Contrast-enhanced Ultrasound Assessment Renal Perfusion Of Patients With Chronic Renal Failure

Abstract【Objective】This paper is to explore the renal function evaluation's clinical value which used paired observation and quantitative analysis between chronic renal insufficiency patients and normal people's renal blood perfusion by using real-time contrast-enhanced ultrasound quantitative analysis technique, in order to study the correlation between perfusion parameters and level of serum creatinine as well as blood urea nitrogen.【Methods】Subjects were divided into case group and control group. In case group, there were 36 chronic renal sufficiency diagnosed patients, including 19 males and 17 females; age from 20 to 79, mean age is 46.76±7.31 years old; while the control group had 5 healthy volunteers and clinical exclusion of heart blood vessels, lung and renal disease,37 cases of extra-renal disease, of which 20 males and 22 females, aged 21 to 74; average age is 34.81±6.23 years old. First all examinee were tested the level of serum creatinine and urea nitrogen. Then, they had a routine renal ultrasonography on PHILIPS iU22. Finally, examinee had their real-time contrast-enhanced ultrasound by 1.2ml SonoVue's bolus injection in each kidney through elbow intravenous. Random QLAB image analysis software was used for quantitative analysis and ROI was placed in renal cortex. The echo signal intensity of contrast agent within the ROI was calculated to generate time-intensity curves (TIC curve), then renal ultrasound perfusion parameters was obtained through gamma fitting formulas, including Area Under Curve(AUC), Slope Rate of Ascending Curve(A), Peak Intensity(PI), Time to Peak (TTP), Slope Rate of Descending Curve (α).【Results】Contrast-enhanced ultrasound real-time observation and quantitative analysis showed that the order of the enhancement and the clearance of ultrasound contrast agent in left, right kidney of the case group and control group had no significant difference. Real-time observation:the enhancement speed of cases group was slower than control group, as well as peak intensity of renal cortex and contrast agents extinction. Contrast agent distribution in enhanced region was sparse and rough than in the control group. Quantitative analysis:the case group compared with the control group, showed that the TIC curve increased slower and decreased slower, and time to reach the peak also was slower. The quantitative perfusion parameters of renal cortical perfusion AUC increased, PI reduced, A increased, TTP extension, and the case group was significant different from the control group(P<0.05);αincreased but had no significant difference from the control group (P> 0.05). Renal perfusion parameters of TIC curve had a good correlation with the level of serum creatinine and urea nitrogen. AUC, TTP, A and serum creatinine, blood urea nitrogen was positively correlated.PI and serum creatinine, blood urea nitrogen was negatively correlated.【Conclusions】Real-time quantitative analysis of contrast-enhanced ultrasound can observe the blood flow process in renal cortical in real-time. The perfusion parameters of TIC curve of quantitative analysis can reflect true level of the renal cortical perfusion of the chronic renal failure patients as well as they had a good correlation with the level of serum creatinine and blood urea nitrogen. Real-time quantitative analysis of contrast-enhanced ultrasound is safe and non-invasive, simple and quick, repeatable detection. It is useful for early diagnosis, monitoring follow-up and clinical evaluation in clinical renal failure.