256iCT In Evaluation On Correlation Of The Coronary Plaque And Transluminal Attenuation Gradient In The Lumen Of The Coronary Artery

Objectives 1 To explore the correlation between transluminal attenuation gradient of coronary artery lumen and the degree of coronary stenosis by 256 slice spiral CT.2 To explore the correlation of coronary plaque calcification score,plaque composition and plaque extent with coronary artery attenuation gradient by 256 slice spiral CT.Methods 1 Dealing with 72 suspected coronary heart disease patients who had taken Coronary computer tomography angiography and would performed digital subtraction angiography one week later in North China University of Science and Technology Affiliated Hospital,which totally includes 216 main branch vesseeis.Compared with the results of DSA as the gold standard,the three main coronary artery stenosis were divided into normal group(n=48)and stenosis group(n=168)by whether they have coronary or not.And then the stenosis group were divided into mild(n=48),moderate(n=50),severe(n=54)and occlusion group(n=16)according to the degree of stenosis.The general clinical data of the patients were recorded.The CT values of each vessel were measured to calculate transluminal attenuation gradient.2 Dealing with 148 suspected coronary heart disease patients who had taken Coronary computer tomography angiography in North China University of Science and Technology Affiliated Hospital,which totally includes 444 main branch vesseeis.According to whether coronary artery calcification existed or not,all patients were also divided into calcification negative group(n=231)and calcification positive group(n=213).The calcification positive group was further divided into light(n=57),medium(n=72),and serious groups(n=84)according to the calcification scores.According to whether coronary artery plaque existed or not,all patients were also divided into plaque negative group(n=156)and plaque positive group(n=288).The plaque positive group was further divided into calcified plaque(n=87),non-calcified plaque(n=75),and mixed plaque(n=126)according to the plaque composition.The plaque positive group was further divided into focal plaque(n=87),segmental plaque(n=93),and diffuse plaque groups(n=108),according to plaque extent.The calcification integral,the plaque composition and plaque were recorded,and the attenuation gradient in the lumen was calculated.All data was strictly proofread,using SPSS 22.0 statistical software for statistical analysis.The measurement data compared by t-test,rank-sum test and one-way repeated measures ANOVA,intragroup pairwise compared by SNK test;two groups or multiple sample rate and composition ratio compared with the chi square test;the correlation relationship between transluminal attenuation gradient and multiple factors by Spearman correlation analysis.There was statistically significant of P<0.05.Results 1 Transluminal attenuation gradient of normal group and stenosis group were:-2.34±1.03 HU/10 mm and-6.44 ± 6.55 HU/10 mm.There was significant difference in the two groups(P<0.05).The TAG value of mild,moderate,severe and occlusion group respectively were-2.07±2.21 HU/10 mm,-3.58± 2.74HU/10 mm,-10.84±5.97 HU/10 mm,and-13.99±8.59 HU/10 mm,P<0.05,the difference was statistically significant.The correlation between transluminal attenuation gradient and the severity of coronary artery stenosis was negative related.2 The TAG value of calcification negative group and calcification positive group were:-3.64±4.00 HU/10 mm and-7.99±5.56 HU/ 10 mm.The TAG value were lower in calcification positive group than those in calcification negative group(P<0.05).The TAG value of light calcification group,moderate calcification group and serious calcification group respectively were-2.74±2.52 HU/10 mm,-6.71±4.54 HU/10 mm and-12.65±3.84 HU/10 mm.There were significant differences in TAG among light,medium,and serious groups in calcification positive group(P<0.05).3 In the plaque negative group,TAG=-2.01±2.14 HU/10 mm,In the plaque positive group,TAG=-7.74±5.38 HU/10 mm,P<0.05,the difference was statistically significant.The TAG value of calcified plaque,non-calcified plaque,and mixed plaque respectively were-7.93±5.40 HU/10 mm,-7.04±4.79 HU/10 mm,-8.03±5.69 HU/10 mm,P> 0.05,the difference was no statistically significant.4 The plaque positive group was further divided into focal plaque,segmental plaque,and diffuse plaque groups according to plaque extent,The TAG value respectively were-3.15±2.52 HU/10 mm,-6.22±4.29 HU/10 mm,-12.76±3.48 HU/10 mm.P< 0.05,the difference was statistically significant.5 Spearman correlation analysis was used to analyze the correlation of multiple factors.The results showed that there was negative correlation between calcification integral and plaque extent to the attenuation gradient in the lumen,(coefficient of correlation were-0.704,-0.748,P<0.05).However,there was no significant correlation relationship between plaque composition and intracavitary attenuation gradient(coefficient of correlation was-0.419,P>0.05).Conclusions 1 There was a negative correlation between TAG and the degree of coronary artery stenosis,when the coronary artery was severe stenosis,the decrease of TAG value was more significant.Observation of TAG value can reflect the hemodynamic changes of coronary artery and improve the diagnostic value of functional stenosis of coronary artery.2 There was a negative correlation between TAG and coronary artery calcification score.When coronary artery presented severe calcification,TAG was significantly decreased.Coronary artery calcification score can be used as an effective index to predict coronary functional stenosis.3 There was no correlation between TAG and plaque composition of calcified artery.4 There was a negative correlation between TAG and plaque extent,and the TAG value decreased gradually with the increase of plaque extent.When the plaques were diffuse,the TAG value decreased significantly.