Lungscreening迭代重建技术在低剂量CT胸部体检中的应用价值

Application of Lungscreening Iterative Reconstruction Technique in Low-dose Chest CT

目的:探讨Lungscreening迭代重建技术在低剂量CT胸部体检中的应用价值。方法:选取CT体检者200例作为研究对象,所有入选病例体质量指数(BMI)控制在18-24kg/m2范围内,分别以低剂量扫描和常规剂量扫描,获得低剂量组和常规剂量组各100份CT图像资料,对两组图像的曝光量、容积CT剂量指数和剂量长度乘积进行比较,图像质量由高年资医师与技师各一名观察并评级,对其结果进行统计学处理。结果:低剂量组的曝光量值(38.91±8.27)mAs显著低于常规剂量组(148.30±0.27)mAs(t=132.13,P<0.01)。低剂量组的容积剂量指数(2.63±0.56)mGy亦显著低于常规剂量组(10.01±0.01)mGy(r=132.16,P<0.01),同样,低剂量组剂量长度乘积值(82.26±18.10)mGy•cm显著低于常规剂量组(310.28±33.85)mGy•cm(r=59.40,P<0.01),两组图像质量差异无统计学意义(χ2=1.71,P>0.05)。结论:胸部低剂量CT扫描结合迭代重建技术,可在满足诊断要求的前提下,大幅度减少辐射剂量,在胸部CT体检应用中具有重要的指导意义。

Purpose:To explore the application of Lungscreening iterative reconstruction technique in low-dose chest CT physical examination.Methods:Two hundred cases with chest CT examination were divided into lowdose group and conventional dose group.Body mass index of all 200 subjects were controlled between 18 and 24kg/m2.The difference of radiant exposure value,CT dose index volumes(CTDIVOL)and dose length product(DLP)between the two scan modes were compared.The imaging quality of the two modes was also evaluated in term of the subjective grading conducted by a radiologist and a technician.Results:The radiant exposure value of the low-dose group was(3&91±8.27)mAs,which was significantly lower than that of the conventional dose group(148.30±0.27)mAs(t=132.13,P<0.01),the CTDIVOL value of low-dose group was(2.63±0.56)mGy,which was also significantly lower than that of the conventional dose group(10.01±0.01)mGy(r=132.16,P<0.01).Similarly,the DLP value of lowdose group was(82.26±18.10)mGycm,which was also significantly lower than that of the conventional dose group(310.28±33.85)mGycm(t=59.40,P<0.01).The imaging quality of the two groups were analyzed by Chi-square Test(χ2=1.71,P>0.05).Conclusion:The radiation dose can be effectively reduced without affecting diagnosis effect by low dose chest CT scan combined with Lungscreening iterative reconstruction technique,which has great significance in chest CT physical examination.