Hydrogen Production from Hydrophobic Ruthenium Dye-Sensitized TiO Photocatalyst Assisted by Vesicle Formation.

Dye-sensitized H evolution photocatalysts have attracted considerable attention as promising systems for the photochemical generation of H from water. In this study, to mimic the reaction field of natural photosynthesis artificially, we synthesized a hydrophobic Ru(II) dye-sensitized Pt-TiO nanoparticle photocatalyst, @Pt-TiO ( = [Ru(dCbpy)(Hdmpbpy)]; dCbpy = 4,4'-dinonyl-2,2'-bipyridine, Hdmpbpy = 4,4'-dimethyl phosphonic acid-2,2'-bipyridine), and integrated it into 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC) lipid bilayer vesicle membranes. The photocatalytic H production activity in 0.

[Construction and Analysis of a Digital Mammography Database: Analysis of Breast Compression Pressures at Four Facilities].

We analyzed the compression pressures in 2772 mammography images of 807 patients acquired by digital mammography equipment at four facilities. The analysis included the average compression pressure at all facilities, difference in compression pressure at each facility, differences between the pressures used by radiological technologists in the same facility, and difference attributed to the breast structure. We also analyzed the effects of the compression pressure on the breast thickness and mean glandular dose (MGD) at each facility.

Indices for the evaluation of glandular dose heterogeneity in full-field digital mammography.

This study aims to evaluate the indices of glandular dose heterogeneity in full-field digital mammography. The distributions of GD in a breast phantom with a skin layer of 4 mm were determined using the Monte Carlo method with simulated x-ray fluence spectra. First, the GD to air kerma (GD/) volume histogram was obtained from the GD distributions, which were indicated by the glandular volume (%) as a function of GD/.

Reduction of tobacco smoke exposure for pregnant passive smokers using feedback of urinary cotinine test results.

Aims: Our objective was to evaluate the level of pregnant women's exposure to tobacco smoke by urinary cotinine testing at prenatal examinations, and to examine the effects of disclosing the results of urinary cotinine tests to pregnant women and their families on their smoking activities.

Methods: A prospective cohort study was conducted, enrolling 420 pregnant women who attended prenatal examinations at five private clinics in Japan. Urinary cotinine testing and a questionnaire survey regarding smoking status were conducted in early, middle, and late pregnancy.

Investigation of optimum anti-scatter grid selection for digital radiography: physical imaging properties and detectability of low-contrast signals.

Our aim in this study was to evaluate the effect of the grid variations on the imaging performance for a computed radiographic system under identical exposure condition. Digital radiographies using a 20-cm Lucite phantom were performed without grid and with grid ratios of 5:1, 8:1, 10:1, 12:1, and 14:1. The scatter fraction, the incident dose to the image receptor, the Wiener spectrum (WS), and the noise-equivalent quanta (NEQ) were measured.

Digital magnification mammography with matched incident exposure: physical imaging properties and detectability of simulated microcalcifications.

Our purpose was to evaluate the usefulness of digital magnification mammography with matched incident exposure by investigating the physical imaging properties and doing an observer performance test. A computed radiography system and a mammographic unit were used in this study. Contact and magnification radiographies of 1.

Automated segmentation method of white matter and gray matter regions with multiple sclerosis lesions in MR images.

Our purpose in this study was to develop an automated method for segmentation of white matter (WM) and gray matter (GM) regions with multiple sclerosis (MS) lesions in magnetic resonance (MR) images. The brain parenchymal (BP) region was derived from a histogram analysis for a T1-weighted image. The WM regions were segmented by addition of MS candidate regions, which were detected by our computer-aided detection system for the MS lesions, and subtraction of a basal ganglia and thalamus template from "tentative" WM regions.

Comparison of detectability of a simple object with low contrast displayed on a high-brightness color LCD and a monochrome LCD.

The goal of this study was to investigate the effect of the different luminance settings of a high-brightness color liquid-crystal display (LCD) on the detectability of a simple grayscale object with low contrast by use of receiver operating characteristic (ROC) analysis. The detectability of a high-brightness color LCD with two maximum-luminance settings (500 and 170 cd/m(2)) was compared with the detectability of a monochrome LCD (500 cd/m(2)). The two LCDs used in this study were calibrated to the grayscale standard display function.

Partial volume estimation and segmentation of brain tissue based on diffusion tensor MRI.

Purpose: Brain tissue segmentation based on diffusion tensor magnetic resonance imaging (DT-MRI) data has been attempted by previous researchers. Due to inherent low spatial resolution of DT-MRI data, conventional methods suffered from partial volume averaging among the different types of tissues, which may result in inaccurate segmentation results. The purpose was to develop a new brain tissue segmentation method for DT-MRI data in which effect of the partial volume averaging is taken into account.

Computer-aided detection of multiple sclerosis lesions in brain magnetic resonance images: False positive reduction scheme consisted of rule-based, level set method, and support vector machine.

The purpose of this study was to develop a computerized method for detection of multiple sclerosis (MS) lesions in brain magnetic resonance (MR) images. We have proposed a new false positive reduction scheme, which consisted of a rule-based method, a level set method, and a support vector machine. We applied the proposed method to 49 slices selected from 6 studies of three MS cases including 168 MS lesions.

[Application of the grayscale standard display function to general purpose liquid-crystal display monitors for clinical use].

Interpretations of medical images have been shifting to soft-copy readings with liquid-crystal display (LCD) monitors. The display function of the medical-grade LCD monitor for soft-copy readings is recommended to calibrate the grayscale standard display function (GSDF) in accordance with the guidelines of Japan and other countries. In this study, the luminance and display function of five models of eight general purpose LCD monitors were measured to gain an understanding of their characteristics.

Computer-aided evaluation method of white matter hyperintensities related to subcortical vascular dementia based on magnetic resonance imaging.

It has been reported that the severity of subcortical vascular dementia (VaD) correlated with an area ratio of white matter hyperintensity (WMH) regions to the brain parenchyma (WMH area ratio). The purpose of this study was to develop a computer-aided evaluation method of WMH regions for diagnosis of subcortical VaD based on magnetic resonance (MR) images. A brain parenchymal region was segmented based on the histogram analysis of a T1-weigthed image.

Effect of ambient light variations on luminance ratio of CRT monitor and image contrast in ultrasonography.

Variation in the luminance ratio of a cathode ray tube(CRT)monitor and the ultrasonographic images at different levels of ambient light(0-150 lux)was investigated to obtain optimum ambient light in the ultrasonography suite. The maximum and minimum luminances of test patterns and ultrasonographic images were measured after three technicians independently optimized the brightness and contrast of the CRT monitor and ultrasonographic images at different levels of ambient light. Furthermore, the luminance ratio was calculated from the maximum luminance divided by the minimum luminance.

Comparison of viewing angle and observer performances in different types of liquid-crystal display monitors.

It is known that the performance of liquid-crystal display (LCD) monitors, such as the luminance and contrast ratio, is dependent on the viewing angle. Our purpose in this study was to compare the angular performance and the effect on observer performance of different types of LCD monitors. The luminance performance and contrast ratio as a function of viewing angle (-60 degrees to 60 degrees) in each direction for two types of LCD monitors, namely, a general-purpose LCD monitor and one especially designed for medical use, were measured in this study.

Computerized method for estimation of the location of a lung tumor on EPID cine images without implanted markers in stereotactic body radiotherapy.

The purpose of this study was to develop a computerized method for estimation of the location of a lung tumor in cine images on an electronic portal imaging device (EPID) without implanted markers during stereotactic body radiotherapy (SBRT). Each tumor region was segmented in the first EPID cine image, i.e.

Need for liquid-crystal display monitors having the capability of rendering higher than 8 bits in display-bit depth.

Our purpose in this study was to examine the potential usefulness of liquid-crystal display (LCD) monitors having the capability of rendering higher than 8 bits in display-bit depth. An LCD monitor having the capability of rendering 8, 10, and 12 bits was used. It was calibrated to the grayscale standard display function with a maximum luminance of 450 cd/m(2) and a minimum of 0.

Performance evaluation of radiologists with artificial neural network for differential diagnosis of intra-axial cerebral tumors on MR images.

Background And Purpose: Previous studies have suggested that use of an artificial neural network (ANN) system is beneficial for radiological diagnosis. Our purposes in this study were to construct an ANN for the differential diagnosis of intra-axial cerebral tumors on MR images and to evaluate the effect of ANN outputs on radiologists' diagnostic performance.

Materials And Methods: We collected MR images of 126 patients with intra-axial cerebral tumors (58 high-grade gliomas, 37 low-grade gliomas, 19 metastatic tumors, and 12 malignant lymphomas).

Automated method for identification of patients with Alzheimer's disease based on three-dimensional MR images.

Rationale And Objectives: An automated method for identification of patients with cerebral atrophy due to Alzheimer's disease (AD) was developed based on three-dimensional (3D) T1-weighted magnetic resonance (MR) images.

Materials And Methods: Our proposed method consisted of determination of atrophic image features and identification of AD patients. The atrophic image features included white matter and gray matter volumes, cerebrospinal fluid (CSF) volume, and cerebral cortical thickness determined based on a level set method.

MR tractography based on directional diffusion function validation in somatotopic organization of the pyramidal tract.

Rationale And Objectives: Conventional tractography based on the "streamline" method only partially visualizes the pyramidal tract because of fiber crossing with other white matter tracts. Recently a new tractography method based on directional diffusion function (DDF) has been proposed. This method was reported to visualize the pyramidal tract to a larger extent than conventional techniques do.

Estimation of white matter connectivity based on a three-dimensional directional diffusion function in diffusion tensor MRI.

Diffusion tensor (DT) magnetic resonance imaging (MRI) provides the directional information of local neuronal fibers, and has been used to estimate the neuroanatomical connectivity in the cerebral white matter. Several methods for white matter tractography have been developed based on DT-MRI. However, it has been difficult to estimate the white matter tract pathways in the fiber crossing and branching region because of the ambiguity of the principal eigenvector and/or low anisotropy due to the partial volume effect.

Usefulness of artificial neural network for differential diagnosis of hepatic masses on CT images.

Rationale And Objective: Our purpose in this study is to apply an artificial neural network (ANN) for differential diagnosis of certain hepatic masses on computed tomographic (CT) images and evaluate the effect of ANN output on radiologist diagnostic performance.

Materials And Methods: We collected 120 cases of hepatic disease. We used a single three-layer feed-forward ANN with a back-propagation algorithm.