Magnetic Resonance IVIM-DWI Evaluation Of Preventive Effect Of Intravenous Hydration On Rabbit Injury Induced By Iodine Contrast Agent

Objective: With the maturity of multiple imaging modes such as CT enhancement and interventional diagnosis and treatment technology,the importance of contrast agent(CA)in clinical work is self-evident,but the acute induction after iodine contrast agent injection Post-contrast acute kidney injury(PC-AKI)is an urgent problem to be solved in clinical practice.PC-AKI is a serious complication after the application of iodine contrast agent,and is the second leading cause of drug-induced renal injury.It ranks third in hospital-acquired acute renal failure,promotes the progression of chronic kidney disease and increases patient mortality.risk.There is a greater risk of pre-existing chronic kidney disease and PC-AKI during dehydration.There is currently no effective treatment in the clinic,and the core measure is prevention.Intravenous hydration therapy has become the consensus of clinical prevention of PC-AKI,but the effect of intravenous hydration before injection of contrast agent and intravenous hydration after contrast agent injection is still inconclusive.Functional magnetic resonance is a special and effective non-invasive examination technique.It has good soft tissue resolution,high time and spatial resolution,and can track signal changes in real time.It has been widely used in the examination of kidney diseases.Magnetic resonance imaging(fMRI)Intravoxel incoherent motion(IVIM)diffusion-weighted imaging(DWI)can quantify both water molecule diffusion and microcirculation perfusion in voxels,and Distinguish them.This study mainly used IVIM-DWI to evaluate the preventive effect of intravenous hydration before injection of contrast agent and intravenous hydration after injection of contrast agent on rabbit kidney injury induced by iodine contrast agent,and pathological HE staining and immunohistochemistry APQ1 verification.To provide a theoretical basis for the prevention of the occurrence and development of PC-AKI.Methods: In this experiment,36 healthy male rabbits were randomly divided into 4groups: injection of the same amount of normal saline(n=9);intravenous hydration 3h before the injection of iodine contrast agent;intravenous hydration 3h after the injection of iodine contrast agent(n = 9);injection of the same amount of iodine contrast agent(n= 9).Rabbits were subjected to renal IVIM-DWI scan at 3h,24 h,and 72 h after injectionof saline or iodine contrast agent.According to the 1gI/kg standard,the iodine contrast agent was intravenously infused with normal saline(0.9% NaCl)through the rabbit ear margin for 3 hours,and the flow rate was 4 mL/kg/h.The DIM value,D* value and f value of the IVIM-DWI parameters on the right kidney crown image were measured at the ADW4.4 workstation,and the water molecule diffusion and microcirculation perfusion were observed.After the end of each group of scans,3 rabbits were randomly sacrificed at the corresponding time points.The right kidney was taken for pathological HE staining and immunohistochemical APQ1 examination to analyze the pathophysiological changes of the kidney.Results: Compared with group A,group B,group C,group D renal cortex,medullary parameter value D value,D* The value and the f-value pseudo-color map gradually appear to be cold,and the diffusion of water molecules and the restriction of blood perfusion are gradually aggravated.The renal skin,medullary D value,D* value and f value of the contrast agent were decreased 3 h before the contrast agent was injected.The D value of the group B(5.91±0.66)×10-4 mm2/s and the medullary D value(5.35)±0.82)×10-4 mm2/s and the corresponding group C cortical D value(4.90±0.93)×10-4mm2/s and medullary D value(4.29±0.73)×10-4 mm2/s statistically significant difference(P<0.05),the D value,D* value and f value of the renal cortex were reduced to the lowest at 24 h,and the D value of the B group(5.62±0.65)×10-4 mm2/s and D*value(7.86±0.48)× 10-3 mm2/s,f value(40.2±4)% and group C cortical D value(4.55±0.68)×10-4 mm2/s,D* value(6.82±0.40)×10-3 mm2/s,There was a statistical difference in f value(30.3±4)%(P<0.05),72 h renal cortex D value,D* value,f value showed a rising trend,medulla D value,D* value,f value decreased to the lowest,B Group medullary D value(5.09±0.21)×10-4 mm2/s,D* value(7.37±0.77)×10-3 mm2/s,f value(34.1±5)% and group C medullary D value(4.01±0.58)×10-4 mm2/s,D* value(6.27±0.47)×10-3 mm2/s,f value(25.7±3)% value was statistically significant(P<0.05).The pathological sections were observed under the microscope.Compared with group A,group B,group C and group D showed different degrees of glomerular and tubular opacity,swelling,degeneration,collecting duct type and interstitial hyperemia.The pathological damage was the heaviest,and the pathological damage was the lightest in group B.At the same time,immunohistochemical aquaporin 1(APQ1)increased theexpression in group D,and the expression in group B increased the least.Conclusion: Magnetic resonance IVIM-DWI technology can accurately monitor the occurrence and development of iodine contrast agent renal injury,and can effectively evaluate the protective effect of intravenous hydration before and after injection of iodine contrast agent on rabbit kidney injury caused by iodine contrast agent.Intravenous hydration before and after injection of iodine contrast agent can alleviate the damage of iodine contrast agent to a certain extent,and the hydration effect is better before the injection of iodine contrast agent.