Search

To evaluate 1.5 T magnetic resonance imaging (MRI) brain images with denoising procedures using deep learning-based reconstruction (dDLR) relative to the original 1.5 and 3 T images.Eleven volunteers underwent MRI at 3 and 1.5 T. Two-dimensional fast spin-echo T2-weighted imaging (T2WI), fluid-attenuated inversion recovery (FLAIR) imaging and diffusion-weighted imaging (DWI) sequences were performed. The dDLR method was applied to the 1.5 T data (dDLR-1.5 T), then the image quality of the dDLR-1.5 T data relative to the original 1.5 T and 3 T data was qualitatively and quantitatively assessed based on the structure similarity (SSIM) index; the signal-to-noise ratios (SNRs) of the grey matter (GM) and white matter (WM); and the contrast-to-noise ratios (CNRs) between the GM and WM (CNRgm-wm) and between the striatum (ST) and WM (CNRst-wm).The perceived image quality, and SNRs and CNRs were significantly higher for the dDLR-1.5 T images versus the 1.5 T images for all sequences and almost comparable or even superior to those of the 3 T images. For DWI, the SNRs and CNRst-wm were significantly higher for the dDLR-1.5 T images versus the 3 T images.The dDLR technique improved the image quality of 1.5 T brain MRI images. With respect to qualitative and quantitative measurements, the denoised 1.5 T brain images were almost equivalent or even superior to the 3 T brain images.

Summary Objective Previous work has shown that high body mass index (BMI) is associated with low grey matter volume. However, evidence on the relationship between waist circumference (WC) and brain volume is relatively scarce. Moreover, the influence of mild obesity (as indexed by WC and BMI) on brain volume remains unclear. This study explored the relationships between WC and BMI and grey matter volume in a large sample of Japanese adults. Methods The participants were 792 community‐dwelling adults (523 men and 269 women). Brain magnetic resonance images were collected, and the correlation between WC or BMI and global grey matter volume were analysed. The relationships between WC or BMI and regional grey matter volume were also investigated using voxel‐based morphometry. Results Global grey matter volume was not correlated with WC or BMI. Voxel‐based morphometry analysis revealed significant negative correlations between both WC and BMI and regional grey matter volume. The areas correlated with each index were more widespread in men than in women. In women, the total area of the regions significantly correlated with WC was slightly greater than that of the regions significantly correlated with BMI. Conclusions Results show that both WC and BMI were inversely related to regional grey matter volume, even in Japanese adults with somewhat mild obesity. Especially in populations with less obesity, such as the female participants in current study, WC may be more sensitive than BMI as a marker of grey matter volume differences associated with obesity.

We propose a method of non-invasively evaluating the permeability of cell membranes in normal rat brain using diffusion magnetic resonance imaging (MRI). Diffusion MRI signals reflect the intra- and extracellular diffusion coefficients of water molecules in permeable biological tissues and cell membranes. The signals were acquired using a 4.7 T MRI system and applying a motion-probing gradient (MPG) in six directions. Numerical simulations using the finite-difference method were conducted for various combinations of intracellular diffusion coefficients and cell-membrane permeabilities. We defined the evaluative function as the difference between the signals from numerical simulations and experimentally obtained signals. We found that the minimum value for the evaluative function enabled us to estimate the intracellular diffusion coefficient and membrane permeability of the rat brain, which were corresponded to (1.3±0.1) × 10-3 mm2/sec and 66±24 μm/sec. Our method was useful for non-invasively estimating the cell-membrane permeability of biological tissues, and can easily be applied to human tissues and other samples.

The magnetic alloy (MA)-loaded RF cavity has been studied for an RF stacking system of the accumulator cooler ring (ACR). RF characteristics of several high-permeability MA cores were measured in the frequency range between 1 and 50 MHz. The effects of the cut-core configuration, cutting the core and leaving air gaps between two circular halves, were also investigated. The results show that the shunt impedance remains high and the appropriate inductance and Q-value can be obtained by increasing the gap width of the cut core in the frequency region of the ACR cavity.

To evaluate the diagnostic value of a halo on computed tomography (CT) in the diagnosis of invasive pulmonary aspergillosis (IPA), we retrospectively reviewed chest CT scans and autopsy reports for patients who had been admitted to our hospitals for the treatment of hematological malignancy. Pulmonary complications were suspected in all patients and chest CT scans were taken within a month of death. We examined the association between autopsy and CT findings in 48 patients who were diagnosed as IPA (n = 17), candidosis (n = 4), zygomycosis (n = 2), infiltration of hematological malignancy (n = 12), bacterial pneumonia (n = 6), cytomegalovirus pneumonia (n = 2), pulmonary hemorrhage (n = 2), or pulmonary congestion (n = 1). Patients with IPA showed a variety of CT findings, including halo (n = 13), nodules (n = 14), granular shadows (n = 3), masses (n = 6), consolidations (n = 9), wedge-shaped consolidations (n = 1), and cavitation (n = 2). In contrast, 0, 11 and two of the 31 patients without IPA showed halo, nodules and masses, respectively. These signs were more frequently observed in IPA patients than in non-IPA patients. The CT halo, especially, seemed to be specific for IPA in hospitalized neutropenic patients with hematological malignancies who developed antibiotic-resistant fever. For CT findings other than these three signs, there were no significant differences between IPA- and non-IPA patients.

Soil compaction is the alteration of physical properties of the soil and has significant effect on crop production. With the introduction of larger and heavier agriculture machinery it is now a problem throughout the world. Significant knowledge is still required to study and develop a model to predict soil compaction. Numerous theoretical models are now available but these are far from being able to resolve practical problems. A combination of experimental study and theoretical calculations may provide a solution and lead to the development of an effective predictive model. In this study, experiments involving bead-grid are used to measure soil deformation under an axial compressive load. Measurement of horizontal and lateral deformations was performed using precision potentiometers and the data transferred to a computer for the plotting of deformation contours and soil deformation analysis. The results show that the bead-grid method provides an effective and accurate means for measuring soil deformation.

✓ The authors describe acute deterioration in facial and acoustic neuropathies following radiosurgery for acoustic neuromas. In May 1995, a 26-year-old man, who had no evidence of neurofibromatosis Type 2, was treated with gamma knife radiosurgery (GKS; maximum dose 20 Gy and margin dose 14 Gy) for a right-sided intracanalicular acoustic tumor. Two days after the treatment, he developed headache, vomiting, right-sided facial weakness, tinnitus, and right hearing loss. There was a deterioration of facial nerve function and hearing function from pretreatment values. The facial function worsened from House—Brackmann Grade 1 to 3. Hearing deteriorated from Grade 1 to 5. Magnetic resonance (MR) images, obtained at the same time revealed an obvious decrease in contrast enhancement of the tumor without any change in tumor size or peritumoral edema. Facial nerve function improved gradually and increased to House—Brackmann Grade 2 by 8 months post-GKS. The tumor has been unchanged in size for 5 years, and facial nerve function has also been maintained at Grade 2 with unchanged deafness. This is the first detailed report of immediate facial neuropathy after GKS for acoustic neuroma and MR imaging revealing early possibly toxic changes. Potential explanations for this phenomenon are presented.

High-intensity, high-quality beams originating from the electron-cooling method will be utilized for medical and other application at HIMAC. As a first step, an electron cooler with an adiabatic expansion factor of 10 has been designed and is under construction at HIMAC. So far, field measurements of the cooler have been completed. In this paper, the present status of the electron cooler under construction is described, and plans of medical and other application by using the electron-cooling method at HIMAC are presented.

An ablation plasma generated by intense, pulsed ion beam was used for thin-film deposition of commercially interesting material (Ba/sub x/,Sr/sub 1-x/)TiO/sub 3/ (0

In order to study the frequency of secondary infections of AIDS autopsy cases in Japan, especially the frequency of Mycobacterium aviumintracellulare complex (MAC) infection, retrospective autopsy study was conducted between 1986 and 1997 at the affiliated hospital of Institute of Medical Sciences, University of Tokyo. Secondary infections of various organs from 43 AIDS autopsy cases were examined using histopathology, genetic diagnosis of tuberculosis, Ziehl-Neelsen stain for acid-fast bacilli and immunohistochemistry. Nontuberculous mycobacterial infection (Mycobacterium avium) was observed in 17 cases (40%) out of 43 using polymerase chain reaction (PCR), but M. tuberculosis infection was not observed. Ziehl-Neelsen staining showed a positive reaction in lung and spleen tissues of 7 AIDS autopsy cases. Immunohistochemistry using anti-BCG antibody revealed positivity in 7 AIDS autopsy cases. CD4 counts of 17 AIDS patients with mycobacterial infection were less than 18.7/microl. Other opportunistic infections were also examined by histopathology. Secondary infections were present in every case, and these included cytomegalovirus infection (32 cases), Pneumocystis carinii (15 cases), Candida (16 cases), Aspergillus (12 cases), Cryptococcus (6 cases), Toxoplasma (6 cases), methicillin-resistant Staphylococcus aureus (3 cases), herpes virus (1 case) and Entamoeba histolytica (1 case). Malignant lymphoma was recognized in 14 cases and Kaposi's sarcoma in 6. This is the systemic report on secondary infections of AIDS autopsy cases in Japan. In diagnosis of mycobacterial infections, PCR was more useful than staining for acid-fast bacilli and immunohistochemistry. Secondary infections (especially mycobacterial infection) were closely associated with the low CD4 count.

The anatomy of the gastric veins and gastric varices is complex, and is difficult to understand even with digital subtraction angiography. In balloon-occluded retrograde transvenous obliteration (BRTO) of gastric varices, accurate assessment of the vascular anatomy is essential for successful treatment. Here, we report the case of a patient with gastric varices who was successfully treated with BRTO using three-dimensional rotational angiography.

The rice blast fungus, Pyricularia grisea, was isolated from all diseased spikelets within a single panicle collected from a paddy fields in Hoya and a field in Terada in the Shonai district of Yamagata Prefecture, and the genotypes were identified using pot2 rep-PCR fingerprinting. Among the 300 monoconidial blast isolates were obtained from each panicle. Four and six genotypes were detected at Hoya and Terada, respectively. The isolates with the predominant genotypes were widely distributed in both panicles.

The effects of forward speed and optional plow attachments on draft and soil manipulation caused by a moldboard plow in Eniwa volcanic ash soils were studied using an open air soil bin. Soil moisture content was maintained at 36% (dry basis) while forward speeds ranged from 1.0 to 4.0 m/s. The effects of optional coverboard and plow extension attachments were studied. The results indicated that draft increased with increases in travel speed but that the rate of change differed with speed levels. Within the practical and economical tillage operations speed range, however, the assumption of a linearly increasing speed-draft relationship seemed to be quite valid. Increases in speed and the use of a coverboard and a plow extension resulted in more soil pulverization.

The purpose of this retrospective study was to assess the efficacy of salvage radiation therapy (RT) or chemoradiation therapy (CRT) for locoregional recurrence (LR) of esophageal cancer after curative surgery. Forty-two patients who received salvage RT or CRT for LR of esophageal cancer after curative surgery between November 2000 and May 2012 were reviewed. The intended RT regimen was 60 Gy in 30 fractions combined with concurrent platinum-based chemotherapy. Median follow-up periods were 17.9 months for all evaluable patients and 28.2 months for patients still alive (19 patients) at analysis time. The 1-, 2-, and 3-year survival rates were 81.2 ± 6.4%, 51.3 ± 8.6%, and 41.1 ± 8.7%, respectively, with a median survival time of 24.3 ± 4.1 months. Out of 41 evaluable patients, 16 patients (39%) were alive beyond 2 years from salvage therapy. However, univariate analyses for overall survival showed no significant prognostic factor. Grade 3 or higher leukocytopenia was observed in 46% of the patients. Salvage RT or CRT for LR after surgery for esophageal cancer was safe and effective. These therapies may offer long-term survival to some patients. RT or CRT should be considered for LR.

Retrospective analysis of findings at double-phase helical computed tomography (CT) during arterial portography was performed in 42 hepatocellular carcinomas (HCCs) in 31 patients. Phase 1 scanning started 30-35 seconds after the beginning of injection of contrast material; phase 2 scanning started 10-18 seconds after the end of phase 1. The overall detection rate for HCCs was 83% (35 of 42) in phase 1, 81% (34 of 42) in phase 2, and 90% (38 of 42) for combined phase 1 and 2 findings.

To determine the computed tomographic (CT) characteristics of confluent fibrosis complicating liver cirrhosis, CT scans of 420 cirrhotic patients without hepatic malignancy who underwent hepatic transplantation were correlated with freshly resected whole liver specimens. In 59 patients, CT demonstrated 70 focal abnormalities corresponding to confluent fibrosis. The lesions were characterized by shape and location: 49 wedge-shaped lesions radiated from the porta hepatis, eight peripheral bandlike lesions were remote from the porta hepatis, and 13 lesions were seen as total lobar or segmental fibrosis. Associated volume loss was seen in 62 of the 70 lesions as retraction of the overlying hepatic capsule or total shrinkage of the segmental or lobar involvement. At plain CT, all 70 lesions were areas of lower attenuation than adjacent liver. At contrast material-enhanced CT, 51 of 64 lesions were iso-attenuating or minimally hypo-attenuating. The authors conclude that confluent fibrosis has a characteristic appearance at CT. Recognition of its characteristics may help radiologists differentiate confluent fibrosis from hepatic neoplasms in cirrhotic patients.

To investigate the efficacy and toxicity of definitive chemoradiotherapy (CRT) for elderly patients with locally advanced esophageal cancer. Twenty-two patients aged over 75 that performed definitive CRT were retrospectively reviewed. The regimen included concurrent CRT consisting of two cycles of chemotherapy (CTx) of platinum and 5-fluorouracil, and radiation therapy (RT) of 50-50.4 Gy (actual range: 45.4-71.4 Gy), and additional CTx where possible. Both CTx and RT were reduced in dose and field where necessary. The disease-free survival rate and the overall survival rate at 3 years were 33.3% ± 11.4% and 25.9% ± 10.8%. Grade 4 leukocytopenia and thrombocytopenia occurred in three (14%) and four (18%) patients. Treatment-related death was suspected in up to four (18%) patients at the most. Univariate analyses for disease-free survival showed that neither total radiation dose nor number of total cycles of CTx was significant. The pattern of relapse was predominantly more frequent in the intra-RT field than outside the RT field. For elderly patients, adverse events are frequent, and decreased organ reserve may cause treatment-related death. Reduction in CTx dose or RT field, appropriate only for two cycles of CTx, and careful monitoring may help to minimize toxicity. Physicians should not be too afraid of adverse events or be negative about CRT for elderly patients, as long as comorbidities and complications are managed carefully.

SUMMARYUsing time-series analysis, we investigated the monthly cholera incidence in Dhaka, Bangladesh during an 18-year period for its relationship to the sea surface temperature (SST) linked to El Niño, and to the sunspot number. Dominant periodic modes identified for cholera incidence were 11·0, 4·8, 3·5, 2·9, 1·6, 1·0 and 0·5 years. The majority of these modes, e.g. the 11·0-, 4·8-, 3·5-, 1·6- and 1·0-year modes, were essentially consistent with those obtained for the SST data (dominant modes: 5·1, 3·7, 2·5, 2·1, 1·5, 1·0 years) and the sunspot number data (dominant modes: 22·1, 11·1, 7·3, 4·8, 3·1 years). We confirmed that the variations of cholera incidence were synchronous with SSTs, and were inversely correlated to the sunspot numbers. These results suggest that the cholera incidence in Bangladesh may have been influenced by the occurrence of El Niño and also by the periodic change of solar activity.

Ovarian shielding allows ovarian recovery and normal birth in female hematopoietic SCT recipients undergoing TBI

A numerical analysis is presented for the dynamic behavior of thin conductive plates with a crack under both impulsive and constant magnetic fields which are perpendicular and parallel to the plate surface, respectively. On the assumption of two-dimensional currents and on the basis of small-bending-plate theory, and finite-element method is used for numerical analyses of the eddy current and the motion of the plate, respectively. The crack is found to open up in the transverse direction of the vibrating plate when it is perpendicular to the direction of the constant magnetic field. The Lorentz force is generated by interaction between the magnetic fields and the eddy current induced in the plate. If the Lorentz force is of sufficient magnitude, the crack may grow, which leads to fracture. >

Ablation plasma generated by an intense, pulsed ion beam was used for thin-film deposition of commercially interesting materials such as (Ba/sub x/, Sr/sub 1-x/)TiO/sub 3/. The deposition has been carried out in vacuum and with the substrate at room temperature. The deposited thin films were analyzed by using RES, AFM, SEM and XRD. The analytical results have shown that this deposition technique is applicable to many kinds of materials with very high deposition rate and low cost.

An electron cooler (EC) device for the Accumulator Cooler Ring (ACR) in the MUSES project is currently under development. The electron beam energy is varied from 30 keV to 250 keV with a maximum current of 4.1 A. An axial magnetic field of 0.2 T in a 3.6 m solenoid is chosen to satisfy the magnetization condition for the lightest ions and the expansion factor of 20 corresponds to the field of 4 T in the gun section. The details of the design and technological issues are discussed.

The authors describe the principle and design of an AC voltage sensor and a pressure sensor using a short column-type piezoelectric transducer. The sensors were designed, and a sinusoidal voltage measuring system or a mechanical stress detecting system using them was manufactured for trial. When electric stress was applied, this sensor accurately detected the mechanical strain of this piezoelectric transducer, on which a foil-type strain gauge was cemented. When the load with three rates of mechanical stress was applied to this sensor, the output voltage increased in proportion to the load with the rate of mechanical stress. >

Thin films of (Ba,Sr)TiO/sub 3/ (BST) and SiC were obtained by using the technology of intense, pulsed ion beam evaporation (IBE). The IBE takes advantage of high-temperature, high-density nature of the ablation plasmas generated by intense, pulsed ion beam. As a result, the thin films obtained by IBE are characterized by many special properties that can not be obtained by other thin-film deposition technologies. In this paper, we report the analytical results obtained by X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, the BST samples were analyzed by using the Sawyer-Tower circuit for dielectric constant measurement and the SiC samples were analyzed by the scratch test measurement.

The IBA proton therapy system selected by the Massachusetts General Hospital (MGH) to equip its new NPTC is presently under construction and test. This paper presents a progress report on the equipment construction. The cyclotron, as well as the rest of the equipment, are being progressively installed in the NPTC building. The acceptance tests of the whole system are foreseen for the end of 1997.

An RI beam factory project is proposed by the Institute of Physical and Chemical Research (RIKEN) as a next new facility for nuclear physics. The accelerator system for this project, consists of main 2 parts, one is superconducting ring cyclotron (SRC) and the other is a storage ring system named MUSES. An accumulator cooler ring (ACR) is a part of Multi-USe Experimental Storage rings (MUSES). It is used for the accumulation and cooling of the radioactive isotope (RI) beams which are produced by the beam from SRC and pass through a fragment separator. The large momentum spreads of these RI beams will be significantly reduced by the electron cooling and stochastic cooling devices in the ACR. Devices for multi-turn injection and RF stacking are also prepared in order to increase the beam current. The simulations and designs of these devices are presented in this report.

Precipitation of diluted Gastrografin (meglumine sodium amidotrizoate) occurred in the stomach during computed tomography (CT) examination in a 43-year-old man with fasting. Precipitation was not observed on the initial plain CT scan, but was demonstrated on the contrast-enhanced CT scan following the plain CT. Hyperacidity in the stomach might be promoted during CT examination and cause precipitation between scans.

Recently, troglitazone has emerged as an insulin sensitizer for the treatment of type II diabetes. However, its effect on skeletal muscle glucose use (SMGU) has not been studied.To investigate the effect of troglitazone on SMGU in patients with type II diabetes, we undertook skeletal muscle (18)F-FDG PET dynamic imaging under insulin clamping before and after administration of SMGU to 20 patients with type II diabetes. Data were compared with those for 12 age-matched healthy volunteers.The whole-body glucose disposal rate (GDR) was significantly lower in patients (29.9 +/- 9.83 micromol/min/kg) than in control subjects (55.6 +/- 16.5 micromol/min/kg, P0.01), as was the SMGU (patients, 3.27 +/- 2.17 micromol/min/kg; control subjects, 10.9 +/- 6.4 micromol/min/kg; P0.01). After the therapy, GDR significantly improved in patients (29.3 +/- 14.6 micromol/min/kg, P0.05), as did SMGU (5.06 +/- 2.11 micromol/min/kg, P0.05). When results for patients with and without hypertension were separately analyzed, a significant improvement in SMGU after troglitazone was seen in both normotensive and hypertensive patients (normotensive [n = 10]: baseline, 3.67 +/- 2.89 micromol/min/kg; after therapy, 5.28 +/- 2.61 micromol/min/kg; P0.05; hypertensive [n = 10]: baseline, 2.89 +/- 1.22 micromol/min/kg; after therapy, 4.72 +/- 1.39 micromol/min/kg; P0.05). GDR in patients with and without hypertension was significantly improved by troglitazone (normotensive: baseline, 17.9 +/- 10.2 micromol/min/kg; after therapy, 31.9 +/- 15.9 micromol/min/kg; P0.01; hypertensive: baseline, 39.6 +/- 15.1 micromol/min/kg; after therapy, 47.7 +/- 23.8 micromol/min/kg; P0.05). The plasma free fatty acid concentration during insulin clamping was not changed by troglitazone (baseline, 1.1 +/- 0.86 mEq/L; after therapy, 0.93 +/- 0.65 mEq/L; P = not significant).Troglitazone can improve whole-body insulin resistance through the improvement of SMGU but not through a decline in plasma free fatty acid concentration in patients with type II diabetes with or without hypertension.

The aim of this report is to introduce a flat-panel, self-scanning, solid-state diagnostic X-ray imaging device using complementary metal-oxide-semiconductor (C-MOS) arrays for real time digital X-ray imaging and to present findings on its performance.A device with a 5.12 cm by 5.12 cm sensor area was developed and tested. The device consists of a cesium iodide scintillator and C-MOS detector arrays. The detector arrays are composed of a regular arrangement of pixels (256x256), each of which is made of a C-MOS photodiode sensor coupled to a C-MOS FET (field effect transistor).A sampling speed of 30 frames per second and spatial resolution of 2.5 lines per mm were achieved. Noise level and maximum signal were 1.5 mV rms and 1.8 V, respectively.The C-MOS flat-panel sensor is a significant step in actualizing real-time X-ray imaging. A large area sensor needs to be fabricated for clincial use.

The need to draw regions of interest (ROIs) manually may reduce the convenience and reliability of estimating renal function from renal scintigraphy. We developed a semiautomated method to define ROIs for renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3) and evaluated the clinical applicability of the method to the estimation of renal function by camera-based methods.Dynamic renal scintigraphy with 99mTc-MAG3 was performed on 21 patients. An operator placed a large rectangular ROI over each kidney, a circular ROI within the liver, and a rectangular ROI between the kidneys. Using these ROIs, semiautomated renal ROIs were determined on the basis of the temporal changes in counts, in addition to the absolute counts, and a subrenal background ROI was automatically assigned for each renal ROI. Background-subtracted renograms were generated using these renal and subrenal ROIs, and renogram parameters were derived from the slope of the renogram and the area under the renogram. Clearance was calculated using the renogram parameters and equations determined previously with manual ROIs and correlated with clearance measured by a single-sample method. The relative function of the right kidney determined by the semiautomated method was compared with that determined by the manual method. Data processing was performed independently by another operator to assess interoperator reproducibility.ROIs defined by the semiautomated method were visually judged to be acceptable for clinical use in all patients with a wide range of renal function. Clearance was successfully predicted with the semiautomated ROIs (r = 0.968 using the slope of the renogram; r = 0.934 using the area under the renogram), and relative function calculated with the semiautomated ROIs was almost identical to that calculated with manual ROIs. There was almost complete concordance in absolute and relative function between the two operators.The semiautomated method can define ROIs for 99mTc-MAG3 renal scintigraphy with limited operator intervention. Camera-based methods using the semiautomated ROIs allow estimation of renal function with high accuracy and little interoperator variability and are suggested to be suitable for clinical use.

Blood and radiologic tests are frequently used for diagnosis of invasive pulmonary aspergillosis, but it remains unknown which is more useful for its early diagnosis. Aim of the study was to compare usefulness of computed tomographic (CT) scan of chest, latex agglutination (LA) test and determination of plasma (1--3)-beta-D-glucan (BDG) levels for early diagnosis of invasive pulmonary aspergillosis (IPA).We treated 215 consecutive patients who underwent cytotoxic chemotherapy. From initiation of chemotherapy until death or discharge, blood samples were taken weekly and subjected to LA and BDG tests. We performed chest CT scans when patients had any signs of pulmonary infection or an antibiotic-resistant fever.Of the 215 patients, 30 (14. 0%) were diagnosed as having IPA. In sixteen cases the diagnosis was definite and in 14 it was suspected. In patient-based analysis, sensitivities of LA and BDG were 44% and 63%, respectively. Sensitivity tended to be lower in patients with IPA localized to the lung than those with disseminated invasive aspergillosis. Specificities were 93% and 74%, respectively. Either a halo or an air-crescent was observed in 7 of the 16 patients with IPA, and all of the IPA patients showed some abnormal signs on chest CT scans. On average, CT scan signs preceded a positive LA test by 7.1 days and a positive BDG assay by 11.5 days. In 6 of the 11 patients who became positive for either LA or BDG assay, CT scan signs preceded the positive results by more than seven days.Chest CT scan is more beneficial than the blood tests and X-ray for early diagnosis of IPA.

Coronary microangiopathy is a major complication in diabetics. However, the presence of independent factors in association with coronary microangiopathy in patients with non-insulin-dependent diabetes mellitus (NIDDM) or the difference in coronary microangiopathy between diabetics with coronary artery disease (CAD) and those with microvascular angina is unclear.Nineteen patients with NIDDM and microvascular angina, 18 patients with NIDDM and CAD, and 17 age-matched control subjects were studied. Myocardial segments that were perfused by angiographically normal coronary arteries were studied. The baseline myocardial blood flow (MBF) and the MBF during dipyridamole administration were measured using PET and 13N-ammonia, after which the myocardial flow reserve (MFR) was calculated to assess coronary microangiopathy.The baseline MBF was comparable among NIDDM patients with microvascular angina, NIDDM patients with CAD, and control subjects. However, the MBF during dipyridamole administration was significantly lower in NIDDM patients with microvascular angina (126 +/- 42.7 mL/min/100 g) than that in either NIDDM patients with CAD (210 +/- 70.1 mL/min/100 g; P0.01) or control subjects (293 +/- 159 mL/min/100 g; P0.01), as was the MFR (NIDDM with microvascular angina, 1.90 +/- 0.73; NIDDM with CAD, 2.59 +/- 0.81 [P0.01]; control subjects, 3.69 +/- 1.09 [P0.01]). Multivariate stepwise regression analysis showed that, among the factors considered, glycemic control was independently related to the MFR (r = 0.838; P0.05).Glycemic control appears to be essential for coronary microangiopathy in NIDDM.

Correction for soft-tissue attenuation is required to evaluate absolute renal function by a camera-based method, and an estimate of renal depth and an attenuation coefficient are commonly used for attenuation correction. The first goal of this study was to develop formulas for the calculation of renal depth in both children and adults. The second goal was to optimize the attenuation coefficient for the estimation of renal accumulation of a 99mTc-labeled agent.Renal depth was measured by CT in 74 children and 232 adults and compared with the depth calculated using previously published equations. Multiple stepwise linear regression analysis was conducted using data from children and adults together, and new formulas to calculate renal depth were derived. Using the resulting equations, percentage renal uptake at 2-2.5 min was computed from 99mTc-diethylenetriamine pentaacetic acid (DTPA) renography in 40 children and 92 adults. Percentage renal uptake was assessed using various values of an attenuation coefficient, and an optimized attenuation coefficient was determined to maximize the correlation coefficient between percentage renal uptake and glomerular filtration rate (GFR) measured from 2 blood samples.Although the previously published equations appeared to be acceptable in predicting adult renal depth, they substantially underestimated pediatric renal depth. Renal depth (D, cm) was shown by stepwise regression analysis to depend on the ratio of body weight (W, kg) to body height (H, cm) and was successfully calculated in both children and adults using the derived equations (right: D = 16.778 x W/H + 0.752; left: D = 16.825 x W/H + 0.397). The correlation coefficient between percentage renal uptake of 99mTc-DTPA and measured GFR varied substantially according to the attenuation coefficient used and was the highest (0.947) with an attenuation coefficient of 0.087/cm.The equations presented here enabled estimation of renal depth irrespective of the patient's age. Attenuation correction using these equations and the optimized attenuation coefficient appears to aid in evaluating renal accumulation and, consequently, renal function in both children and adults.

Dopamine dose-dependently reduced the viable cell number of both human salivary gland tumor HSG and oral squamous cell carcinoma HSC-2, HSC-4, and NA cells. CoCl2 significantly reduced both the cytotoxic activity and radical intensity of dopamine (determined by ESR spectroscopy). Dopamine produced DNA fragments (demonstrated by TUNEL method) and induced degradation of cytokeratin by activated caspase in HSG cells (detected by an immunocytochemical method, using a specific M30 monoclonal antibody). FACS analysis demonstrated that dopamine induced DNA fragmentation, a biochemical hallmark of apoptosis, in human promyelocytic leukemia HL-60 cells. The addition of catalase did not prevent the apoptosis-inducing activity of dopamine, reducing the possibility of the involvement of H2O2 for dopamine-induced apoptosis. Dopamine transiently induced p38 mitogen-activated protein kinase (MAP kinase) phosphorylation. However, an inhibitor of p38 MAP kinase phosphorylation, SB203680, failed to inhibit the dopamine-induced apoptosis. These data suggest that p38 phosphorylation at an early stage may not be a causative event for apoptosis.

The ultimate goal of radiation therapy is to confine a high dose to the target area while sparing the surrounding normal structures in order to increase the delivered dose and decrease the likelihood of organ injuries. In Japan, the rotational conformal technique, which is a combination of gantry rotation and dynamic movement of multi-leaf collimators (MLC), has been widely used as a standard method for high-precision radiation therapy. The non-coplanar technique in which radiation beams are given in three dimensions has the advantage of dose concentration as well as organ sparing. In intensity modulated radiotherapy (IMRT), an uneven intensity map within a beam is generated with various methods such as "sliding window technique" and "stop and shoot technique". Several intensity modulated beams are combined to create arbitrary dose distribution including concave distribution. Although a substantial number of proton therapy facilities are planned in this country, IMRT should be considered as a competitive rival from the viewpoint of cost-benefit analysis as well as clinical effectiveness.

The deadtime of a single-crystal gamma camera depends on the scattering condition, and differs among patients. The aim of this study was to estimate deadtime in posterior abdominal imaging. Radionuclide angiography of the posterior abdominal view was performed in 23 patients with a point source in the field-of-view, and temporal changes in count loss were assessed. The deadtime for each patient was calculated based on the count loss for the point source. The estimated deadtime ranged from 7.83-12.52 microsec, and was significantly correlated with the ratio of body weight in kg to body height in cm (y=13.143x+5.595, r=0.852, p0.001). Count loss was successfully corrected using the deadtime predicted with the regression equation. In conclusion, the deadtime in posterior abdominal imaging can be predicted for each patient from the body weight and body height. The predicted deadtime may aid in improving the reliability of quantitative measurements by scintigraphic techniques.

Abnormal heart and skeletal muscle 18F-fluorodeoxyglucose (FDG) uptake in patients with insulin resistance has been demonstrated. Although the existence of whole-body insulin resistance has been reported in hypertriglyceridemics, its specific role in heart and skeletal muscle FDG uptake in hypertriglyceridemics has not been clarified.We compared heart and skeletal muscle FDG uptake using PET and the whole-body glucose disposal rate (GDR) during insulin clamping in 17 hypertriglyceridemics and 12 age-matched control subjects to increase our knowledge of whole-body insulin resistance and its relationship to heart and skeletal muscle FDG uptake in hypertriglyceridemics.GDR was significantly reduced in hypertriglyceridemics compared with control subjects (4.50 +/- 1.37 mg/min/kg versus 10.0 +/- 2.97 mg/min/kg, P = 0.00001), as were the skeletal muscle FDG Ki = (k1 x k3)/(k2 + k3) (SFKi: 0.007 +/- 0.003 mL/min/g versus 0.018 +/- 0.01 mL/min/g, P = 0.0001) and skeletal muscle FDG uptake ([SMFU] 0.725 +/- 0.282 mg/min/100 g versus 1.86 +/- 1.06 mg/min/100 g, P = 0.00023). However, myocardial FDG Ki (MFKi) tended to be reduced in hypertriglyceridemics compared with that in control subjects (0.062 +/- 0.017 mL/min/g versus 0.068 +/- 0.015 mL/min/g), but the difference was statistically insignificant (P = 0.3532). Moreover, myocardial FDG uptake (MFU) in hypertriglyceridemics (6.47 +/- 1.72 mg/min/100 g) tended to be reduced compared with that in control subjects (6.97 +/- 1.73 mg/min/100 g), but the difference was statistically insignificant (P = 0.4485). GDR was significantly correlated with SFKi (r = 0.69, P = 0.0022), SMFU (r = 0.612, P = 0.009), MFKi (r = 0.57, P = 0.0174) and MFU (r = 0.505, P = 0.0385) in hypertriglyceridemics.Both heart and skeletal muscle glucose utilization were related to insulin resistance in hypertriglyceridemics. However, the less severe reduction in MFU (compared with SMFU) suggests that myocardium may have a mechanism to oppose insulin resistance in hypertriglyceridemics.

We have developed an X-ray magnification radiographic system incorporating a microfocus X-ray tube and an imaging plate in order to analyze the trabecular structure and mineral content of rat bone. Femoral bones of control, ovariectomy, and leuprorelin acetate depot rat groups were extracted and tested after the animals were sacrificed. Eleven water-equivalent phantoms, which contained hydroxyapatite at a density of 0 to 400 mg/cm3, were set around each femur and radiographed at the same time. The mean read-out signal intensity of the region of interest in the femur was converted to bone mineral density expressed in hydroxyapatite density through the use of a calibration curve relating the signal intensity to the hydroxyapatite density of the phantoms. The bone mineral density of the ovariectomy group was significantly lower than that of the control group, and no differences were found between the control and the leuprorelin acetate depot group. The present system is thought to be useful for quantitative evaluation of the mineral density of the rat femur.

To develop a camera-based method for evaluating renal function with 99mTc-mercaptoacetyltriglycine (MAG3), we examined the relationship between various renogram parameters and 99mTc-MAG3 clearance.Twenty-one patients underwent renal scintigraphy with 99mTc-MAG3. Eighty 3-s frames were obtained after the bolus injection of 250 MBq tracer, followed by the collection of 52 30-s frames. Regions of interest were drawn for the kidneys, perirenal background areas and subrenal background areas, and background-subtracted renograms were generated. Renal accumulation at 0.5-1.5, 0.5-2, 1-2, 1-2.5 and 1.5-2.5 min after tracer arrival in the kidney was calculated as area under the background-subtracted renogram, and percent renal uptake was obtained after correction for soft-tissue attenuation and injected dose. The slope of the renogram was determined for the same segments used in calculating area under the renogram, and slope index was computed as slope corrected for attenuation and injected dose. Percent renal uptakes and slope indices were correlated by linear regression analysis with 99mTc-MAG3 clearance measured using a single blood sampling method.Among the values of percent renal uptake, the value obtained at 1.5-2.5 min using the perirenal background correlated best with 99mTc-MAG3 clearance. The slope index at 0.5-1.5 or 0.5-2 min using the subrenal background provided better accuracy than percent renal uptake for predicting clearance. There were no substantial differences in the relative function of the right kidney between the methods using percent renal uptake and slope index.99mTc-MAG3 clearance can be assessed with acceptable accuracy by a camera-based method. The method based on the slope of the renogram may replace the one based on the area under the renogram in evaluating renal function from 99mTc-MAG3 renograms.

Required ultracentrifugal time for condensing a solution by ultracentrifuge with an angle rotor or a swing rotor was estimated by considering the calculated distribution of concentration in an ultracentrifugal tube. From the calculated distribution of the concentration a free boundary between solvent and solution was found in the ultracentrifugal tube under the condition that t*>0.25. A condense constant was newly defined as the ratio of the mean concentration in the ultracentrifugal tube after removing the solvent to the concentration of initial solution. The equation determining the required ultracentrifugal time for condensing a solution up to a given condense constant is derived and solved numerically. The required ultracentrifugal time for an angle rotor was shorter than that for a swing rotor.

Statistical parametric mapping (SPM) has been developed by Friston et al. to analyze focal changes in regional cerebral blood flow (rCBF) induced by brain activation. This automated and objective approach has the potential of being applied to single photon emission computed tomography (SPECT) image data sets. This study evaluated an automated analysis of N-isopropyl-p[123I]iodoamphetamine SPECT (123I-IMP) imaging in patients with dementia of Alzheimer's type (DAT) using statistical parametric mapping '95 (SPM'95). Eighteen patients with clinically diagnosed mild to severe DAT who were classified into two groups and ten normal control subjects were studied. The SPECT device used was a triple-headed rotation gamma camera. All images were transformed into the standard anatomical space of the stereotaxic brain atlas of Talairach and Tournoux, and then smoothed. Statistical analyses were made between severe DAT, mild DAT and normal control groups. SPM analysis of 123I-IMP SPECT images revealed that the parietotemporal association areas and posterior cingulate gyri of both cerebral hemispheres were significantly decreased in CBF in mild DAT group compared to normal controls. In comparison of DAT groups, the right hippocampal area and basal forebrain were significantly decreased in CBF in severe DAT group. In conclusion, these results obtained by SPM analysis of SPECT images suggested that the right hippocampal area and basal forebrain followed the parietotemporal association areas and posterior cingulate gyri in the reduction of the rCBF in patients with DAT.

In this article, the MR imaging appearance of various aspects of liver cirrhosis (macroscopic morphologic changes and focal manifestations) is reviewed with particular reference to the premalignant nodular lesions that should be differentiated from hepatocellular carcinoma. MR imaging findings reflecting portal hypertension are also presented.