Feasibility of Dual Source CT Low Tube Voltage Combined with Iterative Reconstruction in Evaluating Coronary Artery Stents / 中国医学影像学杂志

ABSTRACT

Purpose To investigate the second generation dual source CT low tube voltage (100 kV) combined with sonogram-affirmed iterative reconstruction (SAFIRE) in assessing coronary artery stents. Materials and Methods One hundred and fifty-six patients underwent CT coronary angiography after implanted coronary artery stents. Among all the patients, 86 cases were performed with 100 kV combined with SAFIRE, and 70 cases with 120 kV combined with filtered back projection reconstruction (FBP). Mean CT values, image noise, SNR, SAIR, image quality scores, stents detecting and radiation dose of aortic root, inner-stent, and the coronary artery proximal to the stent were compared. Results The mean CT value of aortic root, inner-stent, and the coronary artery proximal to the stent of 100 kV group was higher than that of 120 kV group (t=2.75, 11.77 and 3.19, P0.05). There was no statistic difference of image quality score between the two groups (t= -0.203, P>0.05). Totally there were 243 stents detected, including 67 of right coronary artery, 123 of left anterior descending, 36 of left circumflex, and 17 of other branches. Stent length ranged 3.8 to 98.7 mm and averaged (27.5±16.4) mm. The CTDIvol, DLP and ED of 100 kV group were lower than those of 120 kV group (t= -11.03, -9.41 and -9.41, P<0.05). The effective dosage reduced about 51.5% in 100 kV group when compared with that of 120 kV group. Conclusion The second generation dual source CT low tube voltage (100 kV) combined with SAFIRE in assessing coronary artery stent could meet the diagnostic requirement and reduce the radiation dosage, without increasing image noise and beam hardening artifacts.