【摘要】 目的探讨低剂量CT扫描结合i Dose4技术在肾盂及输尿管病变诊断中的临床应用价值。方法对150例经超声检查为肾盂及输尿管积水患者,随机分为5组(每组30例),分别行标准剂量组、低剂量1~4组CT检查。标准剂量组扫描采用管电压120k V,平均m As为100m As,低剂量1~4组管电压仍为120k V,平均m As分别为40m As、35m As、30m As、25m As,其他扫描条件均与标准剂量组相同。记录每位患者的身高、体重和每次扫描的CTDIvol、DLP和有效剂量ED。所有图像均通过i Dose4进行Level1-Level 6及FBP法重建并测量所有图像的噪声,由两名医师对图像质量进行主观评分,两名医师对图像的主观评分的一致性评价使用Kappa检验。结果低剂量1~4组与标准剂量组在身体质量指数(BMI)基本一致,相比均为P>0.05,无统计学意义。低剂量1~4组分别与标准剂量组在发现结石(包括例数、数量、大小范围)相比差异均无统计学意义(P>0.05)。低剂量1~4组的辐射剂量分别减少了60%、68%、72%、76%,与标准剂量组相比差异有统计学意义(P<0.0001)。i Dose4软件的Level 6重建后的图像噪声最小,主观评分最高,差异有统计学意义(P<0.0001)。结论 20kg/m2<BMI<30kg/m2的患者:采用低剂量CT扫描结合i Dose4技术,当平均m As≥25时能满足结石的诊断要求;当平均m As≥35~40时能满足所有病变的诊断要求。i Dose4软件的Level 6重建后的图像对肾盂及输尿管的显示效果最好,可满足诊断要求。更多还原

【Abstract】 Objective To assess the value on clinical application in low dose CT scanning combined with the technology of i Dose4 in patients of renal pelvis and urethral lesions. Methods 150 cases with renal pelvis and ureter water by ultrasound examination underwent CT examination. They were randomly divided into 5 groups( 30 cases in each group) for regular dose and low dose groups( group1 ~ 4) scans. The group of regular dose was performed with the following parameters: tube voltage of 120 k V,effective tube current of 100 m As. Group 1 ~ 4 were performed with following parameters: tube voltage of 120 k V,effective tube current of 40 m As,35 m As,30 m As,25 m As,respectively. Other scanning requirements were as same as the group of regular dose. We recorded each patient’s height and weight. Radiation exposure for each patient was calculated using an established formula of dose length product and scan length. The effective total dose was measured in milligray( m Gy). After the images were acquired,a new set of coronal and Level1 ~ Level6 images by the technology of i Dose4 for reconstruction purposes were created. All the noises of the image were recorded. Two radiologists blinded to the scan conditions independently reviewed all data sets for image quality,noise,and calculi( number,size,location). Inter-reader agreement between the two radiologists for all groups was performed using Conhen kappa statistics. Statistical analysis was performed using statistical software SAS,version9. 13. Statistical significance for all tests was set at P < 0. 05. Results No statistical significance differences were seen between the group of regular dose and low dose of group 1 ~ 4 in the BMI( P > 0. 05). No statistical significance differences were seen between the group of regular dose and group 1 ~ 4 in calculus( including the number of cases,the quantities of stones,size range)( P > 0. 05). The radiation dose of group 1 ~ 4 reduced by 60%,68%,72% and 76% respectively,the difference was statistically significant compared with the group of regular dose( P < 0. 0001). The noises of the images from the reconstruction of i Dose4-level6 were minimum,the subjective scores were the highest( P < 0. 0001). Conclusion In patients with a 20 kg / m2< BMI < 30 kg / m2,low dose CT( 120 k V,25 m As) combined with the technology of i Dose4 can meet the demand of the diagnosis of renal pelvis and ureter stones,and low dose CT( 120 k V,35 ~ 40 m As) combined with the technology of i Dose4 was 100%sensitive for detecting renal pelvis and urethral lesions. It shows that the images from the reconstruction of i Dose4-level6 can meet the best diagnostic requirements for renal pelvis and ureter.更多还原