An Application Study Of Assessment Of Coronary Stent Implantation By DSCT

Objective The patients with coronary stent implantation were performed on DSCT coronary angiography examination to investigate the impact of stent on restenosis after coronary stent implantation. The accuracy and advantages of restenosis after coronary aren't implantation were evaluated by DSCT coronary angiography in comparison of CAG in order to provide guidance in the diagnosis and treatment of restenosis after coronary stent implantation.Material and Methods 96 patients with coronary stent implantation (160 stents and the time of stent implantation ranged from 3 to 40 months) from March to December 2009 at 1st affiliated hospital of Kunming Medical University were performed on DSCT coronary angiography, who were divided into two groups:group A:46 patients with 65 stents:detailed stent manufacturers, material, lumen diameter and thickness; and group B:40 patients with 66 stents were performed on CAG within two weeks. The patients were performed on DSCT to analyse general axial plane images and two-dimensional and three-dimensional images which were post-processed by Circulation software. In group A:60 stents can be used to analyse the correlation between stent lumen size, stent diameter, the levels of vascular, thickness, material, the degree of calcification, the time of stent implantation and the image quality of DSCT coronary angiography. In group B, 61 stents can be used to assess restenosis through comparing DSCT coronary angiography and CAG.Moreover the reasons for ISR can be initially evaluated through calculate its sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) by DSCT.Results:160 stents in 60 patients all were showed, in which 153 stents (95.6%) can be used to evaluate; and only 4 stents (4.4%) can't. There had statistical difference in comparison the image quality of DSCT coronary angiography with stent lumen size, stent diameter, the levels of vascular, thickness, material, the degree of calcification (P<0.05). The level of vascular can affect the image quality of DSCT coronary angiograph. The higher the level of vascular, the worse the image quality. Stent lumen size can also affect the image quality of DSCT coronary angiograph. The smaller stent lumen, the worse the image quality. Stent thickness can also affect the image quality of DSCT coronary angiograph. The image quality was worse in comparison stent thickness>0.1mm with stent thickness=0.1mm.The impact of stainless steel stent on DSCT coronary angiograph was different from other material. There weren't obvious differences between nickel titanium and cobalt alloys; however, the image quality of nickel titanium and cobalt alloys was better than stainless steel stent for less artifacts. Calcification around stent can also affect the image quality of DSCT coronary angiograph. The more the calcification, the worse the image quality.There wasn't statistical difference between the time of stent implantation and the image quality(P>0.05). In group B:the sensitivity of diagnosis of in stent restenosis is 96.5%, the specificity is 91.7%, PPV is 90.3% and NPV is 97.1%. ROC curve Area= 0.965, which is a high correlation.61 stents in group B were showed, in which 27 were ISR,9 Simple stenosis or occlusion (0.33%),7 soft plaque(0.26%),5 moderate plaque(0.19%),5 calcium plaque (0.19%),1 stent deformation (0.03)% by DSCT.Conclusion:1. DSCT coronary angiography is used to assess coronary stent implantation as a non-invasive method, which has advantages, such as easy and fast scan, wide indications and high success rate.2. The image quality of DSCT coronary arterial is affected by the levels of vascular, stent material, stent diameter, wall thickness and the degree of calcifications, while is not affected by the time of stent implantation.3. There has higher accuracy of evaluation of in-stent restenosis after coronary stent implantation, which can avoid unnecessary CAG examination and becomes a reliable and non-invasive method. 4. Through DSCT coronary angiography, we can not only determine in-stent restenosis after coronary artery implantation, but also observe the morphological changes of the cavity and wall density, moreover, indirectly speculate the reasons for restenosis.