Experimental Study On Shear Wave Elastography To Evaluate Acute Testicular Torsion Injury

Objective To evaluate acute testicular torsion injury with the use of Real-time Shear Wave Elastography(SWE),Contrast-enhanced Ultrasound(CEUS)and quantitative analysis techniques.Research on the clinical value of SWE in testicular torsion diagnose and explore a noninvasive and objective method evaluate the testicular ischemic injury.Methods To prepare the general lipid microbubbles(MB)and detect its physical property and correlative performance.A total of 30 healthy audlt rabbits were randomly divided into 3 groups including control groups(Group S),complete torsion group(Group C)and incomplete torsion group(Group U)with 10 in each group.Group S were randomly dissected to expose one side of rabbits' spermatic cord and threaded without torsion.Group C were randomly dissected to expose one side of rabbits' spermatic cord and threaded with detection under color ultrasound until testicular blood flow signals disappeared completely for building a completely testicular torsion model of operation side.Group U were randomly dissected to expose one side of rabbits' spermatic cord and threaded with detection under color ultrasound until testicular blood flow signals disappeared to half of pre-operation for building a uncompletely testicular torsion model of operation side.Rabbits in each group were performed with 2-D ultrasound,color doppler flow imaging and SWE examination before and after 6-hours operation,followed by observing the changes of ultrasonogram and recording Emean value of testicular capsule,parenchyma testis,spermatic code torsion section and next torsion section.Meanwhile,rabbits in each group were performed with MB before and after operation,followed by analyzing the changes of contrast parameters of each group with the ultrasound contrast quantitative analysis technologies including PI,TP,Slope,MTT,DT/2,to obtain accurate and dynamitic testicular blood perfusion information.HE staining and immunohistochemistry staining were performed on the testis of the operation side after operation for observation of the pathological changes.Results 1.Correlative detection of lipid microbubble: MB was milky white turbid liquid by naked-eye observing and roundness under light microscope,the distribution and particle size of the microbubble was uniform.After 30 minutes' standing at room temperature,the number of microbubbles reduced and the particle size of the microbubble became nonuniform.In addition,after one day's standing at room temperature the number of microbubbles became sparse and the particle size of the microbubble was small.The concentration of the microbubble was 4.8×108/ml approximately.2.Expression of SWE: Preoperative SWE were similar between each group.There was no significant difference in Emean in relative parts(P>0.05).There was some difference in postoperative Emean between each group(P<0.05).Postoperative SWE was similar with that of preoperative and there was no statistical significance for Emean of relative parts(P>0.05).(1)Expression of SWE in testicular capsule: Postoperative Emean of testicular capsule of operation side in group C rose slowly as time went on.Curve yellow green or red yellow signals appeared gradually in testicular capsule.Postoperative Emean of testicular capsule of operation side in group U rose rapidly within 1.5 hours and became steadily after that.Yellow or red hard ring signs appeared in testicular capsule.(2)Expression of SWE in parenchyma testis: Postoperative Emean of parenchyma testis of operation side in group C and U rose slowly.There was no obvious changes for color of parenchyma testis,it was blue always.(3)Expression of SWE in spermatic cord torsion section: Postoperative Emean in spermatic cord torsion section of operation side in group C rose rapidly and immediately and kept rising obviously with time went on after spermatic cord torsion,color of which became dark yellow and became hard with a large patch of red signalsappeared obviously with time passed.Postoperative Emean in spermatic cord torsion section of operation side in group U rose immediately and kept rising steadily after spermatic cord torsion,color of which became light green and became hard slowly with a few red signals appeared with time passed.(4)Expression of SWE in spermatic cord torsion next section: Postoperative Emean in spermatic cord torsion next section of operation side in group C was on the rise with time passed.SWE showed that spermatic cord of next torsion section became hard,color of which became green from original blue.Otherwise postoperative Emean in group U was on the rise with time passed.SWE showed that spermatic cord of next torsion section became light hard,color of which became blue green from original blue.3.Expression of CEUS: Preoperative CEUS of each group were similar.There was no statistical significant for parameters of CEUS among each group(P>0.05).TIC were roughly the same.There was also no significant difference in postoperative parameters of CEUS in group S(P>0.05).(1)Postoperative contrast agent was not filling in testicular of operation side in group C.TIC curve was flat and seemed as a straight line,area under the curve was zero.(2)Postoperative contrast agent was filling slowly in testicular of operation side in group U and the PI was low,it became “slow forward and slow backward”.PI and Slope of Parameters of CEUS reduced,TP,MTT and DT/2 were extended.AUC was reduced.The difference was became more obvious with time passed.TIC curve was moved and PI was flatly low.4.Pathological feature: The testicular spermatogenic cells in group S were in alignment with clear lumen.The testicular microvascular structure of interstitial substance was clear without expansion of microvascular lumen,interstitial edema,erythrocyte leakage and inflammatory cell infiltration.The testicular spermatogenic cells in group C were in disorder with exfoliated dead cells in lumen.The microvascular of testicular interstitial substance and cupsule developed lightly with expansion and congestion of lumen,leukocytes surrounding,interstitial edema,erythrocyte leakage and inflammatory cell infiltration.The testicular spermatogenic cells in group U were in disorder without exfoliated dead cells in lumen.The microvascular of testicular interstitial substance and cupsule developed turgidly with expansion and inflection and congestion of lumen,leukocytes surrounding,microthrombus formed in lumen.Parts of walls were broken with inflammatory cells adhesion and surrounding,interstitial edema and a patch of erythrocyte leakage and inflammatory cell infiltration.Conclusions 1.SWE showed the change of spermatic cord and testicular after spermatic cord torsion were related with degree and time of torsion.The hardness changes of testicular capsule and spermatic cord torsion section are most obviously.2.The use SWE is effective in diagnose for acute testicular torsion and able to get hardness information of testicular and spermatic cord after spermatic cord torsion actually and objectively.