Application of"double low"dual source CT coronary angiography in patients with high BMI / 实用放射学杂志

ABSTRACT

Objective To explore the feasibility of reducing the tube voltage to 80 kV,while ensuring the CT image quality for the diagnosis when the patients with high BMI (26 kg/m2≤BMI≤30 kg/m2)undergo coronary CTA examination,using low concentration isotonic contrast medium (270 mg I/mL)and iterative reconstruction techniques (SAFIRE-3).Methods Sixty patients with high BMI who underwent coronary CTA were randomly divided into group A and group B.Group A was set as"double low"group (n=30,tube voltage=80 kV),using SAFIRE-3 technology and 270 mg I/mL contrast agent.Group B was set as conventional group (n=30,tube voltage=120 kV),using filtered back projection (FBP)technology and 350 mg I/mL contrast agent.Adaptive cardio-sequence prospective ECG-gated technology (CorAdSeq)was applied in both groups,and the collecting phase was 65%-75% R-R interval (heart rate <75 beats per minute)or 40%-50% R-R interval(heart rate ≥75 beats per minute).Subjective and objective assessment methods were applied to evaluate the quality of images.The image quality and radiation dose of"double low"group was analyzed with conventional group as the control group.SPSS 1 9.0 software was applied for statistical analysis.The independent samples t-test was used to evaluate the differences among different measurements data.P<0.05 was considered statistically significant.Results The EDssde of group A [(1.124±0.314)mGy·cm]was significantly lower than that of group B [(3.542±0.797)mGy·cm],and the difference was statistically significant(P<0.001).The difference in noise between group A and B was statistically significant(P<0.05). The SNR and CNR in the group A were not lower than those in the group B and even the CNR in the partial coronary segment of the group A was higher than that in the group B,exhibiting statistically significant difference(P<0.05).Image quality index in the group A was higher than that in group B,and the difference was statistically significant (P<0.05).Conclusion Compared with conventional coronary CTA examination,"double low"coronary CTA examination in patients with high BMI (26 kg/m2≤BMI≤30 kg/m2)can acquire nice CT images suitable for clinical diagnosis and can significantly reduce the radiation dose and the amount of contrast agent.