The Experimental Study Of Color Dopper Ultrasound Diagnosis In Incomplete Testicular Torsion

Objective: To improve early diagnosis of initial testicular torsionthrough the observation of Color Doppler ultrasonic(CDU) image andpathological change of experimental incomplete testicular torsion atdifferent stage in 24 hours.Methods: Experimental models of incomplete testicular torsion wereestablished in six dogs. CDU image of testis and spermatic cord wascontinually observed after torsion for 24 hours through the probe of 7～14MHz ,with the observation interval of 2 hours in the first 6 hours,and 3 hours afterward. The grayscale image and Color Doppler Flow Image(CDFI),Color Doppler Energy(CDE) and Doppler Waveform of testis andevery segment of spermatic cord were observed and recorded at differentstages after torsion. Compared CDFI with CDE of testicular flow throughimage analysis software. The testis Tru-Cut biopsy was performed by 18Gneedle at 6,12,24 hours after torsion to survey the change of testicularultramicrostructure by electron microscope . Light microscope study oftesticular tissue had been carried out to observe the degreed ofhaemorrhage and necrosis after 24 hours of torsion. CDU image of testiswas investigated and compared with pathology results of testicular biopsyat corresponding stages.Results: Before torsion ,the resistance index of testicular arteryat spermatic cord, subtunic and intratestis were(0.65±0.04),(0.45±0.03)and (0.40±0.03) respectively. After torsion, the resistance index oftesticular artery above the twisted segment was significantly increased(P<0.05),and the spectral waveform of diastolic reversal can be seen insome cases. The resistance index of testicular artery below the twisted,capsular artery and intratesticular artery were significantlydecreased(P<0.05), resulting in nonpulsatile flow. There were nosignificant blood flow display between PDI and CDFI in the first 6 hours(P>0.05) ,and we found a significant different after 6 hours it wasrotated(P<0.05). The volume of testis after torsion(11.24±1.53)cm3was significantly increased compared with that before torsion(7.07±0.68)cm3 (P<0.05). With the torsion prolonging ,the intratesticular bloodflow was reduced gradually till absence. The intratesticular blood flowdisappeared in 6～18h after torsion,average(10±3.69)h. Echogenicityof testis became unhomogeneous at the stage which intratesticular bloodflow disappeared. Pathology results showed that in 6 hours the mainchanges of testicular tissue were edema, in 6～18 hours the main changeswere ecchymosis,hemorrhage and various degeneration, and in 18～24 hoursa majority of testicular tissue were necrosis . It revealed there werelesions of different level in testis at different stages.Conclusion: This investigation displayed the dynamic image of CDU andpathologic change of incomplete testicular torsion in 24 hours anddemonstrated its haemodynamics changes and pathologic bases and it canprovide experimental evidences to diagnose initial testicular torsion inclinic.