肥胖患者80 kV与120 kV不同重建算法CTPA图像质量分析

目的 分析肥胖患者高、低管电压迭代重建(IR)算法与滤波反投影(FBP)算法的CT肺动脉造影(CTPA)图像质量及辐射剂量,探讨低管电压IR算法在肥胖患者CTPA中的可行性.方法 将临床疑似肺栓塞需行CTPA检查的肥胖患者随机分为80 kV或120 kV组,均采用IR及FBP方式对图像进行后处理.测量肺动脉主干、右肺上叶动脉及右肺下叶后基底段动脉的CT值,计算肺动脉平均CT值,采用独立样本t检验分析.结果 高、低管电压组IR亚组的肺动脉CT值与FBP亚组相比,差异无显著性(P>0.05),噪声、信噪比(SNR)、对比噪声比(CNR)的差异有统计学意义(P<0.05).80 kV组的肺动脉CT值、噪声、SNR、CNR均明显高于120 kV组,且差异有统计学意义(P<0.05),而辐射剂量均明显低于120 kV组,差异亦有统计学意义(P=0.000).结论 与120 kV联合FBP算法相比,80 kV联合IR算法的CTPA图像质量明显提高,且患者所受辐射剂量明显降低,可用于肥胖患者的CTPA.

CTPA image quality analysis of 80 kV and 120 kV in different reconstruction algorithms for obese patients

Objective To analyze the CT pulmonary angiography(CTPA) image quality and radiation dose of obesity patients with high and low tube voltage iterative reconstruction(IR) and the filtered back projection(FBP) reconstruct algorithm,and to explore the feasibility of low tube voltage IR algorithms in CTPA of obese patients.Methods Obese patients with suspected pulmonary embolism were randomly assigned into 80 kV or 120 kV group, and the images were treated with IR and FBP reconstructions.CT value of the basal segment of the right pulmonary artery, right upper lobe and main pulmonary artery were measured, and the average CT value of the pulmonary artery was further calculated, and the independent sample t test analysis was used.Results Comparing the CT value of the IR and FBP subgroup of two tube voltage groups, the differences were not significant (P>0.05), the differences of noise, signal noise ratio(SNR) and contrast noise ratio (CNR) were statistically significant (P<0.05), respectively.The CT value,noise,SNR and CNR of 80 kV group were significantly higher than those of the 120 kV group, and the differences were statistically significant (P<0.05), while the radiation dose were significantly lower than those of 120 kV group (P=0.000).Conclusion The CTPA image quality of 80 kV IR algorithm is significantly improved compared with the 120 kV FBP algorithm, and the radiation dose is significantly reduced, which could be used for CT pulmonary angiography in obese patients.