速度向量成像技术评估吸烟大学生颈总动脉管壁运动的意义

Assessment of mechanical properties of common carotid artery in somking students using velocity vector imaging

目的探讨速度向量成像(VVI)技术评估吸烟大学生颈总动脉管壁运动的意义。方法选择在校吸烟大学生25名作为吸烟组,在校非吸烟大学生25名作为对照组,常规超声测量颈总动脉扩张期内径及内中膜厚度。应用VVI技术对这2组大学生颈总动脉前壁、前内侧壁、后内侧壁、后壁、后外侧壁、前外侧壁6个壁段的运动情况进行量化分析并进行比较。结果吸烟组与正常对照组颈总动脉内中膜厚度及内径比较差异均无统计学意义。吸烟组及对照组组内比较时,前壁、前内侧壁、后内侧壁、后壁、后外侧壁、前外侧壁6个壁段间的径向速度负向峰值(Pv)、切向应变正向峰值(Ps)、应变率正向峰值(Psr)、径向位移负向峰值(Pd)差异均无统计学意义。吸烟大学生颈总动脉前壁、前内侧壁、后内侧壁、后壁、后外侧壁、前外侧壁的Ps分别为(4.39±2.94)%、(4.64±3.06)%、(5.07±2.82)%、(4.62±2.58)%、(4.75±2.82)%、(4.49±2.64)%,Psr分别为(0.37±0.26)/s、(0.39±0.28)/s、(0.41±0.27)/s、(0.38±0.25)/s、(0.39±0.26)/s、(0.37±0.24)s,均低于对照组的(6.37±2.06)%、(6.20±1.85)%、(6.39±1.98)%、(6.71±3.54)%、(6.41±2.81)%、(6.35±2.16)%、(0.54±0.21)/s、(0.52±0.19)/s、(0.54±0.19)/s、(0.55±0.23)/s、(0.54±0.21)/s、(0.52±0.19)s,差异均有统计学意义(t=-3.687,P=0.000;t’=2.813,P=0.007;t’=2.499,P=0.015;t=3.098,P=0.003;t=2.749,P=0.007;t’=3.578,P=0.001;t=3.338,P=0.001;t’=2.493,P=0.015;t’=2.490,P=0.015;t=3.313,P=0.001;t=3.084,P=0.003;t’=3.230,P=0.002),而各壁段Pv、Pd与对照组比较差异无统计学意义。吸烟大学生颈总动脉前壁、前内侧壁、后内侧壁、后壁、前外侧壁的径向速度正向达峰时间标准差(Tv-SD)分别为(46±63)、(82±99)、(13±140)、(102±121)、(58±54)ms,切向应变负向达峰时间标准差(Ts-SD)分别为(25.8±47.4)、(29.6±61.5)、(9.2±14.7)、(1.1±22.8)、(10.2±16.6)ms,切向应变率负向达峰时间标准差(Tsr-SD)分别为(30.9±60.4)、(37.5±76.1)、(9.3±12.5)、(10.1±14.5)、(11.3±13.8)ms,均高于对照组的(18±23)、(30±42)、(54±77)、(48±64)、(34±42)、(8.3±29.8)、(4.0±7.7)、(2.6±4.8)、(1.9±2.8)、(10.2±19.2)、(8.3±28.6)、(4.1±8.2)、(2.8±4.8)、(2.2±3.0)、(3.9±4.9)ms,差异均有统计学意义(t’=-2.668,P=0.010;t’=-3.135,P=0.003;t’=-3.218,P=0.002;t’=-2.567,P=0.013;t’=-2.367,P=0.021;t’=-2.064,P=0.043;t’=-2.620,P=0.012;t’=-2.714,P=0.009;t’=-2.460,P=0.018;t’=-2.147,P=0.042;t’=-1.650,P=0.049;t’=-2.147,P=0.042;t’=-2.474,P=0.020;t’=-2.659,P=0.014;t’=-2.565,P=0.017),而各壁段径向位移正向达峰时间标准差(Td-SD)与对照组比较差异无统计学意义。结论在颈总动脉形态学指标发生改变之前,VVI技术可以通过对动脉管壁运动特性的分析更早地评价吸烟者颈总动脉病变情况。

Objective To discuss the value of velocity vector imaging (VVI) technique used in the assessment of the common carotid arterial wall motion in the smoking students. Methods Twenty-five smoking students were included as the case group and 25 non-smoking students as the normal control group. Two-dimensional dynamic images of the common carotid artery (CCA) were obtained by Siemens Acuson Sequoia C512 color Doppler ultrasound in both groups. The internal diameter and intima medium thickness (IMT) of the CCA during its expansion were measured .Then the six segments of the common carotid artery wall (anterior wall, posterior wall, anterolateral wall, anterior internal wall, posterolateral wall and posterointernal wall) were analyzed quantitatively and compared mutually by VVI technique. Results There were no significant differences of IMT( t=-1.253, P=0.218), and internal diameter( t =-0.501, P=0.619) of the CCA between the smoking and the non-somking students. Besides that, there were no significant differences of movement parameters (Pv,Ps,Psr,Pd) of these six segments between the somking group and the non-smoking group( P>0.05) . The positive peaks of circumferential strain(Ps) of anterior wall, anterior internal wall, posterointernal wall, posterior wall, posterolateral wall and anterolateral wall in the smoking group were (4.39±2.94)%,(4.64±3.06)%,(5.07±2.82)%,(4.62±2.58)%,(4.75±2.82)%,(4.49±2.64)%, respectively,while the positive peaks of circumferential strain rate(Psr)were (0.37±0.26)/s,(0.39±0.28)/s,(0.41±0.27)/s,(0.38±0.25)/s,(0.39±0.26)/s,(0.37±0.24)s. These motion parameters of non-smoking group were (6.37±2.06)%,(6.20±1.85)%,(6.39±1.98)%,(6.71±3.54)%、(6.41±2.81)%,(6.35±2.16)%,(0.54±0.21)/s,(0.52±0.19)/s,(0.54±0.19)/s,(0.55±0.23)/s,(0.54±0.21)/s,(0.52±0.19)/s which were lower than the smoking group. Differences were statistically significant( t=-3.687,P=0.000;t’ =2.813,P=0.007;t’=2.499,P=0.015;t =3.098,P=0.003;t =2.749,P=0.007;t’=3.578,P=0.001;t =3.338,P=0.001;t’=2.493,P=0.015;t’=2.490,P=0.015;t =3.313,P=0.001;t =3.084,P=0.003;t’=3.230,P=0.002). But, the negative peaks of radial velocity(Pv) and displacement(Pd) had no significant differences( P>0.05) . The Standard devitions of time to positive peak velocity(Tv-SD) of these five segments(anterior wall, anterior internal wall, posterointernal wall, posterior wall, anterolateral wall) were (46±63)ms,(82±99)ms,(13±140)ms,(102±121)ms,(58±54)ms, while standard devitions of time to negative peak strain(Ts-SD) were (25.8±47.4)ms,(29.6±61.5)ms,(9.2±14.7)ms,(1.1±22.8)ms,(10.2±16.6)ms and strain rate Tsr-SD were (30.9±60.4)ms,(37.5±76.1)ms,(9.3±12.5)ms,(10.1±14.5)ms,(11.3±13.8)ms. These parameters in the smoking group were (18±23)ms,(30±42)ms,(54±77)ms,(48±64)ms,(34±42)ms,(8.3±29.8)ms,(4.0±7.7)ms,(2.6±4.8 )ms,(1.9±2.8)ms,(10.2±19.2)ms,(8.3±28.6)ms,(4.1±8.2)ms,(2.8±4.8)ms,(2.2±3.0)ms,(3.9±4.9)ms. These motion parameters in somking students were decreased significantly compared with the controls( t’=-2.668,P=0.010;t’=-3.135,P=0.003;t’=-3.218,P=0.002;t’=-2.567,P=0.013;t’=-2.367,P=0.021;t’=-2.064,P=0.043;t’=-2.620,P=0.012;t’=-2.714,P=0.009;t’=-2.460,P=0.018;t’=-2.147,P=0.042;t’=-1.650,P=0.049;t’=-2.147,P=0.042;t’=-2.474,P=0.020;t’=-2.659,P=0.014;t’=-2.565,P=0.017). There was no significant difference of standard devitions of time to positive peak displacement(Td-SD)between the two groups( P>0.05).Conclusion VVI technology has an earlier assessment of the common carotid artery lesions in smokers through the analysis of arterial wall motion characteristics ,before the morphological indicators change.