目的评价64排螺旋CT联合Simplant软件使用不同管电流低剂量扫描方案的临床价值。方法选取临床需要种植牙术前评估行64排CT扫描的214例成年患者,其中男性128例,女性86例,随机分为3组,使用Philips Brilliance 64排螺旋CT,管电压固定(120 k...目的评价64排螺旋CT联合Simplant软件使用不同管电流低剂量扫描方案的临床价值。方法选取临床需要种植牙术前评估行64排CT扫描的214例成年患者,其中男性128例,女性86例,随机分为3组,使用Philips Brilliance 64排螺旋CT,管电压固定(120 k V),分别以250 m As,50 m As,35 m As管电流扫描,双盲法测量各组重建图像的噪声,评价图像质量、结合Simplant软件的效果及解剖结构显示情况,并进行统计学分析,以P<0.05为差异有统计学意义。结果随着管电流减低,图像信噪比减低,各组差异有统计学意义(P<0.005),而各组图像对骨性解剖结构评价差异无统计学意义(P>0.05)。结论联合Simplant软件,使用120 k V,35m As,可明显降低放射剂量,对种植部位进行完整、精确的评价。展开更多
The safety of large structures requires adequate foundations, which implies a good knowledge of the geological and geotechnical conditions of the respective ground. In general, that is only possible through engineerin...The safety of large structures requires adequate foundations, which implies a good knowledge of the geological and geotechnical conditions of the respective ground. In general, that is only possible through engineering geological studies which include proper site investigation techniques, adapted to the nature of the ground (rock mass or soil) and to the associated engineering problems. The paper illustrates the studies carried out for the design of the foundations of Ribeiradio 76 m high concrete gravity dam in a difficult rock mass and of Vasco da Gama Bridge, 13 km long, crossing the Tagus River in Lisbon, Portugal, through piles 75 m deep.展开更多
文摘目的评价64排螺旋CT联合Simplant软件使用不同管电流低剂量扫描方案的临床价值。方法选取临床需要种植牙术前评估行64排CT扫描的214例成年患者,其中男性128例,女性86例,随机分为3组,使用Philips Brilliance 64排螺旋CT,管电压固定(120 k V),分别以250 m As,50 m As,35 m As管电流扫描,双盲法测量各组重建图像的噪声,评价图像质量、结合Simplant软件的效果及解剖结构显示情况,并进行统计学分析,以P<0.05为差异有统计学意义。结果随着管电流减低,图像信噪比减低,各组差异有统计学意义(P<0.005),而各组图像对骨性解剖结构评价差异无统计学意义(P>0.05)。结论联合Simplant软件,使用120 k V,35m As,可明显降低放射剂量,对种植部位进行完整、精确的评价。
文摘The safety of large structures requires adequate foundations, which implies a good knowledge of the geological and geotechnical conditions of the respective ground. In general, that is only possible through engineering geological studies which include proper site investigation techniques, adapted to the nature of the ground (rock mass or soil) and to the associated engineering problems. The paper illustrates the studies carried out for the design of the foundations of Ribeiradio 76 m high concrete gravity dam in a difficult rock mass and of Vasco da Gama Bridge, 13 km long, crossing the Tagus River in Lisbon, Portugal, through piles 75 m deep.
