Objective： To evaluate the efficacy of double-phase contrast material-enhanced computed tomography （CT） in assessing no-surgical treatment response in bronchogenic carcinoma preliminarily. Methods： 52 patients wit...Objective： To evaluate the efficacy of double-phase contrast material-enhanced computed tomography （CT） in assessing no-surgical treatment response in bronchogenic carcinoma preliminarily. Methods： 52 patients with bronchogenic carcinoma after no-surgical treatment underwent double-phase contrast material-enhanced computed tomography. Two spiral CT scans were obtained at 25 and 90 seconds respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 mUs by using an autoinjector. Precontrast and postcontrast attenuation on every scan was recorded and peak height was calculated. Enhancement pattern was evaluated on the images obtained at 25 and 90 seconds after injection of contrast medium. Results： Precontrast attenuation, postcontrast attenuation at 25 and 90 seconds were 42.20 ± 7.43 Hu, 57.35 ± 10.09 Hu and 71.85 ±12.45 Hu, respectively. No statistically significant difference in precontrast attenuation was found between our results in the study and the results in our old study （mean precontrast attenuation 40.70 Hu） which was obtained in cases before therapy （t = 1.455, P = 0.152 〉 0.05）. Peak height of bronchogenic carcinoma after no-surgical treatment （29.46 ±10.85 Hu） were significantly lower than that of bronchogenic carcinoma before therapy obtained in our old study （mean peak height 35.79 Hu; t = 4.206, P = 0.001 〈 0.05）. 32 of 52 cases showed homogeneous enhancement at 90 seconds. Of the 32 cases, there were 21 with inhomogeneous enhancement, 7 with inhomogeneous enhancement, 2 with central enhancement and 2 with peripheral enhancement at 25 seconds. Conclusion： Bronchogenic carcinoma after no-surgical treatment shows a gradual increase to the peak height after administration of contrast material. Peak heights can reflect the blood supply of bronchogenic carcinoma and might be index for evaluation of no-surgical treatment response in bronchogenic carcinoma.展开更多
Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the unifo...Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.展开更多
文摘Objective： To evaluate the efficacy of double-phase contrast material-enhanced computed tomography （CT） in assessing no-surgical treatment response in bronchogenic carcinoma preliminarily. Methods： 52 patients with bronchogenic carcinoma after no-surgical treatment underwent double-phase contrast material-enhanced computed tomography. Two spiral CT scans were obtained at 25 and 90 seconds respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 mUs by using an autoinjector. Precontrast and postcontrast attenuation on every scan was recorded and peak height was calculated. Enhancement pattern was evaluated on the images obtained at 25 and 90 seconds after injection of contrast medium. Results： Precontrast attenuation, postcontrast attenuation at 25 and 90 seconds were 42.20 ± 7.43 Hu, 57.35 ± 10.09 Hu and 71.85 ±12.45 Hu, respectively. No statistically significant difference in precontrast attenuation was found between our results in the study and the results in our old study （mean precontrast attenuation 40.70 Hu） which was obtained in cases before therapy （t = 1.455, P = 0.152 〉 0.05）. Peak height of bronchogenic carcinoma after no-surgical treatment （29.46 ±10.85 Hu） were significantly lower than that of bronchogenic carcinoma before therapy obtained in our old study （mean peak height 35.79 Hu; t = 4.206, P = 0.001 〈 0.05）. 32 of 52 cases showed homogeneous enhancement at 90 seconds. Of the 32 cases, there were 21 with inhomogeneous enhancement, 7 with inhomogeneous enhancement, 2 with central enhancement and 2 with peripheral enhancement at 25 seconds. Conclusion： Bronchogenic carcinoma after no-surgical treatment shows a gradual increase to the peak height after administration of contrast material. Peak heights can reflect the blood supply of bronchogenic carcinoma and might be index for evaluation of no-surgical treatment response in bronchogenic carcinoma.
基金supported by the National Natural Science Foundation of China(Grant No.51576187)Fundamental Research Funds for the Central Universities(Grant No.WK2090130016)
文摘Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.
