Contrast Enhanced Ultrasound in Assessment of Adnexal Masses

Abstract

Pelvic ultrasonography (US) remains the imaging modality most frequently used to detect and characterize adnexal masses. (Brown et al., 2010). Vascularity influences not only the characteristics of gynecologic tumors observed with direct imaging techniques (color and power Doppler), but it also has an impact during indirect imaging involving the administration of contrast agents to examine the microcirculation and interstitial perfusion. (Sconfienza et al., 2010). Contrast agents for ultrasonography (US) comprise microscopic bubbles of gas in an encapsulating shell, oscillating in response to a low-intensity ultrasound field and disrupting in response to a high-intensity field (Wilson and Burns, 2010). Blood-borne bubbles provide a distinct acoustic “label” for their identification that is independent of flow velocity (Burns, 2009). The most common general adverse events reported are the same as those seen with other types of contrast media (ter Haar, 2010). Clinical studies have not shown such adverse events and indicate that ultrasound contrast media are generally safe.(Jakobsen et al., 2010). Although most adnexal masses arise from the ovary, diagnostic errors will be made if one assumes an adnexal mass is of ovarian origin. (Madan, 2013). Sonographic Features of Malignant Ovarian Neoplasms are: Solid Component, Septa, and Ascites (Brown et al., 2010). Color Doppler US is best utilized in a qualitative mode to look for flow within a solid component or septum (Kinkel et al., 2011). CEUS can be proposed as a method capable of furnishing additional morphological information not obtainable with conventional ultrasound.(Sconfienza et al., 2010). Analysis of peak intensities and time/intensity curves revealed significant differences between benign and malignant lesions. CEUS improved diagnostic confidence in the diagnosis of lesions with liquid corpuscular structures, which is difficult with the conventional technique. CEUS proved to be particularly useful in hemorrhagic lesions (particularly hemorrhagic corpus luteum), hydrosalpinx, and solid lesions with pseudoliquid features. Use of this method could be an alternative to other contrast-enhanced techniques like CT or MRI for the differential diagnosis of a limited number of complex lesions (Sconfienza et al., 2010). Recent studies from several medical centers worldwide have shown that contrast enhanced transvaginal sonography (CE-TVS) can detect early stage ovarian cancer. (Fleischer et al., 2011).