Experimental study on diagnostic value of shear wave elastography for acute testicular torsion injury / 中华超声影像学杂志

ABSTRACT

Objective:To investigate the value of real-time shear wave elastography (SWE) in the diagnosis of acute testicular torsion.Methods:A total of 30 rabbits were randomly divided into 3 groups including control group (Group S), complete torsion group (Group C) and incomplete torsion group (Group U), and corresponding animal models were built. Rabbits in each group were examined by gray scale and color Doppler ultrasound, SWE and contrast-enhanced ultrasound(CEUS) before and after operation. Mean values of elasticity modulus (Emean) of testicular capsule area, parenehyma testis, spermatic cord torsion section, torsion lower section and contrast-enhanced ultrasound parameters were recorded and then pathological examinations were performed.Results:There was no significant difference for Emean values of each group in all parts before operation( P>0.05). There was no significant difference for Emean value of S group at each period after operation( P>0.05). Emean value of postoperative testicular capsule area in U group increased obviously and rapidly compared with C group, yellow or red "hard ring signs" appeared within four to six hours after operation, there was significant difference of Emean value difference at various periods after operation in group U and C, and at 1 h, 1.5 h, 2 h, 2.5 h, 3 h and 3.5 h postoperatively between group U and C( P<0.05). Postoperative Emean value of parenchyma testis in group C and U increased about 5 kPa, expression of SWE was consistent blue. Postoperative Emean value of spermatic cord torsion section in group C increased more obviously compared with U group, a large patch of red signals appeared within five to six hours after operation, there was significant difference of Emean value at various periods after operation in group C and U, and at each period except instant, 2 h, and 3 h postoperatively between group C and U( P<0.05). Postoperative Emean value in spermatic cord torsion lower section in group U and C increased slowly ( P<0.05), expression of SWE changed from blue to blue green and green from original blue. CEUS showed blood pefusion in testis was "in and out slowly " in group U, pathological feature showed the testicular spermatogenic cells were in disorder with interstitial edema, distinct expansion of microvascular lumen, hyperemia and congestion and lots of erythrocyte leakage. CEUS showed postoperative contrast agent was not filling in testicular in group C, pathological feature showed the testicular spermatogenic cells were in disorder with interstitial edema, slight expansion of microvascular lumen, congestion and part erythrocyte leakage. Conclusions:The image changes of SWE after acute testicular torsion are related with the degree and time of torsion, the changes of testicular capsule area and spermatic cord torsion section are most significant. The use of SWE helps to get accurate hardness information of focus with effective clinical value for the diagnosis testicular torsion.