目的:研究64排螺旋X射线计算机体层扫描(CT)机低管电压联合高管电流技术用于肾癌术前诊断的价值。方法:选取医院收治的156例肾癌患者,采用随机数表法将其分为观察组和对照组,每组78例,两组均行全腹部多期增强CT扫描,观察组扫描参数中管...目的:研究64排螺旋X射线计算机体层扫描(CT)机低管电压联合高管电流技术用于肾癌术前诊断的价值。方法:选取医院收治的156例肾癌患者,采用随机数表法将其分为观察组和对照组,每组78例,两组均行全腹部多期增强CT扫描,观察组扫描参数中管电压为90 k V,管电流为550 m A;对照组管电压为120 k V,自动选择管电流。两组对比剂均为碘普罗胺,注射速度均为3.0 ml/s,对比剂剂量分别为1.0 ml/kg、1.5 ml/kg。采集两组皮髓质期(CMP)图像和实质期(NP)图像,记录并计算CMP图像的肿瘤感兴趣区域(ROI)、肾实质ROI、对比度噪声比(CNR)和信噪比(SNR)以及NP图像的肿瘤ROI、肾实质ROI、肾静脉ROI和SNR。采用4分法对两组采集的CMP、NP图像进行评分;对比两组CMP、NP的剂量长度乘积(DLP)和有效剂量(ED)的辐射剂量和总辐射剂量。结果:两组CMP和NP图像质量及主观评分差异均无统计学意义(P>0.05)。观察组CMP、NP的DLP和ED的辐射剂量以及总辐射剂量均低于对照组,其差异有统计学意义(t_(CMP)=5.086,t=9.833;t_(NP)=6.483,t=10.802;t_(总辐射剂量)=10.984;P<0.05)。结论:64排螺旋CT机低管电压联合高管电流技术进行肾癌诊断可清晰显示肾癌患者病灶,同时可降低对比剂使用剂量和辐射剂量,有利于减轻辐射对肾功能的损害。展开更多
This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electroh...This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electrohydrodynamic flow of a fluid in an ion drag configuration in a circular cylindrical conduit. The accuracy of the present solution is found to be in excellent agreement with the previously published solution. The authors use an averaged residual error to find the optimal convergence-control parameters. Comparisons are made between SHAM generated results, results from literature and Matlab ode45 generated results, and good agreement is observed.展开更多
文摘目的:研究64排螺旋X射线计算机体层扫描(CT)机低管电压联合高管电流技术用于肾癌术前诊断的价值。方法:选取医院收治的156例肾癌患者,采用随机数表法将其分为观察组和对照组,每组78例,两组均行全腹部多期增强CT扫描,观察组扫描参数中管电压为90 k V,管电流为550 m A;对照组管电压为120 k V,自动选择管电流。两组对比剂均为碘普罗胺,注射速度均为3.0 ml/s,对比剂剂量分别为1.0 ml/kg、1.5 ml/kg。采集两组皮髓质期(CMP)图像和实质期(NP)图像,记录并计算CMP图像的肿瘤感兴趣区域(ROI)、肾实质ROI、对比度噪声比(CNR)和信噪比(SNR)以及NP图像的肿瘤ROI、肾实质ROI、肾静脉ROI和SNR。采用4分法对两组采集的CMP、NP图像进行评分;对比两组CMP、NP的剂量长度乘积(DLP)和有效剂量(ED)的辐射剂量和总辐射剂量。结果:两组CMP和NP图像质量及主观评分差异均无统计学意义(P>0.05)。观察组CMP、NP的DLP和ED的辐射剂量以及总辐射剂量均低于对照组,其差异有统计学意义(t_(CMP)=5.086,t=9.833;t_(NP)=6.483,t=10.802;t_(总辐射剂量)=10.984;P<0.05)。结论:64排螺旋CT机低管电压联合高管电流技术进行肾癌诊断可清晰显示肾癌患者病灶,同时可降低对比剂使用剂量和辐射剂量,有利于减轻辐射对肾功能的损害。
文摘This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electrohydrodynamic flow of a fluid in an ion drag configuration in a circular cylindrical conduit. The accuracy of the present solution is found to be in excellent agreement with the previously published solution. The authors use an averaged residual error to find the optimal convergence-control parameters. Comparisons are made between SHAM generated results, results from literature and Matlab ode45 generated results, and good agreement is observed.
