低管电压CT联合迭代重建技术在眼眶CT检查中的应用

Combined application of low tube voltage and iterative reconstruction for CT imaging of the orbit

目的:探讨低管电压联合迭代重建技术(IR)在眼眶CT检查中的应用价值。方法 :2014年6月—2015年1月于我院行眼眶CT平扫患者90例,随机分为120 k V组(A组)、100 k V组(B组)、80 k V组(C组),每组30例。A组行滤波反投影(FBP)重建,B组和C组行IR重建(idose3)。对各组进行图像质量主观及客观评价,记录各组辐射剂量。对图像质量及辐射剂量进行统计学分析。结果:A、B、C组各组的有效剂量分别为(7.3±0.7)m Sv、(4.5±0.3)m Sv、(2.2±0.2)m Sv,各组间差异有统计学意义。各组图像均满足诊断要求,图像质量评分均高于3分,且两观察者对图像质量评价的一致性好或非常好。低剂量组的图像背景噪声较常规剂量组高,且差异有统计学意义(P<0.05)。结论:低管电压联合IR技术在眼眶CT检查中能明显降低CT辐射剂量同时图像满足诊断要求。

Objective： To investigate the combined application value of low tube voltage and iterative reconstruction（IR） for CT imaging of the orbit. Methods： From June 2014 to January 2015 in our hospital, 90 patients were referred for orbit CT. Patients were randomly assigned into three groups： 120 kV group（group A）, 100 kV group（group B） and 80 kV group（group C）, with 30 cases in each group. Group A underwent filtered back projection（FBP） reconstruction while group B and C underwent IR reconstruction. Subjective and objective evaluations were performed on image quality and radiation dose was recorded for each group, which were statistically analyzed. Results： The average effective dose of group A, B and C were （7.3±0.7） mSv, （4.5±0.3） mSv and （2.2±0.2） mSv respectively. There were significant difference among groups. The images of the three groups all met the diagnostic requirement. All image quality scores were higher than 3 points. The consistency of the two observers in evaluating image quality was either good or very good. The image background noise of low-dose group was higher than that of standard dose group, and the difference was statistically significant （P〈0.05）. Conclusion： Low tube voltage combined with IR algorithm in orbit CT examination can significantly reduce radiation dose, and the image quality can meet the diag- nostic requirement.