The Clinical Application Of Reduce Radiation Dose On Dual-energy Coronary Computed Tomography Angiography

Objective(1)To explore the feasibility of low mAs dose and safire technology dual energy coronary CTA check.(2)To explore the feasibility of low mAs dose and safire technology dual energy coronary CTA on Patients with different body mass index.(3)Compared with DSA coronary angiography,To evaluate the value of Dual-Energy Coronary CTA in the assessment of coronary artery stenosis diseases.Materials and Methods(1)240 patients(age 27-84 years old, heart rate(HR)<75bpm and no arrhythmia,19 kg/m2≤BMI<24 kg/m2)were scanned on a dual source CT under dual-energy coronary CTA mode.The tube voltage values were set to 100 kV (tube A) and 140 kV with tin filter using fixed tube current ratio. All of inspectors according to A ball tube current were randomly divided into four groups, conventional group A(180mAs)and low-dose group B-D (150mAs,120mAs,90mAs), the third of sinogram-affirmed iterative reconstruction(SAFIRE 3) methods by using the low-dose group;The differences in mean CT values, image noise (SD), signal-to-noise ratio(SNR), contrast-to-noise ratio(CNR),subjective image quality scores (SIC), and effective radiation dose(ED) between four groups were compared.(2)Another 240 patients(age 27-83 years old, heart rate<75bpm and no arrhythmia) were scanned on a dual source CT under dual-energy coronary CTA mode. There were divided to four groups according to body mass index,The tube voltage values were set to 100 kV (tube A) and 140 kV with tin filter using fixed tube current ratio.Group 1(19≤BMI<24),A Tube of 180mAs,and filtered back projection(FBP).Group 2(BMI <19),A Tube of 60mAs;Group 3(19≤B<MI24),A Tube of 90mAs;Group 4 (24≤BMI <30),A Tube of 120mAs; Group 2-4 adopt the third of sinogram-affirmed iterative reconstruction(SAFIRE 3).The differences in mean CT values, image noise (SD), signal-to-noise ratio(SNR), contrast-to-noise ratio(CNR) subjective image quality scores (SIC), and effective radiation dose(ED) between four groups were compared. (3)52 patients in DE-CCTA were also used DSA coronary artery angiography,the interval time of two check were less than 5 days,the results of DE-CCTA and DSA-CAG were retrospectively reviewed evaluating the accuracy of the coronary artery stenosis in DE-CCTA.The differences of coronary artery stenosis in sensitivity(Sen),specificity(Spe),false positive(FPR),false negative rate(FNR),positive predictive value(PV+),negative predictive value(PV_),Youden’s index(y),consistency percent(CP) were analyzed in DE-CCTA.Results(1)There was no statistical difference between the 180mAs group and 90mAs with SAFIRE 3 group (P>0.05). Age,HR,BMI,LEN,display segment of coronary, and mean CT values,There was no statistical difference between the four groups. the SD,SNR,CNR statistical difference, By SAFIRE 3,Each group of SD value decreased significantly, SNR and CNR are rising and statistical difference(P<0.05);Image quality,SNR,CNR is highest in 150mAs with SAFIRE 3 group,SD is lowest;B> C>D-A.There are opposite to the 180mAs group and 90mAs with SAFIRE 3 group. The effective radiation dose (ED=5.50±1.47mSv、4.55±1.16mSv、3.41±0.77mSv、 2.44±0.67mSv) of each group were statistically significant(P<0.05).(2)Age,HR,LEN,display segment of coronary, CT values, SD,SNR,CNR, and score, There was no statistical difference between the four groups(P>0.05).The effective radiation dose (ED=5.50±1.47mSv、1.88±0.44mSv、2.39±0.78mSv、4.17±1.02mSv) of each group were significantly(P<0.05). Group 2-4 reduce by 65.82%、56.55%、 24.18% in ED. average value is (2.81±1.18) mSv, reduce by 48.91%.(3)It had a very good consistency in evaluating the stenosis degree of coronary artery between DE-CCTA and DSA-CAG(Kapps=0.840,P<0.05).The diagnosis sensitivity (Sen), specificity (Spe), false positive(FPR),false negative rate(FNR), positive predictive value(PV+),negative predictive value(PV_),Youden’s index(y),consistency percent(CP) of coronary artery stenosis were 94.3%,94.9%,5.1%,5.7%,81.1%,98.6%, 0.892 and 94.8%.The area under curve of ROC of DE-CCTA in dignosis of moderate and severe stenosis(≥50%) was 0.979.Conclusion(1)DE-CCTA at tube current of 90 mAs by safire can significantly reduce the radiation dose without reducing image quality,thus it has a good prospect of application.(2)DE-CCTA with low tube current at different BMI by safire can significantly reduce the radiation dose without reducing image quality,Lay a foundation for the one-stop inspection.Achieve the goal of personalized based on effective to reduce radiation dose.(3)DE-CCTA as heart one-stop examination of imaging technology,, is valuable for the diagnosis of coronary artery stenosis, especially for moderate and severe stenosis.