The Application Value Of Contrast-enhanced Ultrasound In Early Grading Diagnosis Of Blunt Renal Injury And The Significance Of HGF And TGF-β1in Kidney After Injury

Objectives:1. To study the establishment of experimental animal models of blunt renalinjury and the ultrasound imaging characteristics of renal injury.2. To explore the application value of contrast-enhanced ultrasound (CEUS)in grading diagnosis of renal injury.3. To study the pathological characteristics and the expression ofhepatocyte growth factor (HGF) and transforming growth factor-beta1(TGF-β1)in kidney early after renal injury.4. To study the significance about changes of HGF and TGF-β1in kidneyearly after renal injury.Methods:1.36rabbits were divided into control group (n=4) and trauma group (n=32)randomly. The32rabbits in trauma group were divided into the four unitsrandomly by different height (h1=30cm, h2=40cm, h3=50cm, h4=60cm).2. Conventional ultrasound and CEUS were used to observe the imaging characteristics of normal kidneys.3. The blunt renal injury was caused by weight falling down to the renalregion by using self-made miniature impactor.4. Conventional ultrasound and CEUS were used to examine the imagingcharacteristics of injured kidneys. The ultrasonic grading diagnosis of renalinjury was made after ultrasound examination.5. The rabbits were put to death and the kidneys of the rabbits were cut offafter ultrasound examination. The pathological grading diagnosis of renal injurywas made after visual observation.6. The sensibility, specificity, accuracy and consistency of CEUS in gradingdiagnosis of renal injury were compared with that of conventional ultrasound.7. The pathological characteristics and the expression of HGF and TGF-β1in kidney after injury were studied by the staining methods of hematoxylin andeosin (HE) and immunohistochemistry (IHC).Results:1. There were different injuries in62kidneys and no significantpathological injury in the other two kidneys. Of the62cases injured,8weregradeⅠ,11were grade Ⅱ,15were grade Ⅲ,21were grade Ⅳ, and7weregrade Ⅴ.2. The renal subcapsular hematomas appeared to be arc-shaped echolessarea when examined by ultrasound. There were not clear demarcation betweenthe normal regions and injured regions which appeared to be hyper-echoes orhypo-echoes when examined by conventional ultrasound. There were distinctdemarcation between the injured regions and normal regions which werestrengthened visibly when examined by CEUS.3. The sensibility of CEUS in grading diagnosis of renal injury was higher than that of conventional ultrasound, especially in diagnosis of grade Ⅲ～Ⅳinjury (P＜0.05). The specificity of CEUS in grading diagnosis of renal injurywas higher than that of conventional ultrasound, but there was no significantdifference except grade Ⅱ injury (P＞0.05). The accuracy of CEUS in gradingdiagnosis of renal injury was higher than that of conventional ultrasound exceptgrade Ⅴ injury (P＜0.01or0.05).4. The consistency of CEUS with pathology in grading diagnosis of renalinjury (Kappa=0.740) was much better than that of conventional ultrasound(Kappa=0.354).5. The detectable rate of CEUS, conventional ultrasound for demonstratingrenal capsular laceration were81.4%(35/43),65.1%(28/43)(P＜0.05).6. The expression levels of HGF and TGF-β1in trauma group were bothhigher than that in control group (P＜0.005）and both increased while injuryincreased (P＜0.005）. The expression levels of HGF were higher than that ofTGF-β1（P＜0.05）.Conclusions:1. The animal models of blunt renal injury could be successfullyestablished by weight falling down to the renal region by using self-mademiniature impactor. The animal models were simple in operation and had goodrepeatability. The impact locations were accurate. The pathological types anddamage characteristics of the animal models were similar to that of clinicalpatients.2. The grading diagnosis of renal injury could be made effectively, quickly,easily and non-invasively when examined by CEUS. The echo of normal regioncould be strengthened visibly by using the second generation ultrasound contrastagent (SonoVue) and Contrast pulse sequencing imaging (CPS), so as to show the location, range and degree of injury and improve the sensitivity, specificityand accuracy of ultrasound in grading diagnosis of renal injury.3. The expression levels of HGF and TGF-β1in trauma group were bothhigher than that in control group and both increased while injury increased,however, the expression level of HGF was higher than that of TGF-β1. It isshowed that the changes of HGF and TGF-β1in kidney after injury are bothimportant to renal repair. The expression of TGF-β1could be inhibited when theexpression level of HGF increases, thus indicating HGF is strongly consideredas potential treatment for renal injury.