| 迭代算法在泌尿系结石CT低剂量扫描中的应用价值及最优方案探讨 |
| 投稿时间：2015-11-16 修订日期：2015-11-30 点此下载全文 |
| 引用本文：李丽超,宫凤玲,周立娟,马骊骅,马春梅.迭代算法在泌尿系结石CT低剂量扫描中的应用价值及最优方案探讨[J].医学研究杂志,2016,45(6):164-167 |
| DOI：
10.11969/j.issn.1673-548X.2016.06.042 |
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| 中文摘要:目的 评价迭代算法在泌尿系结石CT低剂量扫描中的应用价值及最优方案探讨。方法 搜集78例泌尿系结石患者，首次检查均应用常规剂量扫描（120kV/400mAs），采用滤波反投影算法（filtered back projection，FBP）薄层重建，保守治疗后结石未排出，复查CT应用低剂量扫描（120kV/200mAs），行6级迭代算法薄层重建。由两位放射医师采用双盲法读片并对图像质量做主观评分，记录CT容积剂量指数（CTDIvol）、剂量长度乘积（DLP），计算有效剂量（ED）；测量图像的客观噪声值，计算信噪比，测量结石CT值及最大长径，记录结石检出数。结果 常规组CTDIvol为22.42±1.03mGy，DLP为870.46±450.69mGy·cm，ED为17.52±2.85mSv，低剂量组CTDIvol为11.26±0.53mGy，DLP为435.83±225.32mGy·cm，ED为8.77±1.43mSv；低剂量组联合迭代算法重建的iDose1～6图像结石检出数、结石CT值及直径与常规组比较差异无统计学意义（P>0.05）；低剂量迭代算法重建的iDose4图像噪声、信噪比及iDose4-6图像质量主观评分与常规剂量比较差异无统计学意义（P>0.05）；低剂量组联合迭代算法重建的iDose1～3和iDose5～6图像噪声、信噪比及iDose1～3图像质量主观评分与常规组比较差异有统计学意义（P<0.05）。结论 CT低剂量扫描联合迭代算法诊断泌尿系结石有可行性，可在不影响图像质量的前提下明显降低了辐射剂量。迭代算法重建中iDose4在泌尿系结石的CT低剂量扫描中为最优临界水平。 |
| 中文关键词:CT 泌尿系结石 低剂量 迭代算法 |
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| Discussion on Optimized Plans and the Application Values of Iterative Algorithm in CT Low-Dose Scan of Urinary Calculi |
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| Abstract:Objective To comment on the application values of iterative algorithm in CT low-dose scan of urinary calculi and to discuss the optimized plans. Methods Totally 78 cases of urinary calculi patients were collected. For the first testing, the stand-dose scan (120kV/400mAs) was applied. The filtered back projection (FBP) algorithm was employed for thin-slice reconstruction. The calculi could not be removed after the conservative treatment. During the re-examination, CT low-dose scan (120kV/200mAs) was utilized, and 6-level iterative algorithm was conducted for thin-slice reconstruction. Two radiologists used double blind method to read the photos and did subjective scoring for the quality of the photos. The CTDIvol and DLP were recorded and the ED was calculated. The objective noise level of the photos was measured and the signal-to-noise ratio was computed. The CT value and maximum length of the calculi were measured, and the number of detected calculi was recorded. Results in the contrast group. CTDIvol:22.42±1.03mGy,DLP:870.46±450.69mGy·cm,ED:17.52±2.85mSv while in low-dose group, CTDIvol:11.26±0.53mGy,DLP:435.83±225.32mGy·cm,ED:8.77±1.43mSv. Differences between the number, CT value and size of detected calculi by iDosel-6 image re-constructed by the low-dose group combined with iterative algorithm and those of the contrast group have no statistic significance (P>0.05); Differences between noise level and signal-to-noise ratio of iDose 4 image reconstructed by low-dose iterative algorithm and the subjective scoring for the quality of iDose4-6 images and those in the contrast group have no statistic significance(P>0.05). Differences between the noise level and signal-to-noise ratio of iDose1-3 and iDosel5-6 images re-constructed by the low-dose group combined with the iterative algorithm and the subjective scoring for the quality of iDose1-3 and those in the contrast group have statistic significance(P<0.05). Conclusion To use CT low-dose scan in combination with iterative algorithm for the diagnosis of urinary calculi is practicable and feasible, which could obviously reduce the radiation dose without influencing the quality of photos. During the re-constructing of iterative algorithm, iDose4 is in the optimized critical level for the CT low-dose scan of urinary calculi. |
| keywords:Computed tomography Ureteral calculi Low dose Iterative algorithm |
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