165 research outputs found

    Dual-Energy CTを用いた肺血液量画像の定量的評価:急性肺血栓塞栓症患者に対する定量的重症度評価

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    BACKGROUND:Regional iodine distribution assessment on dual-energy computed tomography (DECT) has been suggested as useful for management of acute pulmonary thromboembolism (APTE) patients. However, no reported studies have made a direct comparison between quantitatively assessed DECT and right-to-left ventricular (RV/LV) ratio on CT for differentiation of right heart dysfunction (RHD) from non-right heart dysfunction (NRHD) in APTE patients. PURPOSE:To determine the capability of DECT for differentiation of RHD from NRHD in APTE patients. MATERIAL AND METHODS:Thirteen APTE patients underwent DECT and echocardiography at onset of APTE. Patients were divided into RHD (n = 7) and NRHD (n = 6) groups based on echocardiography. A normalized lung perfused blood volume map was generated, and two kinds of overall perfusion (OP) index were determined, one placed over each lung field (OP index A) and as the average from six regions of interest (ROIs) placed over each lung field (OP index B). The heterogeneity index was also determined as the standard deviation for the six ROIs. RV/LV ratio evaluations were also performed. To assess differences between the two groups, each index was statistically compared with the Mann-Whitney U test. The receiver-operating curve-based positive test was then performed to determine the feasible threshold value for dividing patients into the two groups. Finally, differentiation capabilities of the indexes were compared using McNemar's test. RESULTS:Significant differences between the two groups were found for both OP indexes and RV/LV ratio (P < 0.05). For each of the feasible threshold values, accuracy of each OP index with and without RV/LV ratio was better than that of the RV/LV ratio. CONCLUSION:Quantitative DECT has good potential for differentiation of APTE patients with and without right heart dysfunction.博士(医学)・乙第1350号・平成26年12月3日© The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

    13CO(J=1-0) On-the-fly Mapping of the Giant HII Region NGC 604: Variation in Molecular Gas Density and Temperature due to Sequential Star Formation

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    We present 13CO(J=1-0) line emission observations with the Nobeyama 45-m telescope toward the giant HII region NGC 604 in the spiral galaxy M 33. We detected 13CO(J=1-0) line emission in 3 major giant molecular clouds (GMCs) labeled as GMC-A, B, and C beginning at the north. We derived two line intensity ratios, 13CO(J=1-0)/12CO(J =1-0), R13/12, and 12CO(J=3-2)/12CO(J =1-0), R31, for each GMC at an angular resolution of 25" (100 pc). Averaged values of R13/12 and R31 are 0.06 and 0.31 within the whole GMC-A, 0.11 and 0.67 within the whole GMC-B, and 0.05 and 0.36 within the whole GMC-C, respectively. In addition, we obtained R13/12=0.09\pm0.02 and R31=0.76\pm0.06 at the 12CO(J=1-0) peak position of the GMC-B. Under the Large Velocity Gradient approximation, we determined gas density of 2.8 \times10^3 cm^-3 and kinetic temperature of 33+9-5 K at the 12CO(J=1-0) peak position of the GMC-B. Moreover, we determined 2.5 \times10^3 cm^-3 and 25\pm2 K as averaged values within the whole GMC-B. We concluded that dense molecular gas is formed everywhere in the GMC-B because derived gas density not only at the peak position of the GMC but also averaged over the whole GMC exceeds 10^3 cm^-3. On the other hand, kinetic temperature averaged over the whole GM-B, 25 K, is significantly lower than that at the peak position, 33 K. This is because HII regions are lopsided to the northern part of the GMC-B, thus OB stars can heat only the northern part, including the 12CO(J=1-0) peak position, of this GMC.Comment: 16 pages, 7 figures, PASJ in pres

    Feasibility and Efficacy of Definitive Radiotherapy with 66 Gy and Concurrent Carboplatin-Paclitaxel Chemotherapy for Stage III Non-Small Cell Lung Cancer.

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    Purpose/Objectives : This study was conducted to assess the feasibility and efficacy of definitive radiotherapy (RT) with a total dose of 66 Gy and concurrent carboplatin-paclitaxel chemotherapy for patients (pts) with stage Ⅲ non-small celllung cancer. Materials/Methods : Between April 2007 and December 2013,99 pts with non-small cell lung cancer were treated using RT with concurrent carboplatin-paclitaxel chemotherapy in our hospital. Sixty-eight of them received RT with a total dose of 66 Gy. We analyzed 46 Stage Ⅲ pts who had been treated with RT using three-dimensional radiotherapy treatment planning. The prophylactic mediastinal lymph nodes were included in the clinical target volume for RT. The survival rate after the start of RT was estimated using the Kaplan-Meier method. We estimated the cumulative local failure and distant metastasis rates with the Fine-Gray method. Adverse events were evaluated according to the CTCAE (v.4.0). Results : The median age of the pts was 70.9 (52.8-78.7) years old (y.o.). The performance status (PS) of each pt was fairly good (ECOG PS 0: 25, PS 1: 20, PS 3:1), and their clinical stages (UICC 7th) were twenty-nine Ⅲ A and seventeen Ⅲ B. Diagnoses were pathologically confirmed in 32 pts. The median follow-up period was 35.7 (2.0-82.2) months among all pts, and 55.9 (40.1-82.2) months among survivors. The 3- and 5-year Kaplan-Meier overall survival rates were 52.2 and 34.0%,respectively, and the median survival time was 36.6 months. The 3- and 5-year Kaplan-Meier progression-free survival rates were 29.1 and 21.9%,respectively, and the median progression-free survival time was 9.9 months. The 5-year local failure rate was 37.6%, and the 5-year distant metastasis rate was 49.7%. Sixteen (34.8%) pts required steroid administration because of radiation pneumonitis (CTCAE Grade 2 or higher) and two of them died (Grade 5). No other severe non-hematologic toxicity (Grade 3 or higher) was observed. Conclusion : These results suggest that definitive RT with a total dose of 66 Gy and concurrent carboplatin-paclitaxel chemotherapy is feasible and may be promising for pts with Stage Ⅲ non-small cell lung cancer

    An optical transition-edge sensor with high energy resolution

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    Optical transition-edge sensors have shown energy resolution for resolving the number of incident photons at the telecommunication wavelength. Higher energy resolution is required for biological imaging and microscope spectroscopy. In this paper, we report on a Au/Ti (10/20 nm) bilayer TES that showed high energy resolution. This was achieved by lowering the critical temperature Tc to 115 mK and the resultant energy resolution was 67 meV full width at half maximum (FWHM) at 0.8 eV. When Tc was lowered to 115 mK, the theoretical resolution would scaled up to 30 meV FWHM, considering that the typical energy resolution of optical TESs is 150 meV and Tc is 300 mK. To investigate the gap between the theoretical expectation (30 meV) and the measured value (67 meV), we measured its complex impedance and current noise. We found excess Johnson noise in the TES and an excess Johnson term M was 1.5 at a bias point where the resistance was 10% of normal resistance. For reference, the TES was compared with a TES showing typical energy resolution (156 meV FWHM). We will discuss what improved the energy resolution and what might have been the limiting factor on it
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