Smarda Magdalini, Efstathopoulos Efstathios, Mazioti Argyro, Kordolaimi Sofia, Ploussi Agapi, Priftis Konstantinos, Kelekis Nikolaos, Alexopoulou Efthymia
Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece.
Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece.
Can Assoc Radiol J. 2016 Aug;67(3):218-24. doi: 10.1016/j.carj.2015.10.003. Epub 2016 Apr 15.
High radiosensitivity of children undergoing repetitive computed tomography examinations necessitates the use of iterative reconstruction algorithms in order to achieve a significant radiation dose reduction. The goal of this study is to compare the iDose iterative reconstruction algorithm with filtered backprojection in terms of radiation exposure and image quality in 33 chest high-resolution computed tomography examinations performed in young children with chronic bronchitis.
Fourteen patients were scanned using the filtered backprojection protocol while 19 patients using the iDose protocol and reduced milliampere-seconds, both on a 64-detector row computed tomography scanner. The iDose group images were reconstructed with different iDose levels (2, 4, and 6). Radiation exposure quantities were estimated, while subjective and objective image qualities were evaluated. Unpaired t tests were used for data statistical analysis.
The iDose application allowed significant effective dose reduction (about 80%). Subjective image quality evaluation showed satisfactory results even with iDose level 2, whereas it approached excellent image with iDose level 6. Subjective image noise was comparable between the 2 groups with the use of iDose level 4, while objective noise was comparable between filtered backprojection and iterative reconstruction level 6 images.
The iDose algorithm use in pediatric chest high-resolution computed tomography reduces radiation exposure without compromising image quality. Further evaluation with iterative reconstruction algorithms is needed in order to establish high-resolution computed tomography as the gold standard low-dose method for children suffering from chronic lung diseases.
接受重复计算机断层扫描检查的儿童具有较高的放射敏感性，因此需要使用迭代重建算法以显著降低辐射剂量。本研究的目的是在对患有慢性支气管炎的幼儿进行的33次胸部高分辨率计算机断层扫描检查中，比较iDose迭代重建算法与滤波反投影在辐射暴露和图像质量方面的差异。
在64排探测器计算机断层扫描仪上，14例患者采用滤波反投影协议进行扫描，19例患者采用iDose协议并降低毫安秒进行扫描。iDose组图像用不同的iDose水平（2、4和6）进行重建。估计辐射暴露量，同时评估主观和客观图像质量。采用非配对t检验进行数据统计分析。
应用iDose可显著降低有效剂量（约80%）。主观图像质量评估显示，即使是iDose水平2，结果也令人满意，而iDose水平为6时接近优秀图像。使用iDose水平4时，两组之间的主观图像噪声相当，而滤波反投影和迭代重建水平6图像之间的客观噪声相当。
在儿科胸部高分辨率计算机断层扫描中使用iDose算法可降低辐射暴露，且不影响图像质量。需要对迭代重建算法进行进一步评估，以便将高分辨率计算机断层扫描确立为患有慢性肺部疾病儿童的金标准低剂量方法。
