Real-Time Gray-scale Ultrasound Contrast Imaging In Evaluation Of Renal Blood Perfusion Of Acute Renal Failure In Rabbit: Experimental Study

Objective: Using real-time contrast tuned imaging( CnTI)with time-intensity curve(TIC) to quantify changes of the cortical and medullary perfusion of the kidney in rabbits at different time points after acute renal failure(ARF),compared with the pathological changes and serum creatinine(Scr),blood urea nitrogen(BUN).Methods: Fifteen healthy male rabbits were prohibited drinking water for 24 hours, then injected 50% glycerol into the hind leg intramuscularly to establish ARF models. Renal functiontests such as Scr and BUN were examined before glycerol injection and 30minute, hours 6,24,48,72 after glycerol injection. At each time point measured the left kidney and cortex thickness by 2D ultrasonography,then investigated blood perfusion of the left kidney with contrast tuned imaging and stored the dynamic contrast imaging,after that one rabbit was killed randomly at each time point and its kidney was sampled for pathological examination. At last quantified the blood perfusion by time-intensity curve quantitative analyzing software(Wash in/ Wash out), parameters include:peak signal intensity,area under the curve, ascending slope rate, time to peak intensity,time to enhancement. Using pathology and blood tests as reference,to compare the changes of blood perfusion and TIC parameters in ARF rabbits at different time points.Results: decreased cortical perfusion was found at each time point, showen by decrease of peak signal intensity and area under the curve,but at 48hours and 72h the two parameters had the increasing tendency,higher than that of 24h Since 24h scending slope rate decreaced and time to peak delayed. Medullary area under the curve, peak intensity increased since 24h,48h respectively. Changes of morphous of the kidneys were found by 2D ultrasonography since 24h,at the same time point typical pathological tubule necrosis appeared,and at 48h,72h pathological changes appeared more serious.Conclusions:1. Contrast enhanced ulrsound combined with time-intensity curve can quatify renal perfusion of ARF at different stage.2.The haemodynamic changes of ARF in rabbits occurred earlier than that of Scr and BUN.3.The tendency of the changes of cortical perfusion was imcompatible with that of laborary tests and pathology in the progression of ARF.