[F]-FDG uptake in brain slices prepared from an aged mouse model of Alzheimer's disease using a dynamic autoradiography technique.

Objective: 2-[F]fluoro-2-deoxy-D-glucose positron emission tomography ([F]-FDG-PET) is a imaging modality that has been used to measure of glucose metabolism in the brain in Alzheimer's disease (AD). Clinically, decreased glucose uptake has been reported in the brain of AD, although the precise underlying mechanisms have not yet been elucidated. To elucidate the mechanisms of decreased [F]-FDG uptake in the AD by PET, [F]-FDG uptake in the brain of aged model mouse of AD was investigated using a dynamic autoradiography technique "bioradiography".

Dietary Exposure to Flame Retardant Tris (2-Butoxyethyl) Phosphate Altered Neurobehavior and Neuroinflammatory Responses in a Mouse Model of Allergic Asthma.

Tris (2-butoxyethyl) phosphate (TBEP) is an organophosphate flame retardant and used as a plasticizer in various household products such as plastics, floor polish, varnish, textiles, furniture, and electronic equipment. However, little is known about the effects of TBEP on the brain and behavior. We aimed to examine the effects of dietary exposure of TBEP on memory functions, their-related genes, and inflammatory molecular markers in the brain of allergic asthmatic mouse models.

Advanced X-ray imaging at beamline 07 of the SAGA Light Source.

The SAGA Light Source provides X-ray imaging resources based on high-intensity synchrotron radiation (SR) emitted from the superconducting wiggler at beamline 07 (BL07). By combining quasi-monochromatic SR obtained by the newly installed water-cooled metal filter and monochromatic SR selected by a Ge double-crystal monochromator (DCM) with high-resolution lens-coupled X-ray imagers, fast and low-dose micro-computed tomography (CT), fast phase-contrast CT using grating-based X-ray interferometry, and 2D micro-X-ray absorption fine structure analysis can be performed. In addition, by combining monochromatic SR obtained by a Si DCM with large-area fiber-coupled X-ray imagers, high-sensitivity phase-contrast CT using crystal-based X-ray interferometry can be performed.

Fast diffraction-enhanced imaging using continuous sample rotation and analyzer crystal scanning.

Diffraction-enhanced imaging (DEI) has high sensitivity and a wide dynamic range of density and thus can be used for fine imaging of biological and organic samples that include large differences in density. A fast DEI method composed of continuous fast sample rotations and slow analyzer crystal scanning was developed to shorten the measurement period. Fine sectional images of a biological sample were successfully obtained within a half measurement period of the conventional step-scanning method while keeping the same exposure time.

Biochemical Characterization of Ferulic Acid and Caffeic Acid Which Effectively Inhibit Melanin Synthesis via Different Mechanisms in B16 Melanoma Cells.

In this study, we examined the inhibitory effects of ferulic acid and caffeic acid on melanin production using a murine B16 melanoma cell line. The mechanisms by which the two acids inhibit melanin production were investigated by evaluating their effects on the activity of tyrosinase, which is involved is the first step of melanin biosynthesis. Ferulic acid showed no toxicity against the melanoma cells at any dose, whereas caffeic acid exerted cellular toxicity at concentrations higher than 0.

Dual-energy fluorescent x-ray computed tomography system with a pinhole design: Use of K-edge discontinuity for scatter correction.

We propose a pinhole-based fluorescent x-ray computed tomography (p-FXCT) system with a 2-D detector and volumetric beam that can suppress the quality deterioration caused by scatter components. In the corresponding p-FXCT technique, projections are acquired at individual incident energies just above and below the K-edge of the imaged trace element; then, reconstruction is performed based on the two sets of projections using a maximum likelihood expectation maximization algorithm that incorporates the scatter components. We constructed a p-FXCT imaging system and performed a preliminary experiment using a physical phantom and an I imaging agent.

Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography.

Phase-contrast X-ray imaging using a crystal X-ray interferometer can depict the fine structures of biological objects without the use of a contrast agent. To obtain higher image contrast, fixation techniques have been examined with 100% ethanol and the commonly used 10% formalin, since ethanol causes increased density differences against background due to its physical properties and greater dehydration of soft tissue. Histological comparison was also performed.

Imaging renal structures by X-ray phase-contrast microtomography.

X-ray crystal interferometer-based X-ray phase-contrast microtomography (phase-contrast microtomography) is able to image microstructures within soft tissue without the use of a contrast agent. Here we determined the feasibility of using this technique in the non-destructive inspection of formalin-fixed kidney tissue from certain hamsters that spontaneously develop mesangial thickening with focal and segmental glomerulosclerosis, and from age-matched Syrian hamsters. We used a triple Laue-case X-ray interferometer with a 40 microm-thick analyzer, a sample cell, and an X-ray charge-coupled-device camera with a 4.

Sheet-beam geometry for in vivo fluorescent x-ray computed tomography: proof-of-concept experiment in molecular imaging.

We propose a fluorescent x-ray computed tomography method using an array of detectors with an incident sheet beam, aimed at providing molecular imaging with high sensitivity and good spatial resolution. In this study, we prove the feasibility of this concept and investigate its imaging properties, including spatial and contrast resolutions and quantitativeness, by imaging an acrylic phantom and a normal mouse brain using a preliminary imaging system with monochromatic synchrotron x rays.

99mTc-N-DBODC5: a novel myocardial perfusion imaging agent for diagnosis of coronary artery disease, a review.

In myocardial SPECT imaging with the popularly used 99mTc-sestamibi and 99mTc-tetrofosmin, intense liver uptake leads to a paradoxical decrease of counts in the absence of perfusion abnormalities, making it difficult to assess myocardial perfusion, particularly in the inferior or inferoapical left ventricular wall. 99mTc-N-DBODC5, which is a new lipophilic, mono-cationic nitride myocardial perfusion imaging agent, exhibits high myocardial uptake and excellent bio-distribution kinetics with rapid liver clearance in rats and dogs. 99mTc-N-DBODC5 myocardial imaging during vasodilator stress can determine the severity of stenosis, though underestimates occur with mild coronary stenosis compared to 201Tl, in a similar way to what occurs with 99mTc-sestamibi and 99mTc-tetrofosmin.

Quantitative evaluation of myocardial function by a volume-normalized map generated from relative blood flow.

Our study aimed to quantitatively evaluate blood flow in the left ventricle (LV) of apical hypertrophic cardiomyopathy (APH) by combining wall thickness obtained from cardiac magnetic resonance imaging (MRI) and myocardial perfusion from single-photon emission computed tomography (SPECT). In this study, we considered paired MRI and myocardial perfusion SPECT from ten patients with APH and ten normals. Myocardial walls were detected using a level set method, and blood flow per unit myocardial volume was calculated using 3D surface-based registration between the MRI and SPECT images.

Interferometer-based phase-contrast X-ray computed tomography of colon cancer specimens: comparative study with 4.74-T magnetic resonance imaging and optical microscopy.

Objective: Phase-contrast X-ray computed tomography (PCCT) with an interferometer can reveal the inner soft tissue structures of biological objects without contrast agent, and the image quality is thought to resemble that of magnetic resonance imaging (MRI). Comparative study among PCCT, MRI, and optical microscopy was undertaken.

Methods: Three formalin-fixed colon cancer specimens from nude mice were imaged both by PCCT with a reconstructed volumetric resolution of (0.

Preliminary quantitative analysis of myocardial fatty acid metabolism from fluorescent X-ray computed tomography imaging.

Fluorescent X-ray computed tomography (FXCT) using synchrotron radiation reveals the cross-sectional distribution of specific elements in biomedical objects. The aim of this study was to investigate the feasibility of FXCT imaging to assess the myocardial metabolic state quantitatively. Hearts labelled with non-radioactive iodine myocardial fatty acid agent 15-p-(iodophenyl)-3-methylpentadecanoic acid (BMIPP) from cardiomyopathic and normal hamsters were imaged.

High-energy phase-contrast X-ray imaging using a two-crystal X-ray interferometer.

To broaden the scope of phase-contrast X-ray imaging in biomedical applications, the energy of X-rays in a large-area imaging system using a two-crystal X-ray interferometer has been increased from 17.7 keV to 35 keV. The use of higher-energy X-rays makes it possible to observe larger samples having greater variation in density within shorter measurement periods, at higher spatial resolution, and at lower X-ray doses.

Coherence-contrast x-ray imaging based on x-ray interferometry.

Coherence-contrast x-ray imaging--which detects changes in the degree of coherence caused by the placement of a sample in an x-ray interferometer--was developed for biomedical applications. Because the technique's sensitivity depends on the density gradient in the sample, it is particularly suitable for observing biomedical samples with large density differences, such as samples that include both biological soft tissue and bone. A measurement principle and method of this technique are described, and a fine coherence-contrast image of a mouse leg is given as an example result.

Mismatch between gallium-67 uptake and CT findings in a case of pulmonary alveolar proteinosis.

Gallium-67 citrate (67Ga) scintigraphy has been used as an indicator of activity of diffuse interstitial lung diseases. However, little has been mentioned in pulmonary alveolar proteinosis (PAP). Here we present a 53-year-old man with PAP showing patchy 67Ga uptake by single photon emission computed tomography (SPECT).

Abnormal retention of 99mTc-TF in a hamster model of cardiomyopathy analyzed by 99mTc-TF and 125I-BMIPP autoradiography.

Objective: Enhanced washout of 99mTc-tetrofosmin (TF) has been reported in patients with hypertrophic cardiomyopathy (HCM). Here, using quantitative dual-autoradiography, the relationship between TF retention abnormality and metabolism depicted by 125I-BMIPP uptake was investigated quantitatively in a hamster model of cardiomyopathy.

Methods And Results: Early and delayed TF images were obtained at 5 min (7 cardiomyopathic and 5 normal hamsters) and 60 min (8 cardiomyopathic and 5 normal hamsters) after injection, respectively.

[Phase-contrast x-ray imaging with x-ray interferometer for medical applications].

Phase-contrast x-ray imaging with x-ray interferometer can depict the minute difference within the biological object, and its sensitivity is about 1000 times higher than that of absorption-contrast method. For biomedical use of this technique, a large monolithic x-ray interferometer and 2 crystal interferometer having a field of view with 25 mm x 25 mm is being developed. Phase-contrast x-ray CT could reveal detail structures within tumor and surrounded tissue, and the vessel imaging of rat liver is also possible using physiological saline at 17.

Enhanced washout of 99mTc-tetrofosmin in hypertrophic cardiomyopathy: quantitative comparisons with regional 123I-BMIPP uptake and wall thickness determined by MRI.

The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 beta-methyl- p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment.

Vessel imaging by interferometric phase-contrast X-ray technique.

Background: Phase-contrast x-ray imaging using an x-ray interferometer has great potential to reveal the structures inside soft tissues, because the sensitivity of this method to hydrogen, carbon, nitrogen, and oxygen is approximately 1000 times higher than that of the absorption-contrast x-ray method. Imaging of vessels is very important to understand the vascular distribution of organs and tumors, so the possibility of selective angiography based on phase contrast is examined with a physiological material composed of low-atomic-number elements.

Methods And Results: Phase-contrast x-ray imaging was performed with a synchrotron x-ray source.