Tokuo Umeda

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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)
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)
RATIONALE AND OBJECTIVES To compare the effectiveness of chest dual-energy subtraction digital tomosynthesis (DES-DT) imaging with that of DES radiography for detecting simulated pulmonary nodules with and without calcifications. MATERIALS AND METHODS A DES-DT and DES radiography system (SonialVision Safire II, Shimadzu Co, Kyoto, Japan) with pulsed(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)
OBJECTIVE A newly developed compression and transmission system of ultrasound image sequence for telemedicine is proposed for transmitting ultrasonic image sequence in real time via IP-connected computers for telemedicine. MATERIALS AND METHODS In the compression method, the characteristics of ultrasound images were taken into account. Only sound data(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)
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)
Organ movements that occur naturally as a result of vital functions such as respiration and heartbeat cause deterioration of image quality in nuclear medicine imaging. Among these movements, respiration has a large effect, but there has been no practical method of correcting for this. In the present study, we examined a method of correction that uses(More)