Abstract：Objective To investigate the optimal ASIR (Adaptive Statistical Iterative Reconstruction)
weight and low-dose scanning parameters in gem energy spectrum CT scanning of paranasal sinuses
in children. Methods Gem energy spectrum CT was applied to perform paranasal scans in 20 cases of
children. The scanning conditions were 100 kV, 50 mA, image reconstruction by using 10% to 100%
weight of the adaptive iterative reconstruction technique under the present scanning conditions as well
as the noise value (image standard deviation SD value) and CNR (Contrast-to-Noise Ratio) evaluation.
Three radiologists were invited to make a subjective evaluation (ranging from 5 to 0 score) of the image
and select the optimum image quality weight. And on the basis of optimum image quality weight,
100 cases of children with paranasal sinuses were screened and divided into five groups. 20 cases
in Conventional Dose Group (Group A) were scanned under the conditions of (120 kV, 90 mA) and
underwent image reconstruction by using FBP (Filtered Back Projection) algorithm as Control Group; 20
patients in four Low-Dose Groups (namely B1, B2, B3, B4) were scanned under the conditions of (100
kV, 85 mA; 100 kV, 50 mA; 80 kV,85 mA; 80 kV,50 mA) scan and underwent image reconstruction by
using original projection data and ASIR algorithm; the rest conditions remained unchanged. The CT dose
index volume (CTDIvol) and dose length product (DLP) of 5 groups were recorded and radiation dose,
image quality, image noise and CNR of five groups were compared and statistically analyzed. Results
The optimal ASIR weight was 60% under scanning conditions of 100 kV, 50 mA. Radiation dose of Low-
Dose Group by using FBP at 60% ASIR was significantly lower than that of Conventional Dose Group;
compared with Group A, CTDIvol and DLP of Group B1, B2, B3 and B4 decreased by 38.92%, 63.81%,
66.01%, 80.04% and 39.78%, 64.83% ,66.25%, 80.23%; there was no significant difference between
the image quality ratings of compared with Group B1, B2, B3 and Group A (P>0.05), all of which metthe requirements of clinical diagnosis. Compared with Group A (4.57±0.22), the image quality rating
of Group B4 (4.34±0.64) was significantly lower with significantly increased noise, which could not
meet the clinical diagnostic requirements. Conclusion For children with paranasal gems scanned by
energy spectra CT, the optimal adaptive statistical iterative reconstruction weight was 60% and the most
appropriate low dose parameters were B3 (80 kV, 85 mA).
囤荣耀，相爱华，杨蕾，邓昆，
杨瑞山. 儿童副鼻窦CT自适应性统计迭代重建权重和低剂量扫描条件的优化[J]. 中国医疗设备, 2016, 31(11): 62-65.
DUN Rong-Yao, XIANG Ai-Hua,
YANG Lei, DENG Kun,
YANG Rui-Shan. Optimization of Children Paranasal Sinus CT Adaptive Statistical
Iterative Reconstruction Weights and Low-Dose Scanning Conditions. China Medical Devices, 2016, 31(11): 62-65.
