The Experimental Study Of Renal Artery Stenosis With Ultrasound

SectionⅠDoppler Ultrasound in Diagnosis of Renal Artery Stenosis(RAS):Experimental StudyObjectives:To make acute rabbit RAS model of different level,by the use of Doppler ultersound to study hemodynamics of renal artery and renal intrinsic artery and to evaluate the value of Doppler ultersound.Methods:the left renal arteries of 10 rabbits were progressively stenosed at several level. to include these level:0 degree-normal level,Ⅰdegree-to stenose 1/3 of the artery,Ⅱdegreeto stenose 2/3 of the artery,Ⅲdegree-obstruct the artery.By the use of Doppler ultrosound, peak systolic velocity(V_p)to the renal artery of these level was measured.Blood flow parameters such as V_p.end diastolic velocity(V_m),accelaration time(AT),acceleration(ACC),resistance (RI)of interlobar arteries in these level were measured.Results:1.Shape of spectra of renal arteries and interlobar arteries:When renal arteries were stenosed 1/3,the spectra of the segment showed high speed.Interlobar arteries showed nearly invariably.When renal arteries were stenosed 2/3,the spectra of the segment showed higher speed.Interlobar arteries showed round and blunt.When renal arteries were obstructed, there were no signal of blood.2.Blood flow parameters of renal arteries and interlobar arteries of different level:inⅠdegree andⅡdegree group.V_p was higher than 0 degree group,V_p inⅡdegree group was higher than that ofⅠdegree group(P＜0.05).V_p,V_m,ACC,RI of interlobar arteries in degree group was lower than in 0 degree andⅠdegree group.There was no significant difference between 0 degree andⅠdegree group.AT inⅡdegree group was longer than that of in 0 degree andⅠdegree group(P＜0.05),There was no significant difference between 0 degree andⅠdegree.Conclusions:1.When renal arteries were stenosed 1/3,V_p of local renal arteries heightened. There was no significant difference in indexes representing hemodynamic of renal interlobar arteries.2.When renal arteries were stenosed 2/3,V_p of local renal arteries heightened.There was significant difference in indexes representing hemodynamic of renal interlobar arteries.----To evaluate the indexes representing hemodynamic of local renal arteriy and renal interlobar arteries is helpful to diagnosis RAS.SectionⅡReal Time Gray-scale Ultrasound Contrast Imaging Study on Perfusion of Renal Artery Stenosis:Experimental StudyObjectives:To study the enhancement pattern of kidney of rabbit RAS model using contrast tuned imaging and to quantify the hemodynamic parameters using time-intensity curve.Methods:Models building vide supra.Renal perfusion and time-intensity curve were evaluated at every stenosis level after contrast injection at bolus by the use of contrast tuned imaging(enTI)gray scale ultrasound examination.Wash-in/Wash-out software was used to estimate the following parameters:time to enhancement(ET),peak signal intensity(PSI),area under curve(AUC),et al.These parameters were obtained from time-intensity curve.Region of interests was placed on cortex and segmenti anterior.Results:1.Enhancement pattern of ultrasound contrast imaging:renal segmenti anteriors, interlobar arteries,cortex,medulla were enhanced by turns.When models were stennosed gradually severitily,time to enhancement was gradually delayed.The enhancement level was gradually weaken.When renal arteries were obstructed,there were no enhanced signal of kidneys. 2.To compare these parameters obtained from the time-intensity curve:in cortex or segmenti anterior,as models were stennosed gradually severitily,ET was gradually delayed,AUC and PSI were both gradually lower(P＜0.05).Ascending slop inⅡdegree group was lower than that in 0 degree andⅠdegree group,the difference was statistically significant(P＜0.05).The difference was no statistically significant in 0 degree andⅠdegree group.Conclusions:1.To observe the ultrasound enhancement pattern of ischemia kidney of renal artery stenosis is helpful to early discover RAS.2.Quantitative analysis of the perfusion of RAS using time-intensity curve is helpful to evaluate the perfusion of ischemia kidney.