低kV扫描技术在肾脏肿瘤CT检查中的应用探讨

Application study of dual-energy scan in the detection of the kidney tumors

目的利用双源CT对肾肿瘤患者增强扫描动脉期进行双能量扫描,对不同k V(千伏,kilovoltage)的图像质量进行比较、分析,研究不同管电压对肾肿瘤动脉期扫描图像质量的影响,从而探讨肾脏肿瘤的低管电压CT扫描的可行性。方法采用Siemens SOMATOM Definition FLASH双源CT扫描仪。随机选取肾肿瘤患者40例作为研究对象。所有病例均行增强扫描,动脉期均采用双能量扫描。高、低管电压分别采用100 k V和140 k V。对高、低管电压图像及融合图像的图像质量分别进行评价,两名医生采用5分法对图像质量进行评价。采用威尔科克森(Wilcoxon)符号秩和检验进行统计学分析。结果 100 k V、120 k V与140 k V三组图像的质量评分分别为46、41和126,100 k V与120 k V的图像质量相比,二者的图像质量无明显差异;100k V与120 k V的图像质量均优于140 k V的图像质量,之间差异具有统计学意义(P<0.05)。结论肾脏肿瘤的CT增强扫描采用100 k V的低管电压是可行的,能够获得满足临床诊断需要的优质图像。

Objective The dual-energy scans in arterial phase of enhancement CT were performed in renal tumors patients.The purpose of this study was to investigate the the feasibility of the low kilovoltage CT scan by comparing the effects of different tube voltages on the images quality. Methods 40 cases of patients with renal tumors were randomly selected to be research object. All of the patients were examined by the dual-energy scans in arterial phase of enhancement CT（ Siemens SOMATOM Definition FLASH）,and the higher and the low tube voltage was used with 140 kV and 100 kV respectively. Each patient could obtain three sets of images：the lower tube voltage（ 100 kV） images,the higher tube voltage images（ 140 kV） and fused images（ 120 kV）. Image quality of three sets of images was compared and evaluated statistically by two blinded experienced CT diagnosis doctors according to the method of five points in the case of unknowning CT scan conditions. The scores of the three groups of images were compared respectively with the statistical method of Wilcoxon Signed Ranks Test, the differences between them were statistically significance when P〈0. 05.Results The image quality scores of 100 kV,120 kV and140 kV were 46,41and126. The image quality of 100 kV and 120 kV are better than that of 140 kV,the image quality has statistically significant difference（ P〈0. 05）,and the image quality of 100 kV and 120 kV was no statistically significant difference（ P〈0. 05）. Conclusions Kidney enhanced CT scanning using lower tube voltage of 100 kV is feasible. The excellent image quality can meet the need of clinical diagnosis of renal tumors patients.