输尿管结石低剂量CT扫描中不同iDose等级、不同层厚重建图像的质量比较

发布时间：2018-07-06 11:40

本文选题：CT检查 + 输尿管结石　；参考：《山东医药》2016年11期

【摘要】：目的比较输尿管结石低剂量CT扫描中不同i Dose等级、不同层厚重建图像的质量。方法 78例输尿管结石患者,经保守治疗后结石未排出,首次检查采用常规剂量(120 k V/400 m As)CT扫描并用滤波反投影算法(FBP)1 mm薄层重建(常规组),复查采用低剂量(120 k V/200 m As)CT扫描并行6级迭代算法1 mm薄层重建(低剂量组)。记录CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP),计算有效剂量(ED);首先通过图像质量主观评分、图像的客观噪声值、信噪比及结石检出数评价出1 mm最合理的i Dose等级,再对最优i Dose等级行1.5 mm及2 mm重建,评价出最优i Dose重建层厚。结果低剂量组、常规组CTDIvol分别为(11.26±0.53)、(22.42±1.03)m Gy,DLP分别为(584.68±25.47)、(1 166.38±52.78)m Gy*cm,ED分别为(8.77±1.43)、(17.52±2.85)m Sv,两组比较,P均0.05。低剂量迭代算法重建的1 mm i Dose4等级图像噪声、信噪比及i Dose4~6等级图像质量主观评分、结石检出数分别与常规剂量组比较,P均0.05。1.5、2 mm与1 mm i Dose4重建图像噪声比较,P均0.05;2 mm与1 mm i Dose4重建图像信噪比比较,P0.05;1、1.5、2 mm i Dose4重建结石检出数分别为91、91、89枚,三者图像质量主观评分比较差异无统计学意义。结论输尿管结石低剂量CT扫描的图像质量受迭代算法i Dose等级及重建层厚的影响,i Dose4是最优临界水平,此水平1.5 mm层厚重建为最合理方案。
[Abstract]:Objective to compare the quality of different I lose grade and different slice thickness in low dose CT scan of ureteral calculi. Methods 78 patients with ureteral calculi were treated conservatively. The conventional dose (120kV / 400 m As) CT scan) and filter backprojection (FBP) 1 mm thin layer reconstruction (conventional group) were used for the first time, and low dose (120kV / 200 m As) CT scan and 6 stage iterative algorithm 1 mm thin layer reconstruction (low dose group). Ct volume dose index (CTDIvol), dose length product (DLP) and effective dose (Ed) were recorded. Then 1.5 mm and 2 mm reconstruction was performed on the optimal I Dose grade, and the optimal thickness of I Dose reconstruction layer was evaluated. Results CTDIvol was (11.26 卤0.53), (22.42 卤1.03) m), (in the low dose group and (584.68 卤25.47), (1 166.38 卤52.78) m), (in the conventional group, respectively. The difference between the two groups was (8.77 卤1.43), (17.52 卤2.85) mSv. The image noise, signal-to-noise ratio (SNR) and image quality of 1mm I Dose4 grade reconstructed by low dose iterative algorithm were evaluated. Compared with the conventional dose group, the number of stones detected was 0.05.1.5mm and 1 mm I Dose4 respectively. There was no significant difference in subjective score of image quality among the three groups. Conclusion the image quality of low-dose CT scan of ureteral calculi is affected by the iterative algorithm I lose grade and reconstruction slice thickness. I Dose4 is the optimal critical level, and this level of 1.5 mm slice thickness reconstruction is the most reasonable scheme.
【作者单位】：唐山市工人医院分院;华北理工大学附属医院;
【分类号】：R693.4

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