Feasibility study of low tube voltage technique and low concentration of contrast in CT pulmonary angiography by filtered back projection reconstruction / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the feasibility of CT pulmonary angiography (CTPA) with 80 kVp and contrast agent of iodixanol (270 mg I/ml) by filtered back projection(FBP) reconstruction.Methods In total,52 patients who underwent CTPA were randomly divided into two equally-sized groups,control group and experimental group.The volume computed tomography dose index (CTDIvol) and dose-length product (DLP)were recorded,and the weighted computed tomography dose index (CTDIw) and effective dose (E) were calculated.The image quality was visually evaluated and measured,and statistical analyses were performed on the image quality and the radiation dose.Results The sex,age,height,weight and body mass index (BMI) had no statistical difference between two groups (P ＞ 0.05).The average iodine dosage decreased by 22.9％ in the experimental group compared with the control group.Compared with the control group,the CTDIvol,DLP,CTDIw and E decreased by 73.5％,75.1％,73.5％ and 75.8％,respectively.The differences were statistically significant (t =＜0.001,30.5,＜ 0.001,-28.7,P ＜ 0.05).The image quality of the two groups met the requirement of diagnosis and there were no significant statistic differences between visually evaluating and objectively measuring the image quality (P ＞ 0.05).Conclusions Using 80 kVp and iodixanol for CTPA,FBP reconstruction image quality can meet diagnostic requirements.At the same time the radiation dose,the contrast agent dose and the X-ray tube wastage are reduced respectively.