This paper presents an extension for T1-weighted imaging of the ultra-fast MR imaging method with single-shot and time-unvarying gradient fields. A complete 2-D or 3-D Tr-weighted image can be obtained from two MR images with different inversion acquired by using time-unvarying gradient fields rather than the multiple excitations or the switching gradient fields as used in conventional methods. The principle, the pulse sequence, the strategy of selecting inversion period for producing an inversion recovery of magnetization, the data acquisition procedure, and the reconstruction algorithm are described. Finally, the simulation implemented is introduced. The method has the desirable features of the single-shot technique with time-unvarying gradient fields, including the potential for rapid acquisition, the simplicity of realization, and the elimination of probably harmful influences on patients due to the multiple excitations and the rapidly alternating gradient fields.
To realize a single display system for all kinds of TV image information with different scanning-lines and indicating-channels, a new single-scanning technology with a scan conversion method has been studied by response analysis and by experimental evaluation of picture quality. This study confirmed that a minimum deterioration of a vertical response and no degradation of the motion of an image can be obtained and that the aliasing and flickering effects caused by the use of a conventional interlaced scanning can be eliminated. These advantages are due to a newly developed scan conversion method which employs a double field-rate and wobbling interlaced scanning within four fields. New multimedia such as the HD-TV, digital TV, and 3D-TV can be displayed in the single display system. Furthermore, in the new platform using this technology, it is easy to interface with the HD and 3D package media and image-sensing media.
A new figure identification task for analyzing the relation between information processing and a spontaneous blink is proposed. A characteristic of our visual tasks different from conventional discrete trial tasks is to adopt a time-varying image presentation method. The following two blink-occurrence factors can be analyzed independently by using this method. One of the factors is the factor which relates to the termination of information processing, the other is the factor which relates to discontinuous physical change associated with the onset or offset of a stimulus. In this paper, the psychological experiment was designed using the identification task of Katakana represented in contour. As the result of the experiment, next findings were obtained. First, when the figure is continuously presented during a trial, a blink has the tendency which occur delaying than immediately after the completion of the identification. Second, a blink tends to occur at the onset of the figure which does not include useful information for the identification.