Japanese Journal of Radiological Technology

It has been noted that the downtime of medical informatics systems is often long. Many systems encounter downtimes of hours or even days, which can have a critical effect on daily operations. Such systems remain especially weak in the areas of database and medical imaging data. The scheme design shows the three-layer architecture of the system: application, database, and storage layers. The application layer uses the DICOM protocol (Digital Imaging and Communication in Medicine) and HTTP (Hyper Text Transport Protocol) with AJAX (Asynchronous JavaScript+XML). The database is designed to decentralize in parallel using cluster technology. Consequently, restoration of the database can be done not only with ease but also with improved retrieval speed. In the storage layer, a network RAID (Redundant Array of Independent Disks) system, it is possible to construct exabyte-scale parallel file systems that exploit storage spread. Development and evaluation of the test-bed has been successful in medical information data backup and recovery in a network environment. This paper presents a schematic design of the new medical informatics system that can be accommodated from a recovery and the dynamic Web application for medical imaging distribution using AJAX.

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The combination of angiography and CT angiography (CTA) is increasingly being used for the diagnosis and treatment of hepatic cancer. Recently, a CT system with sliding gantry was developed to optimize patient safety and to shorten transfer time between the angiography and CTA tables. As the CT gantry itself undergoes considerable movement in sliding over the patient table, it was considered necessary to evaluate this system regarding the precision of movement and any possible effect on image quality. Therefore, in this preliminary study, we compared image quality between the sliding gantry CT (SGCT) system and the sliding table CT (STCT) system. Comparative analysis revealed that there was no significant difference in image noise, low contrast resolution, modulation transfer function (MTF) , or precision in gantry or table movement. It was also noted that although the effective slice thickness for the SGCT system was 1-4% thinner than the STCT system it had no influence on image quality. It was thus concluded that the sliding movement of the gantry does not influence the quality of images obtained with this CT system.

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Echo planar imaging (EPI) is highly sensitive to static magnetic field inhomogeneities. The degree of local image compression and stretching is a function of the static field gradient in the phase-encoding direction. This is caused by the accumulation of a phase shift. Any static field shift will lead to a position shift in the image, and it is the regions with large static fields that are the most difficult to correct. We reduce image distortion by SENSE with an array coil. However, we often use a surface coil because we cannot use an array coil in clinical studies. In this case, image distortion becomes greater, and reduction of distortion is very important. For the purpose of this study, we examined the relation between imaging parameters and image distortion. Image distortion of EPI is unrelated to the following parameters: number of phase encodings, half scan, echo time, and diffusion b-value. However, the following parameters influenced image distortion: FOV, number of frequency encodings, rectangle FOV, and multi-shot imaging. Image distortion of EPI is decided by the area of the phase-encoding gradient and the interval of readout gradients. We hope that many institutions will find these data useful.

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Background and Objectives: In the "Grand Design for Computerization of the Medical Field" of December, 2001, the Ministry of Health, Labour and Welfare set a numerical target for the adoption of electronic medical charts nationwide in at least 60% hospitals with 400 or more beds. Therefore, the introduction and operation of an order-entry system, which is necessary for establishing electronic medical charts, became essential for each of these medical facilities. We surveyed the current state of order-entry systems for nuclear medicine, which are considered difficult to introduce owing to the particulars of their operation, and herewith report the results. Methods: Questionnaires with a request for cooperation were sent by mail to 119 facilities nationwide that are engaged in nuclear medicine. The questionnaire surveyed 21 items, including operational status and restrictions of the order-entry system. Results: The absolutely essential restriction settings for the introduction and operation of an order-entry system were not being used, and the scheduling of tests was being conducted on the basis of human judgment. Conclusion: The development of an order-entry system that includes standardization of basic specifications (restrictions) according to the content and work are necessary for nuclear scans, for which the introduction and operation of an order-entry system can cause concern owing to the particulars of operation in the field of radiation.

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