In this study, the transient response of reflectance against pulsed voltage application was measured to analyze the moving mechanism of TiO2 particles in the wax-based electrophoretic rewritable media. By understanding the TiO2 particles motion in the media, it would be an advantage to develop the electrophoretic display technology which is expected to has excellent preservation property. The transient response of the reflectance is affected by the media layer thickness and applied voltage between electrodes. Thus experiments were carried out to understand the such dependence. It was observed that, there is a difference in time responses for transition of colors in between black and white. This is assumed due to the TiO2 particles movement between the electrodes. It is obtained that the TiO2 particle moves approximately proportional to the applied voltage and TiO2 particle mobility is 2.5-5.4×10-11m2/vs. This value is very useful to estimate the response of electrophoretic display.
A theoretical analysis of the two-component magnetic brush development considering both the conductivity of the magnetic brush and the limitation of available toners proceeded. This analysis is based on the model considering the conductivity presented by Folkins. The supposition that the conductivity of the magnetic brush is in proportion to the amount of available toners was added to his model. And the analytical result was obtained. This report shows the result of with-mode development as the first result. The developed toner mass versus the basic development parameters was calculated and the result showed proper values quantitatively. This analysis was applied to a prediction of process speed dependence of development.
In this paper, we review the latest trend of diagnostic imaging modalities, especially X-ray CT, positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). Although only less than 40 years have passed since X-ray CT was invented by Dr. Hounsfield in 1972, X-ray CT has largely advanced in the meanwhile. Helical scan was made possible by the adoption of a slip ring, and then the appearance of multi-detector-row CT scanners has brought the rapid progress of high-speed and high-resolution scans. Recently, dual-energy CT and virtual monochromatic images can be obtained, by which the quantitative accuracy of CT values can be improved, and the possibility of new molecular imaging by use of CT is expected. Regarding the diagnostic imaging modalities for nuclear medicine, we review the recent development of integrated CT/PET and CT/SPECT scanners which allow the fusion of functional and anatomic information. We also review the semiconductor PET and SPECT scanners which allow short data acquisition. In addition, we review newly-developed integrated PET/MR scanners which are expected to integrate the functional images of PET and the functional and/or anatomic images of MRI. These integrated modalities will provide more useful and valuable diagnostic images than either modality can offer alone, leading to the further development of integrated diagnostic imaging. Finally, as topics of the latest trend of MRI, we will focus on the techniques of non-contrast perfusion and angiography and the tissue elasticity imaging (elastography) using MRI.
Three-dimensional motion picture of thoracoabdominal organ due to respiration offers potential application such as us use in diagnosis of those organs, radiotherapy and/or planning, improvement of PET or SPECT image quality. We have developed a method for reconstructing a four-dimensional magnetic resonance image (4D-MRI) of respiratory organ motion from time sequential images of two-dimensional (2D) MR. The developed method properly synthesizes a set of 2D MRI acquired at different slice position using a navigator slice orthogonal to those data slices. The method is introduced and a few examples of 4D-MR images are demonstrated. A prospective method for shortening the acquisition time is also shortly described. As an application of 4D-MRI, diaphragm is extracted from the 4D-MRI and its motion along to body axis is visualized.
The recent advancement of medical imaging technology enables us to obtain detailed and accurate information on morphology and functions in vivo. It is considered to be possible to predict the progress of a disease or the post-operative conditions prior to the surgery by combining the medical images and simulation techniques in the future. The paper presents an emerging method, patient-specific modeling and simulation, and its applications for cardiovascular diseases such as atherosclerosis and cerebral aneurysm. The vascular geometry is constructed from the medical images such as CT and MRI images of particular patients and the simulations are conducted to investigate the hemodynamics in the cerebral circulation and the cerebral aneurysm. The paper also provides the current research situation on the patient-specific modeling and simulation as well as its perspectives.
This paper describes on general features of Optical Coherence Tomography (OCT), its coherence property, Time Domain OCT, Fourier Domain OCT (Spectral Domain OCT and Swept Source OCT), and axial resolution. Especially, SD-OCT and SS-OCT are outlined comparing their common points and differences using schematics. OCT has higher axial resolution of several micron meter rather than other tomographic imaging systems. And also OCT is non-invasive because of using slight near-infrared light. Recently, OCT is widely used as an important and necessary clinical instrument for ophthalmology diagnostics, since OCT can detect early edema invisible from ocular fundus and measure retinal thickness.
X-ray flat panel detector (FPD) is key device allowing X-ray diagnostic systems to support more sophisticated medical care. FPD is solid-state device which provides high quality diagnosis image through the conversion of X-ray images of the human body into digital signals. Features of the FPD are that high quality image can be outputted in real time and shape is compact. These features enable improved diagnostic capabilities, and reduce the burden on the patient. High X-ray detective quantum efficiency (DQE) of FPD is required in order to reduce radiation dose, and high image quality is required in order to detect of small diseases. A fine cesium iodide (CsI) scintillator crystal formation is applied for achieving these performance requirements. In this paper, mainly the techniques of the FPD which made by Toshiba Electron Tubes & Devices Co., Ltd. will be described.