Doppler contrast sonography for detecting reduced perfusion in experimental ischemia of prepubertal rabbit testes

Rational and objectives. We examined whether the intravenous (IV) Doppler ultrasound contrast agent SHU 508 would improve the detection of reduced perfusion of rabbit testes when normal flow was otherwise difficult to detect. Methods. Seventeen anesthetized prepubertal rabbits underwent random unilateral spermatic cord ligation and a contralateral sham operation. Immediate, blinded, and systematic color Doppler examination of each pair of testes was recorded before and after IV administration of 1 ml (300 mg) SHU 508, a gas-containing microparticle. Recorded examinations were reviewed by two pediatric radiologists who were unaware of experimental conditions and who graded intratesticular flow. Results. For 34 pairs of observations (17 animals x 2 observers), intratesticular flow was absent in the sham-operated testes in 18 precontrast and two postcontrast images. The false-positive rate in this group decreased from 53% to 6%. This improvement in the detection of normal blood flow was statistically significant. The absence of flow in the ischemic testis was not significantly different before or after contrast agent administration. Conclusion. IV SHU 508 enhances color Doppler ultrasound detection of flow not otherwise evident in prepubertal rabbit testes. Doppler ultra-sound contrast agents may be used in a setting of suspected torsion when routine Doppler sonography is indeterminate.