Low dose dual-energy coronary artery CTA combined with affirmed iterative reconstruction technique for overweight patients / 实用放射学杂志

ABSTRACT

Objective To evaluate the feasible of dual-energy coronary artery CTA combined with affirmed iterative reconstruction technique for overweight patients.Methods 60 cases underwent dual-energy coronary artery CTA were enrolled in this reasearch.Patients were divided into two groups according to different reconstruction arithmetic model:group A with FBP reconstruction model,while group B with SAFIRE reconstruction model and monoenergetic images from 65 to 90 keV (with increment of 5 keV).All the data were measured by one doctor worked in CT department for more than 5 years,and the image quality were analyzed and evaluated by two senior radiologists.Randomized block ANOVA analysis was used to compare objective evaluation indices of different monoenergetic images from 65 to 90 keV to get the best keV level.The comparative t-test was applied to objective evaluation indices(CT values,SD,SNR,CNR and image quality score) of group A and B and comparative x2-test was applied to image quality score at the best keV level.Results There were significant differences in CT value,SD,SNR,CNR of different keV images (P ＜0.05).For objective evaluation of image quality,the SNR and CNR of group B were significantly higher than group A,and SD was significantly lower than group A (P＜0.05).For subjective evaluation of image quality,there were statistically significant difference between group B and group A (P＜0.05),the segment score of group B was superior to group A.Radiation dose:the DLP value was (238.7±30.82) mGy · cm,and the ED value was (3.3±0.43) mSv.Conclusion SAFIRE combine with purified single spectrum technique can improve the image quality and reduce radiation dose in dual-energy coronary artery CTA,and 75 keV is the best single energy level.