatial and temporal distribution of temperature in the track, (iii) the matrix-specific radiation-induced changes that will affect the response, and (iv) the kinetics of transition of photochromic molecules from the colored to the colorless isomeric form (bit flip). It is shown that information stored in a volume of several nanometers radius around the particle's track axis may be lost. The magnitude of the effect is dependent on the particle's track structure.

Biophysical Phenomena↗

Nonvolatile read-out molecular memory.

A versatile molecule is described that performs as a nondestructible read-out optical-storage molecular memory. This molecular memory is composed of two distinct molecules that are chemically bonded to each other to form a single molecule with unique properties. One component is a photochromic fulgimide, and the other is a strongly fluorescing oxazine dye. This composite molecule was specifically designed and synthesized to display, under specific conditions, both the photochromic functions of the first component and the fluorescence properties of the dye. To store information, the polar, closed form of the photochromic component is illuminated with 530-nm light, which converts it to the open, nonpolar form. The information is accessed by excitation at the 650-nm band of the oxazine dye component, causing the dye to fluoresce. However, the dye emits intense fluorescence under a nonpolar environment, which is attained only when the fulgimide component is in its open, nonpolar structure. The ultrafast kinetics, spectroscopy, and mechanism of the photoreaction of this molecule and its photoinduced intermediates have been measured, and fluorescence quantum yields and cross sections were determined.

Coloring Agents↗

Teleophthalmology link between a primary health care centre and a reference hospital.

We have evaluated a teleophthalmology service linking a primary health care centre and an eye clinic at a reference hospital. General practitioners at the primary care centre serving a population of 15,000 and ophthalmologists at the reference hospital participated in this study. Eye fundus digital images were taken from 278 eye fundi of 139 consecutive patients with clinical conditions that could potentially produce fundus alterations. Fundus images were obtained with a non-mydriatic fundus camera (Canon CR6-45M) and were electronically sent reference hospital where ophthalmologist inspected the images and returned the diagnosis. In 18 patients (13%) the images did not have good enough quality to exclude eye fundus lesions. In 24 patients (17%) clear eye fundus alterations were found in at least one eye. In 14 patients (10%) there were image features suggesting retinal alterations that could not be confirmed by image inspection. Media opacity (13 eyes, 5%, seven patients, 5%) was the most common cause of poor image quality. The most difficult assessment was the evaluation of optic nerve head cupping. Retinal oedema was not observable in the digital images. In our experience teleopthalmology services seem to be an effective alternative for eye fundus diagnosis and patient follow-up.

Computer Communication Networks↗

Compressing data volume of left ventricular cineangiograms.

In this paper a method of compressing data volume for left ventricular cineangiograms is proposed. This method enables digital-optical discs to store the cineangiograms with an equivalent recording density to that of HDTV VTR's while preserving the quality of the original image. The data volume of the cineangiograms is compressed by approximating function and storing its coefficients. With this method, each cineangiogram frame is first decomposed into three regions: the inner part, the inner wall, and the background (using a statistical method previously reported by the authors). Each region is then compressed by means of a difference operation and an adaptive approximation with smooth functions. Performance is tested on 20 cases using actual cineangiograms. The specifications were verified for a spatial resolution of 1000 TV lines, a dynamic range of 60 dB, an SNR of 40 dB [pp/rms], volume compression to 7% of the original volume, and 0.19 [second/frame] for decoding on a 1.7 MFLOPS computer.

Algorithms↗