Evaluation of dose reduction and image quality in chest CT using adaptive statistical iterative reconstruction with the same group of patients
Evaluation of dose reduction and image quality in chest CT using adaptive statistical iterative reconstruction with the same group of patients
复制标题
自适应统计迭代重建同组患者胸部CT剂量减少及图像质量评价
DOI：
10.1259/bjr/66327067
复制
发表时间：
2012-10-01
影响因子：
2.6
通讯作者：
Zhang, X-P
中科院分区：
文献类型：
--
作者：
Qi, L-P;Li, Y.;Zhang, X-P
目的：本研究的目的是比较自适应统计迭代重建（ASIR）和滤波反投影（FBP）混合重建的胸部CT图像的图像质量和辐射剂量与使用传统FBP生成的图像。方法：将胸部CT复查患者交替分配到不同重建技术的两台扫描仪上。研究组包括噪音指数（NI） 11, 30% ASIR (A30), NI 13, 40% ASIR (A40), NI 15, 50% ASIR （A50）和NI 17, 60% ASIR (A60)，每2个月依次改变一次。对照图像采用FBP和ni11获取。所有采集均采用自动剂量调制。采用配对t检验和非参数检验比较差异。结果：使用ASIR检查的放射剂量明显降低（p < 0.001）。A30、A40、A50、A60组的平均剂量减少率分别为27.7%、45.2%、57.1%、71.8%。A30-A50组的图像质量不低于对照检查。A60组图像噪声较大，主观图像质量较对照组差。结论：ASIR能够使用具有自动剂量调制的更高NI。当ASIR为50%，NI为15时，有效辐射剂量减少57%，而不影响图像质量。
Objectives: The objective of this study was to compare the image quality and radiation dose of chest CT images reconstructed with a blend of adaptive statistical iterative reconstruction (ASIR) and filtered back-projection (FBP) with images generated using conventional FBP.Methods: Patients with chest CT re-examinations were alternately assigned to two scanners with different reconstruction techniques. The study groups included noise index (NI) 11 with 30% ASIR (A30), NI 13 with 40% ASIR (A40), NI 15 with 50% ASIR (A50) and NI 17 with 60% ASIR (A60), sequentially changed every 2 months. The control images were obtained using FBP and NI 11. All acquisitions were performed with automatic dose modulation. Paired t-test and non-parameter test were applied to compare the difference.Results: The radiation doses were significantly lower in the examinations that used ASIR (p < 0.001). The mean dose reduction rate was 27.7%, 45.2%, 57.1% and 71.8% for Groups A30, A40, A50 and A60, respectively. The image quality of Groups A30-A50 was not inferior to that of the control examinations. The image noise of Group A60 was greater and subjective image quality was inferior to that of the control.Conclusions: ASIR enabled the use of a higher NI with automatic dose modulation. With 50% ASIR and a NI of 15, the effective radiation dose was reduced by 57%, without compromising image quality.