60 research outputs found

    MR imaging of renal cell carcinoma: associations among signal intensity, tumor enhancement, and pathologic findings.

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    The purpose of this study was to compare the MR characteristics of renal cell carcinomas against histologic findings and to assess the correlations among signal intensity, tumor enhancement, and pathologic findings. Fifty-four patients (56 lesions) were examined by MR imaging and then underwent partial or radical nephrectomy. The pathologic diagnosis of all lesions was renal cell carcinoma. All MR examinations were performed as dynamic studies using the same 1.5-T scanner. MR characteristics were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation.</p

    Anti-cancer Approach with NK4 and Anti-angiogenic Mechanism of NK4: NK4 Gene Therapy for Malignant Mesothelioma

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    Division of Tumor Dynamics and Regulatio

    Kinematic magnetic resonance imaging (MRI) of the normal shoulder: assessment of the shapes and signals of the superior and inferior labra with abductive movement using an open-type imager.

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    A preliminary study was conducted to evaluate the superior and inferior glenoid labra with abductive movement using an open-type MR unit in asymptomatic healthy volunteers. Both fast low angle shot (FLASH) and turbo spin echo (TSE) images were obtained to evaluate the shapes of both the superior and inferior labra, as well as to assess changes in signal at these sites. As the abduction angle was increased, the shape of the superior labrum changed from round or triangular to crescentic and a higher signal was frequently seen. At an abduction angle of 150 degrees, an increase in signal was seen in one-half of the superior labra; this increase was noted more frequently in volunteers over 40 years of age. In some of the superior labra, the increase in signal seen at 150 degrees abduction disappeared on subsequent images obtained at 0 degrees abduction. Hence, the increase in signal was considered to be a reversible change. The shape of the inferior labrum tended to change from crescentic to triangular or round. An increase in signal in the inferior labrum was unrelated to the abduction angle. Abductive kinematic studies using an open-type MR unit provides information about the morphology of the superior and inferior labra, as well as information about signal changes occurring at these sites.</p

    GRENE-TEA Model Intercomparison Project (GTMIP): Stages 1 & 2

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    第6回極域科学シンポジウム分野横断セッション:[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日(木) 国立極地研究所 2階 大会議

    Hydrothermal Activity Inferred from Comprehensive Observation of Unrest in Adatara Volcano

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    Estimation of Leaf Area Index in a Mountain Forest of Central Japan with a 30-m Spatial Resolution Based on Landsat Operational Land Imager Imagery: An Application of a Simple Model for Seasonal Monitoring

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    An accurate estimation of the leaf area index (LAI) by satellite remote sensing is essential for studying the spatial variation of ecosystem structure. The goal of this study was to estimate the spatial variation of LAI over a forested catchment in a mountainous landscape (ca. 60 km2) in central Japan. We used a simple model to estimate LAI using spectral reflectance by adapting the Monsi-Saeki light attenuation theory for satellite remote sensing. First, we applied the model to Landsat Operational Land Imager (OLI) imagery to estimate the spatial variation of LAI in spring and summer. Second, we validated the model’s performance with in situ LAI estimates at four study plots that included deciduous broadleaf, deciduous coniferous, and evergreen coniferous forest types. Pre-processing of the Landsat OLI imagery, including atmospheric correction by elevation-dependent dark object subtraction and Minnaert topographic correction, together with application of the simple model, enabled a satisfactory 30-m spatial resolution estimation of forest LAI with a maximum of 5.5 ± 0.2 for deciduous broadleaf and 5.3 ± 0.2―for evergreen coniferous forest areas. The LAI variation in May (spring) suggested an altitudinal gradient in the degree of leaf expansion, whereas the LAI variation in August (mid-summer) suggested an altitudinal gradient of yearly maximum forest foliage density. This study demonstrated the importance of an accurate estimation of fine-resolution spatial LAI variations for ecological studies in mountainous landscapes, which are characterized by complex terrain and high vegetative heterogeneity
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