Contrast-enhanced ultrasonographic visualization of gonadal torsion

The purpose of this study was to investigate the effect of use of intravenous ultrasonographic contrast agent in the diagnosis of gonadal torsion in an animal model. After examination of perfusion of normal gonads in male and female dogs, torsion was produced and maintained mechanically. Presence and pattern of blood flow was then reassessed before and after administration of varying doses of perfluorocarbon-filled microsphere intravenous contrast agent. Modes of examination included gray scale, color flow, color power, and spectral analysis using a transducer placed directly on the surgically exposed gonads. Although no enhancement was perceptible on gray scale images, color and spectral Doppler signals were significantly stronger after injection of contrast agent in both normal and rotated gonads. Perfusion asymmetry was more obvious. Some residual flow was seen in partially rotated testes, and absence of flow was documented in both partially and fully rotated ovaries. Use of intravenous contrast medium improves demonstration of altered flow patterns in ischemic gonads, allowing more confident diagnosis.