Our purpose was to evaluate diffusion-weighted (DW) echo-planar MRI in differentiating between brain abscess and tumour. We examined two patients with surgically confirmed pyogenic brain abscess and 18 with metastatic brain tumours or high-grade glioma, using a 1.5 T system. The apparent diffusion coefficient (ADC) of each necrotic or solid contrast-enhancing lesion was measured with two different b values (20 and 1200 s/mm2). All capsule-stage brain abscesses (4 lesions) and zones of cerebritis (2 lesions) were identified on high-b-value DWI as markedly high-signal areas of decreased ADC (range, 0.58-0.70 [(10-3 mm2/s; mean, 0.63)]). All cystic or necrotic portions of brain tumours (14 lesions) were identified on high-b-value DWI as low-signal areas of increased ADC (range, 2.20-3.20 [(10-3 mm2/s; mean, 2.70)]). Solid, contrast-enhancing portions of brain tumours (19 lesions) were identified on high-b-value DWI as high-signal areas of sightly decreased or increased ADC (range, 0.77-1.29 [(10-3 mm2/s; mean, 0.94)]). Our preliminary results indicate that DW echo-planar MRI be used for distinguishing between brain abscess and tumour.

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Stable blast furnace operation is required to reduce energy consumption in iron and steelmaking industry. For the stable blast furnace operation, precise controlled drainage is one of the important factors. However, the effects of the various in-furnace conditions on the stable operation were not examined well. Therefore, in this work, basic characteristic features of drainage in a blast furnace hearth were examined.Two-and three-dimensional mathematical model were developed based on the finite difference method to simulate molten iron and slag flow in a hearth of a blast furnace. Pressure drop evaluation model in a taphole was developed to reflect pressure variation in a blast furnace hearth on drainage rate of molten iron and slag for the three-dimensional mathematical model.The two-dimensional mathematical model results were validated with measured interfaces shapes obtained using an experimental model. The three-dimensional mathematical model results were validated with measured total, iron and slag drainage rate of Chiba No. 6 blast furnace. The results indicate that the drainage behavior and residual iron and slag volume were affected by the conditions in the hearth. The taphole conditions dominate the total drainage rate under the term of assumed blast furnace conditions. In order to reduce the residual slag volume, the taphole diameter change during the tap should be controlled. The decrease of the coke diameter causes increase of the residual slag volume, decrease of the residual iron volume.KEY WORDS: iron and slag flow; residual slag volume; numerical simulation; VOF method; blast furnace hearth; ironmaking.faces shapes of immiscible fluids having different properties. Two-dimensional Mathematical ModellingThe governing equations for fluid flow used in the twodimensional mathematical model are based on the HSMAC method, 8) ... (3) where u is the horizontal velocity (m/s), v is vertical velocity (m/s), x and y are coordinates (m), t is time (s), r is density of fluids (kg/m 3 ), p is pressure of fluids (Pa), m is viscosity (Pa · s), g is acceleration due to gravity (m/s 2 ), and S is an interaction force between fluid and 2 flat parallel plates (m/s 2 ). In the two-dimensional mathematical model, gas, slag and iron were treated as one fluid having local properties, which correspond to each phase. Representation of InterfacesFor the determination of the fluid properties in each computational cell, it is necessary to compute the proportion of gas, iron and slag in each cell. Therefore, gas-slag and slag-iron interfaces should be identified exactly. To distinguish the interfaces, the VOF method 9) was applied for the calculation of interfaces (gas-slag, slag-iron). Generally, the VOF method is used to track free boundaries in two-or three-dimensional meshes. Although, in this work, VOF is also used to identify slag-iron interface, as shown in Fig. 1. A unit value of VOF 1 would correspond to a cell full of liquid. A unit value of VOF 2 would correspond to a cell full of iron. Cells with VOF 2 values betw...

IntroductionThe aim of this study was to clarify the effectiveness of various imaging modalities and characteristic imaging features in the screening of IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), and to show the differences in the imaging features between IgG4-DS and Sjögren’s syndrome (SS).MethodsThirty-nine patients with IgG4-DS, 51 with SS and 36 with normal salivary glands were enrolled. Images of the parotid and submandibular glands obtained using sonography, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively analyzed. Six oral and maxillofacial radiologists randomly reviewed the arranged image sets under blinded conditions. Each observer scored the confidence rating regarding the presence of the characteristic imaging findings using a 5-grade rating system. After scoring various findings, diagnosis was made as normal, IgG4-DS or SS, considering all findings for each case.ResultsOn sonography, multiple hypoechoic areas and hyperechoic lines and/or spots in the parotid glands and obscuration of submandibular gland configuration were detected mainly in patients with SS (median scores 4, 4 and 3, respectively). Reticular and nodal patterns were observed primarily in patients with IgG4-DS (median score 5). FDG-PET/CT revealed a tendency for abnormal 18F-FDG accumulation and swelling of both the parotid and submandibular glands in patients with IgG4-DS, particularly in the submandibular glands. On MRI, SS had a high score regarding the findings of a salt-and-pepper appearance and/or multiple cystic areas in the parotid glands (median score 4.5). Sonography showed the highest values among the four imaging modalities for sensitivity, specificity and accuracy. There were significant differences between sonography and CT (p = 0.0001) and between sonography and FDG-PET/CT (p = 0.0058) concerning accuracy.ConclusionsChanges in the submandibular glands affected by IgG4-DS could be easily detected using sonography (characteristic bilateral nodal/reticular change) and FDG-PET/CT (abnormal 18F-FDG accumulation). Even inexperienced observers could detect these findings. In addition, sonography could also differentiate SS. Consequently, we recommend sonography as a modality for the screening of IgG4-DS, because it is easy to use, involves no radiation exposure and is an effective imaging modality.

The Stafne's bone defects are thought to be caused by the dislocated submandibular gland. The differences between the two types might occur as a result of a different location of the submandibular gland.

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JFE Steel Corporation developed the hydrogen-based gas fuel injection technology for sintering machines to improve sinter quality without increasing coke breeze ratio. With the technology, it is possible to extend the temperature zone between 1 200°C and 1 400°C by injecting the gaseous fuel from the top surface of the sintering machine as a partial substitute for coke breeze. Theoretical and experimental studies were carried out to verify the effect of the gaseous-fuel injection technology on pore structure in the sinter cake with the X-ray CT scanner and sintering pot test.It is important to hold the temperature between 1 200°C and 1 400°C in order to produce high strength and high reducibility sinter. The liquid phase ratio can be increased with extending the proper temperature zone by applying the gaseous fuel injection technology. The increase in liquid phase ratio promotes the combination of pores (1-5 mm) and sinter strength is improved. At the same time, the pores over 5 mm growth are promoted and the permeability is improved in the sintering bed. Moreover, the low-temperature sintering process depresses the iron ore self-densification. Micro pores under 1 μm remain in unmelted ores and improve sinter reducibility. As a result, the technology enables to improve the pore structure in the sinter cake and sinter quality.The technology was put into commercial operation at Keihin No. 1 sinter plant in January 2009 and stable operation has continued up to the present. As a result, the energy efficiency in the sintering process is greatly improved, and it has been achieved to reduce CO2 emissions by a maximum of approximately 60 000 t/year at Keihin No. 1 sinter plant.

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