| Objectives:To evaluate the elasticity of thoracic aorta and related common diseases using retrospective electrocardiogram(ECG)-gated dual-source computed tomography(MDCT),to the assess the arterial stiffness and its change during cardiac cycle of thoracic aorta.To investigate the elasticity of thoracic atherosclerosis,to determine the relationship between arterial stiffness and plaque and its involved range.To assess the elasticity of dilated ascending aorta,which can lead to a better clinical approach.Methods:116 subjects underwent ECG-gated CT examination in our hospital(during 2017.12-2018.12),all subjects were divided into 3 groups:①32 subjects without aortic diseases(19 male,9 female,52.28±13.82years)were divided into 4 groups according to age,group A<40 years,group B 40-49years,group C 50-60years,group D>60 years,according to the aortic anatomical segment there were 3 groups,including ascending aorta,aortic arch and descending aorta;②72 subjects with thoracic atherosclerosis(45 male,27 female,66.89±9.53years)were divided into calcified,mixed,and non-calcified plaque according to the the presence of plaque,with 1 control group,4 groups in all,according to the involved range of plaque there were 4 groups:1st quartile,2nd quartile,3rd quartile,and 4th quartile;③12 subjects with ascending aorta dilation(7 male,5 female,63.75 ± 11.65years)were divided into dilated ascending aorta group and distal site of dilation group according to the lesion form,with 1 control group,3 groups in all.All participants were subjected to retrospective ECG-gated DSCT,before examination patients’ blood pressure are measured.raw data were reconstructed in 5%steps throughout the RR interval and analyzed.We obtained 21 phases images in each participant.ROI(region of interesting)selected on different sites:①Aorta without aortic diseases:ROI selected on ascending aorta(the level of right pulmonary artery),the midpiece of aortic arch and descending aorta;②Thoracic atherosclerosis:ROI selected on the biggest plaque and its involved range was record;③Ascending aorta dilation:ROI selected on the dilated ascending aorta and distal site of dilation.The maximum and minimum diameters and cross-sectional areas of ROI were measured.The aortic elasticity properties:Aortic distensibility(A0D),Aortic compliance(A0C)and Aortic stiffness index(A0SI)were calculated.①Analyze the pulsate rule and elasticity characteristic of aorta,and its relationship with sex,age and blood pressure;②Investigate the elasticity of thoracic atherosclerosis,determine the relationship between arterial stiffness and plaque and its involved range;③Assess the elasticity of dilated ascending aorta.Results:1.The pulsate rule of thoracic aorta:The maximum and minimum diameter and area of ascending aorta are greater than aortic arch and descending aorta,which have significant difference(P<0.05).There is regular diastole and systole of aorta accompanied with the cardiac pulsation,the phase of ascending aorta,aortic arch,descending aorta achieved the maximum and minimum diameter and area have no significant difference(P>0.005).2.The elasticity of thoracic aorta:A0D,A0C,A0SI of ascending aorta and A0D of aortic arch and descending aorta have significant difference in 4 age groups(P<0.05),A0D,A0C were group A>group B>group C>group D,A0SI was group A<group B<group C<group D.A0C,A0SI of aortic arch and descending aorta shows difference only within 2 groups(P<0.05).Aortic A0D,A0C have a negative correlation with age,and A0SI has a positive correlation with age(P<0.05),A0D of aortic arch has strongest correlation(r=-0.63,P<0.05).The elasticity characteristic of different segments of thoracic aorta,sex and blood pressure:A0C of three segments shows difference between group A and B(P<0.05),A0C of ascending aorta are greater than aortic arch and descending aorta;A0D of ascending aorta has a negative correlation with systolic pressure,A0SI of descending aorta has a positive correlation with pulse pressure,and a negative correlation with diastolic pressure(P<0.05);AoSI of female’s ascending aorta is greater than male’s,A0D,A0C of female’s aortic arch are less than male’s,but the elasticity of descending aorta have no significant difference between male and female.3.The elasticity characteristic of thoracic atherosclerosis:Aortic arch:①Comparison of different plaque:A0D,A0C,A0SI of 4 groups have no significant difference(P>0.05);②Comparison of different involved range of plaque:in the group of mixed,and non-calcified plaque,A0D of 1st quartile is greater than 4th quartile,in the group of calcified plaque,A0SI of 1st quartile and 2nd quartile are less than 4th quartile(P<0.05);A0D,A0C of aortic arch with non-calcified plaque have a negative correlation with involved range of plaque(P<0.05).Descending aorta:①Comparison of different plaque:A0D,A0C,A0SI of 4 groups have no significant difference(P>0.05),but in the group of 1st quartile,A0D of calcified plaque is greater than that of non-calcified plaque,A0SI of calcified plaque is greater than that of non-calcified plaque;In the group of 4th quartile,A0SI of calcified plaque is greater than that of control group(P<0.05);②Comparison of different involved range of plaque:in the group of calcified plaque,A0SI of 3rd quartile and 4th quartile are greater than 1st quartile(P<0.05),and A0SI of descending aorta with calcified plaque has a positive correlation with involved range of plaque(P<0.05).4.The elasticity characteristic of dilated ascending aorta:The diameter and area of dilated ascending aorta are greater than that of distal site of dilation group and control group,the phase of dilated ascending aorta achieved the minimum area is later than that of control group(P<0.05).A0D,A0C of 3 groups have no significant difference(P>0.05),but A0SI of them have significant difference(P<0.05),A0SI of dilated ascending aorta is greater than that of distal site of dilation group and control group(P<0.05),but there is no significant difference of A0SI between distal site of dilation group and control group(P>0.05).Conclusions:1.ECG-gated DSCT can perform the real one-step inspection of the evaluation of arterial morphology and function.2.There is regular pulsate of aorta,and the pulsation of three segments is consistent with each other,the elasticity of three segments of thoracic aorta shows difference under 50 years,A0C of ascending aorta is greater than that of aortic arch and descending aorta;The elasticity of aorta decreased with age,ascending aorta is the most sensitive part to age;The elasticity of ascending and descending aorta decreased with systolic pressure,pulse pressure increase and distolic pressure decrease;The elasticity of female’s ascending aorta and aortic arch are less than male’s,but that of descending aorta have no significant correlation with sex.3.Different plaques have impact on the elasticity of descending aorta,but not on aortic arch,big calcified plaque can result in decrease of the elasticity,small non-calcified plaque has greater influence than mixed and calcified plaque;The bigger range the plaque involved,the more severely is the elasticity of thoracic aorta damaged.4.The pulsate of dilated ascending aorta differ from the ascending aorta without aortic diseases and distal site of dilation,the elasticity of dilated ascending aorta decreased,but there is no difference between distal site of dilation and ascending aorta without aortic diseases. |
PDF Full Text Request