To Evaluate The Early Changes Of Renal Ischemia-reperfusion By Susceptibility Weighted Imaging

Objective:To establish the renal ischemia-reperfusion (IRI) model of rabbit for explore whethersusceptibility weighted imaging (SWI) could diagnose the early changes of RenalIRI.Material and Methods:Twenty four New Zealand white rabbits with the similar weight, the left kidney of therabbit was ligated for60min, then the renal ischemia-reperfusion model was established,Respectively, the living rabbits before ligation,0.5h,24h and48h after the ligation, wereexamined by the T2WI and SWI, after that the rabbit was immediately put to death, thespecimen in vitro were submerged to the0.9%saline for the MR scanning, at last toanalyze the signal changes of the of cortex and medulla of the IRI-renal by the SWI,andcheck the number of small vessel in the outer medullary of the specimen, comparing theimaging features with histopathology.Results:The inner medullary of renal showed high signal in T2WI, low signal in the outermedulla and mildly high in the cortex before ligation, which showed the tipicallythree-band signal distribution,while outer medulla showed wildly hyper-signal in SWI, theremnants showed high signal; kidney swelled significantly0.5hour after ligation, the stripeof cortex became thin, however, the inner medulla and outer medulla widened. Thehypo-signal of the outer medulla faded, while the signal of inner medullary and corticalslightly elevated. The signal of outer medulla reduced more obviously in SWI，the marginof the cortex and medulla became clear24h and48h after ligation, However the signal ofthe outer medulla was still higher than normal in the SWI, and punctate,stripe haemorrhageoccurred in the out medulla. The number of haemorrhage in the outer stripe of the medullawas respectively0，2.5，6.75（P＜0.001）,Respectively the number of small vessels in theout medulla in the experimental kidney and contralateral in vitro0.5h,24h and48h afterligation were10.2,20.75;8.6,21.13;4.5,20.88（P＜0.001）. Conclusion:SWI can clearly show early changes in IRI-renal,especially outer medulla of the renal,the change of the number of vascular changes in the specimen in vitro can also beobserved,hence the technique can be used to assess changes in early changes of IRI ofrenal.