超低管电压(70kVp)联合迭代重建在儿童副鼻窦检查中的应用

Application of 70kVp tube voltage combined with SAFIRE in low-dose CT of pediatric paranasal sinus

目的探讨双源CT超低管电压、超低管电流联合迭代重建技术在儿童副鼻窦检查中的可行性。方法选取80例临床怀疑副鼻窦炎的患儿随机分成对照组(A)、实验组(B)两组,对照组(A)40例采用内部低剂量扫描方案:管电压80 kV,管电流40 mAs,所得数据用滤波方向投影算法(FBP)重建;实验组(B)40例采用超低剂量扫描方案:管电压70 kV,管电流以40 mAs为基准的自动补偿扫描,所得数据用迭代算法(SAFIRE)重建。分别比较两种不同扫描方式的主客观图像质量及辐射剂量,并进行统计学分析。结果实验组(B)的背景噪声明显高于对照组(A)(P<0.001);实验组(B)的软组织CT值、软硬组织SNR均明显低于对照组(A)(P<0.001);两组的硬组织CT值及主观图像质量评分差异无统计学意义(P>0.05)。实验组(B)CTDIvol(mGy)、DLP(mGy·cm)、ED(mSv)较对照组(A)分别降低了91.67%、88.50%、87.18%(P<0.001)。结论利用超低管电压(70 kVp)、超低管电流(实际平均电流量12.2 mAs)联合迭代重建技术获得的CT图像可满足儿童副鼻窦炎患者的影像诊断要求,且明显降低辐射剂量。

Objective To investigate the feasibility of dual-source computed tomography(CT)using ultra-low tube voltage(70 kVp),ultra-low tube current combined with SAFIRE in pediatric paranasal sinus.Methods A total of 80 patients were randomly divided into groups A and B,who were clinically suspected paranasal sinusitis.40 patients in control group(A)were scanned using the in-house low-dose protocol with 80 kVp tube voltage,40 mAs tube current,and filtered back projection(FBP)algorithm.The ultra-low-dose protocol was done in another 40 patients in experimental group(B)with 70 kVp tube voltage,40 mAs tube current simultaneously open CARE Dose 4D,and sinogram affirmed iterative reconstruction(SAFIRE)algorithm.The image quality and radiation dose of the two scanning patterns were compared and analyzed statistically.Results The background noises in the experimental group(B)were significantly higher than those in the control group(A)(P<0.001).The soft-tissue CT value,SNR and bone-tissue SNR in the experimental group(B)were significantly lower than those in the control group(A)(P<0.001).There was no statistically significant difference in the bone-tissue CT value and subjective image quality between the two examination protocols(P>0.05).Compared with control group(A),CTDIvol(mGy),DLP(mGy·cm),ED(mSv)in experimental group(B)decreased by 91.67%,88.50%and 87.18%,respectively(P<0.001).Conclusion Ultra-low tube voltage(70 kVp),ultra-low tube current combined with SAFIRE agent in pediatric paranasal sinus can meet diagnostic image quality,meanwhile,reduce radiation dose significantly.