Assessment of ischaemia-reperfusion injury in the mice testis by using contrast ultrasound molecular imaging.

Timely diagnosis of ischaemia-reperfusion (IR)-induced injury after testicular torsion may be critical for saving reproductive function. The purpose of this study was to detect IR-induced injury, indicated by E-selectin overexpression, in murine testis using ultrasound molecular contrast imaging. Mice underwent 720° unilateral testicular torsion (ischaemia) followed by detorsion (reperfusion), and the control group (Sham-IR) was operated identically without extended ischaemia. In a separate positive control group, TNF-α was injected intratesticularly to induce inflammation and compared to intratesticular saline injection. Selectin-targeted or nontargeted ultrasound contrast microbubbles were injected intravenously, and two-dimensional (2D) real-time high-resolution ultrasound testicular imaging was performed after reperfusion or after TNF-α injection. Contrast intensity levels were significantly higher in the testis of the IR group as compared to the Sham-IR group after injection of targeted contrast microbubbles. Contrast intensities were similar between the IR and Sham-IR groups after injection of nontargeted microbubbles. In addition, targeted contrast intensity levels were significantly higher in the TNF-α-treated group as compared to the control group. This study indicates that ultrasound contrast molecular imaging with microbubbles targeted to E-selectin can be used to assess IR-induced testicular injury.