Low-dose MSCT pulmonary angiography: low kVp with individual-adapted low tube current / 中华放射医学与防护杂志

ABSTRACT

Objective To assess the feasibility of low-dose MDCT pulmonary angiography (MDCTPA) by using low kVp combined with individual-adapted low tube current protocol and noise reduction filter algorithms.Methods Fifty-six consecutively patients with MDCTPA were enrolled in the study.The patients were randomly divided into group A (120 kVp,100 mAs) and group B (100 kVp,individual-adapted tube current about 1.0 mAs/kg).Two series of images were reconstructed in group BB1 with standard filter algorithms (FC13,B1) and B2 with noise reduction filter algorithms (FC11,B2).The image noise,quality and radiation dose in two groups were compared.Results The CTDIvol,DLP and E of group B were 5.1 mGy,83.3 mGy· cm and 1.4 mSv respectively,which were reduced by 64.3％,66.4％ and 66.7％,respectively (F =32.57,12.32,11.98,P ＜ 0.05) when compared with those in group A.Compared with group A,the image noise in B1 was increased by 118.2％ (t =10.05 P ＜0.05),the central and peripheral SNR and CNR and scores were increased by 51.5％,46.6％,50.8％,45.3％and 20.4％,respectively(t =7.20,6.30,6.58,5.54,8.35,P ＜ 0.05).Compared with B1,the image noise in B2 was reduced by 32.5％ (t =6.12,P ＜0.05),the central and peripheral SNR and CNR and scores were increased by 46.2％,46.2％,45.9％,46.9％ and 18.4％ (t =3.19,3.55,2.95,3.37,5.42,P ＜0.05).Compared with group A,the image noise in B2 group was increased by 47.3％ (t =4.03,P ＜0.05),the central and peripheral SNR and CNR and scores were reduced by 29.1％,21.8％,28.2％,19.6％ and 8.2％(t =4.06,2.82,3.68,2.22,3.02,P＜0.05).Conclusions Keeping effective diagnostic image quality,the protocol with low kVp and individual-adapted low tube current for low-dose MDCT pulmonary angiography would be effective and feasible,and the radiation dose would be significantly reduced.