Tokuo Umeda

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The effectiveness of a hospital information system (HIS) and a radiological information system (RIS) was evaluated to optimize preparation for the planned full clinical operation of a picture archiving and communication system (PACS), which is now linked experimentally to the HIS and the RIS. One thousand IC (integrated circuit) cards were used for time(More)
Currently, a large number of endovascular interventions are performed for treatment of intracranial aneurysms. For these treatments, correct positioning of microcatheter tips, microguide wire tips, or coils is essential. Techniques to detect such devices may facilitate endovascular interventions. In this paper, we describe an algorithm for tracking of(More)
We evaluated the X-ray digital linear tomosynthesis reconstruction processing method for metal artifact reduction. A volumetric X-ray digital linear tomosynthesis instrument was used to image a hip prosthesis. Artifacts caused by high-attenuation features in hip prostheses were observed in digital linear tomosynthesis reconstruction due to the few(More)
To explore the possibility of decreasing the radiation dose during digital tomosynthesis (DT) for arthroplasty, we compared the image qualities of several reconstruction algorithms, such as filtered back projection (FBP) and two iterative reconstruction (IR), methods maximum likelihood expectation maximization (MLEM) and the simultaneous iterative(More)
PURPOSE Quantum noise impairs image quality in chest digital tomosynthesis (DT). A wavelet denoising processing algorithm for selectively removing quantum noise was developed and tested. METHODS A wavelet denoising technique was implemented on a DT system and experimentally evaluated using chest phantom measurements including spatial resolution.(More)
We compared three techniques for enhancement of microcatheter tips in fluoroscopic images: conventional subtraction technique (CST); averaged image subtraction technique (AIST), which we have developed; and double average filtering (DAF) technique, which uses nonlinear background estimates. A pulsed fluoroscopic image sequence was obtained as a(More)
It is not easy to connect a web-based server with an existing DICOM server, and using a web-based server on the INTERNET has risks. In this study, we designed and developed the secure DICOM-Network Attached Server (DICOM-NAS) through which the DICOM server in a hospital-Local Area Network (LAN) was connected to the INTERNET. After receiving a Client's image(More)
PURPOSE This work was aimed at quantification of lactate concentration using proton MR spectroscopy (MRS). We carried out a basic study to clarify the characteristics of signal change and T2 relaxation time of lactate that occur by J coupling in point resolved spectroscopy (PRESS) sequence. MATERIALS AND METHODS Proton MRS was done for a water phantom(More)