Application of “double low”technique in dual-source CT coronary angiography for low-weight patients / 实用放射学杂志

ABSTRACT

Objective To explore the feasibility of “double low ”(low tube voltage and low contrast agent concentration)imaging technology of dual-source computed tomography (DSCT)in coronary angiography for low-weight patients.Methods 60 patients (BMI≤25 kg/m2 )who underwent coronary CT angiography (CCTA)on DSCT scanner were divided randomly into 2 groupsgroup A was “double low”group (n = 30,tube voltage = 80 kVp,using sinogram affirmed iterative reconstruction technology and 270 mg I/mL concentration of contrast agent);Group B was conventional group (n=30,tube voltage=120 kVp,using filtered back projection technology and 350 mg I/mL concentration of contrast agent).Adaptive cardiosequence prospective ECG-gated technology (CorAdSeq)was applied in both the groups,The collecting phase was 65%-75% RR interval (when heart rate<70 beats per mi-nute)or 40%-50% RR interval (when heart rate≥70 beats per minute).Subjective and objective methods were applied to evaluate the image quality.The image quality and.radiation dose were compared between the “double low”group and the conventional group by using SPSS 1 9.0 software.The differences between measurement data were analyzed by using independent samples t-test.Results The effective dose with size specific dose estimates (EDssde)of group A(1.22±0.31)mGy/cm was significantly lower than that of group B (3.44±0.80)mGy/cm with P <0.001.Contrast-noise ratio,signal-noise ratio and CT value of group A were signifi-cantly higher than those of group B (all P <0.05 ).Conclusion Compared with conventional DSCT coronary angiography,“double low”DSCT coronary scanning proposal for low-weight patients can significantly reduce the radiation dose and the amount of contrast agent,and the image quality can meet the needs of clinical diagnosis.