The Clinical Research On Evaluating Changes Of Renal Function In Hypertensiv Nephropathy By Contrast-enhanced Ultrasound

Objective: To quantitatively monitor the changes of renal cortical blood perfusion in each period Hypertensive nephropathy(HN)by using Contrast-enhanced ultrasound technology(CEUS),the each quantitative parameter in time-intensity curve(TIC)and renal function index Cystatin C(Cys-C),serum creatinine(Cr),blood urea nitrogen(BUN)were performed correlation analysis,to investigate the value of CEUS in evaluating HN and the sensitivity of CEUS to monitor the changes of HN renal function.In order to provides a reliable method for the diagnosis and treatment of the disease Methods: 45 patients with Essential Hypertension(EH)admitted in the department of Cardiology and Nephrology in Southwest medical university affiliated hospital from September 2015 to December 2016 were enrolled in this study.45 patients were selected as the Lesion group: Including 20 cases of female,25 cases of male,aged 28-63 years old.All the subjects were diagnosed as essential hypertension,And no other kidney disease(Such as renal inflammatory diseases,nephrotic syndrome,renal artery stenosis,polycystic kidney disease,etc.),without the history of renal surgery,and heart failure or other diseases that may affect kidney function,according to the early indicators of renal damage Cys-C and the common indicators of clinical evaluation of renal function that the Cr and BUN,the patients were divided into three groups,each group of 15 cases : In group A,Cys-C(0.51-1.09mg/l),creatinine and urea nitrogen were normal,that the no early renal damage group;group B,Cys-C increased(> 1.09mg/L),creatinine and urea nitrogen were normal,that is,early renal damage group.In group C,Cys-C was higher(> 1.09mg/L),creatinine and urea nitrogen increased,that is,the middle and advanced stage renal damage group.Selected 10 cases of our hospital physical examination of health Adult as control group(N group),its age,weight,height matched with lesion group,no hypertension,no history of kidney disease,kidney surgery history,heart failure or other may affect the kidney function of the disease,long-term follow-up blood pressure,renal function were not abnormal,the kidney images of two-dimensional ultrasound examination were clear and stable.The subjects are fully aware of this experiment,willing to take the initiative to cooperate with the following experimental study,and all signed informed consent.In the early morning of the experiment,blood samples were collected and performed biochemical tests such as Cys-C,BUN and Cr.Before the experiment,Patients of this study should have rest for half an hour,until the blood pressure,heart rate,breathing and other normal level of recovery,then performed routine gray-scale ultrasound and color Doppler ultrasound(CDFI)examination,Check contents: Bilateral renal morphology,size,substance echo,etc.,to exclude the object who is not suitable.Then,the ultrasound diagnostic instrument was converted to contrast-enhanced ultrasound.Sono Vue contrast-enhanced ultrasound inspect the kidney of the patients.the changes of echo intensity in the kidney were observed in real time within 3 min.At the same time,using the machine program to record and store the continuous and dynamic image of renal perfusion.A square interest area of 5mmx5 mm near the membrane area in three parts of the upper,middle and lower cortex were selected,the TIC analysis software built in the instrument was used to analyze change situation and regularity of contrast agent microbubbles in ROI to generate the contrast time-intensity curve(TIC).The selected region of interest was repeated analysis for 3 times,calculate the average.By Gamma-variate,the corresponding quantitative parameters of TIC were obtained : Including Time to peak(TTP),Gradient between start frame to peak frame(Grad),peak intensity(PI),Area under the curve(AUC)and so on.The data collected by the institute and the data obtained were dealt with by SPSS tatistics 17.0 statistical software system,the measured data are the mean ± standard deviation(x ±s)that single factor analysis of variance was used to compare the data between multiple groups,pairwise comparison use the least significant difference method.TIC quantitative parameter value and renal function index value were measured by Pearson in each group,the difference was statistically significant with p<0.05.Results: 45 cases of subjects successfully completed the study of the examination,the inspection process and follow-up were no special discomfort.CEUS examination results:(1)CEUS examination of each group of renal contrast agent perfusion: 8-10 s after injection of contrast agent Sono Vue,The kidneys begin to develop,first,the rapid enhancement of the main renal artery, segmental artery,and dendritic branches,followed by renal cortical enhancement,renal medulla and renal sinus enhancement slightly slower,until the whole kidney was "fireball-like" change.At that time was the peak performance of contrast agent,Then the kidneys began to clear,and the order of clearance was reversed.The TIC of renal cortex contrast agent was asymmetric single peak curve,which was composed of ascending branch,peak value and descending branch.The TIC of the control group(N group)increased sharply and the peak value was higher and the descending branch was flat.Compared with the control group,there was no significant apparent difference of TIC in group A.The TIC of group B was slightly blunt and gentle.The TIC of group C was more slowly and blunt.(2)Analysis of quantitative perfusion parameters of renal cortex CEUS: Comparison of quantification parameters of renal cortical TIC curves between groups: 1)Comparison between group A and group N: There was no significant difference of AUC,PI and Gard between group A and group N(P> 0.05),There was significant difference in TTP(P <0.05),and TTP in group A was longer than that in group N(P <0.05).2)Comparison between group B and group N : The difference of Gard between group B and group N was not statistically significant(P> 0.05).There were significant difference of AUC,TTP,PI between group B and group N(P <0.05),TTP was prolonged,AUC increased and PI decreased in group B.3)Comparison between group C and group N,There were significant difference of AUC,TTP,PI and Gard between group C and group N(P <0.05).In group C,AUC decreased,TTP prolonged,PI decreased and Gard increased.4)Comparison among groups : There was significant difference of AUC,TTP,PI among groups(P <0.05),Compared with group A,B,TTP prolonged,PI decreased in group B and group C,TTP prolongation and PI decreased significantly in group C,Compared with group A,AUC increased in B group,Compared with a group B and group A,AUC decreased in group C,there was no significant difference between group A and group B(P> 0.05).There was no significant difference of Gard between group A and group B(P> 0.05),Compared with a group B and group A,there was significant difference of Gard in group C(P <0.05),Gard in group C was significantly larger.2.There was a significant linear correlation of TTP,PI,AUC,Grad among groups when correlation analysis with renal function sensitive index Cys-C,BUN,Cr and Cys-C,BUN,Cr were negatively correlated with AUC and PI,and was positively correlated with TTP,Grad.Conclusion:(1)Hypertensive patients with or without renal damage,may have abnormal perfusion and it can be found earlier by CEUS;(2)CEUS can dynamically reflect the changes of renal microcirculation blood flow in hypertensive patients;(3)CEUS can be can be a certain extent to reflect the degree of renal damage in hypertensive nephropathy.