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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.
ABSTRACT
PurposeTo analyze the urinary stone chemical composition using dual source CT (DSCT) dual energy imaging.Materials and MethodsNinety-seven stone samples with known chemical composition were placed in fresh swine kidneys and examined with DSCT dual energy scan, including 55 calcium oxalate stones, 13 hydroxyapatite stones, 9 uric acid stones, 4 cystine stones, 2 struvite stones and 14 mixed stones. The mean attenuation values and dual energy index (DEI) were measured at 80 kV and 140 kV. The stone composition was analyzed to determine the sensitivity, specificity and accuracy.ResultsDual energy analysis showed 59 calcium oxalate stones, 11 hydroxyapatite stones, 9 uric acid stones, 4 cystine stones and 14 mixed stones. 2 hydroxyapatite stones were erroneously marked as calcium oxalate stones and 2 struvite stones as calcium oxalate stones. The accuracy was 95.88% (93/97). The difference CT value at 80 kV and 140 kV and DEI value were statistically significant (P<0.05). The sensitivity for detecting calcium oxalate stones, hydroxyapatite stones, uric acid stones and cysteine stones were 100.00%, 84.60%, 100.00% and 100.00%, respectively; with specificity of 85.70%, 100.00%, 100.00% and 100.00%, respectively; and the accuracy were 95.18%, 97.59%, 100.00% and 100.00%, respectively.ConclusionDSCT dual energy imaging accurately analyzes the chemical composition of urinary stone in vitro, which provides important clinical value in analyzing the urinary stonesin vivo.