Preliminary Study Of The Acoustic Radiation Force Impulse Image Technology In Diagnosis And Treatment Of IgA Nephropathy

Objective:1To investigate the application value of ARFI （AcousticRadiation Force Impulse）on quantitative evaluating the elastic change ofrenal cortex in various pathological indexes of the Oxford classification.2Toassess the correlation between Vs of renal cortex, renal medulla and Scr,BUN by using of ARFI to measure the renal elasticity and to obtain the bestcritical value of Vs when the renal function was changed from normal toabnormal. Measure the Vs of renal cortex in different stages of venal function,so as to estimate the level of the damage. Provide a new observation index forthe early diagnosis of renal function decreasing and clinical staging.Methods:117patients were chosen. They were diagnosed with IgAN (therenal function was abnormal.)And were all taken treatment during December2011to October2012. The control group has80normal cases. The SiemensACUSON S2000ultrasound imaging system equipped with VTQ technologysoftware was adopted.4C1convex array probe with2.0-2.4MHz frequencywas selected. The patients lay on the side. First use the two dimensionalgray-scale ultrasound to scan the long shaft section and the cross section.Measure the length, width and the thickness of the kidney. Observe the echoof the cortex, the medulla, the capsule and the inner structure. Then the bloodflow was observed by color Doppler, including maximum blood speed of theinterlobular arteries and the resistance index. At last, ARFI imagingtechnology software was adopted. We chose renal cortex, renal medulla andrenal collecting system as the regions of interest, directing acoustic beamperpendicular to the kidney surface. At least five samples were taken for eachdomain, and the mean was recorded as the Vs. The routine biochemistryresults and renal biopsy results were recorded. Results：1The Vs of renal parenchyma were higher than those in the abnormalgroup. While the Vs of collection system of both group was not statisticallydifferent.2The correlation analysis showed that the Vs of renal cortex, renalmedulla had negative correlation with Scar and BUN.3The critical value of Vs in renal cortex, renal medulla is2.7cm/s、2.35cm/s. The accuracy of the diagnosis is71%,64%respectively.Furthermore the accuracy of VTQ is higher than RI.4With the damaging of the kidney, the value of VTQ of the renal cortexdecrease in the order of1,2,3,4, and class5is larger than class4.5The Oxford classification of IgAN cannot be received by the VTQ ofthe renal cortex effectively, so it is no application value on classifying therenal disease. But the results show that T which can represent the renal tubularatrophy and interstitial fibrosis can be classified by the VTQ. There is fewdifferences between T0and T1，but big difference between T0,T1,T2. T2islarger than T1,ConclusionAFRI provide a novel uninvasive method for early diagnosis of renalimpairment. It’s better than Scr and BUN. Furthermore the sensitivity,specificity, accuracy are superior to Hemodynamic. Therefore, ARFI can beused as a new observation index to classify the degree of renal impairment.But the result show that it cannot be used to classify IgAN, so there is noobvious application value.