Assessment of coronary stent lumen visibility and patency by dual-source computed tomographic angiography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To assess the in-stent lumen visibility and image quality of coronary stents by dual-source computed tomography (DSCT) coronary angiography, and the diagnostic accuracy of DSCT in the detection of coronary in-stent restenosis.</p><p><b>METHODS</b>DSCT was performed at 147 stents in 78 patients at an interval of (21.8?22.2) months after coronary stent implantation. Axial multi-planar reconstruction of the stents and curved-planar reconstruction through the median of the stents were evaluated for stent image quality on a 5-point scale, and the stent lumen diameters were detected. Thirty out of these 78 patients underwent conventional coronary angiography within one month after CT angiography. The patency of 60 stents were independently evaluated by two blinded readers.</p><p><b>RESULTS</b>Image quality was good to excellent on average score (1.6?0.6) . Stent image quality score was correlated with stent diameter, stent location, and heart rate. All stents were assessable in lumen visibility with an average visible lumen diameter percentage of (72.2?12.2) %. Visible lumen diameter percentage was correlated with stent diameter and stent location. For the stents with calcified plaques, the visible lumen diameter percentage at the calcified site was significantly lower than that at the non-calcified site (P<0.001) . Compared with the conventional coronary angiography, 12 out of 14 in-stent stenoses were correctly detected. The sensitivity, specificity, positive predictive value, and negative predictive value for the detection of in-stent stenosis was 85.7%, 95.7%, 85.7%, and 95.7%, respectively. For stents whose diameter >0.275cm, the sensitivity, specificity, positive predictive value, and negative predictive value were all 100%. The agreement between CT findings and coronary angiography results was 93.3%, and it was correlated with stent diameter and heart rate.</p><p><b>CONCLUSIONS</b>Using a DSCT, coronary stent lumen is partially visible and the image quality is high. Stent diameter and location can influence the stent lumen visibility and image quality. DSCT has a high diagnostic accuracy for the detection of in-stent restenosis and may be a valuable modality for the follow-up of coronary artery stent patency."</p>

Comparison of prospectively electrocardiographic triggered spiral and sequential acquisition for coronary computed tomographic angiography using dual-source computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the image quality and radiation dose of prospectively electrocardiogram (ECG) -triggered spiral and sequential acquisition for coronary computed tomographic angiography by dual-source computed tomography.</p><p><b>METHODS</b>Sixty patients with suspected or known coronary artery disease were randomly divided into two groups. Group A underwent prospective ECG-triggering spiral scan and Group B underwent prospective ECG-triggering sequential scan. Both the image quality and radiation dose of the two groups were compared.</p><p><b>RESULTS</b>There was no significant difference in age and body mass index of the two groups. The average image quality score was 1.12 ± 0.38 in group A and 1.14 ± 0.38 in group B (Z=-0.291,P=0.771) . The rates of diagnostic coronary segments for two groups were 98.87% and 99.56% respectively (X2=0.59,P=0.443) . The mean radiation dose of group A was significantly lower than that of group B [ (1.31 ± 0.30) mSv vs. (3.36 ± 0.93) mSv; t=11.47, P=0.000] .</p><p><b>CONCLUSION</b>Compared with the prospective ECG-triggered sequential acquisition, the prospective ECG - triggered spiral scan for coronary computed tomographic angiography can remarkably reduce radiation dose without impairing image quality in patients with a low and stable heart rate (≤ 70 bpm) .</p>