Contrast-enhanced ultrasonography using Sonazoid® is useful for diagnosis of malignant ovarian tumors: Comparison with Doppler ultrasound

Purpose: The purpose of this study was to assess the usefulness of Sonazoid®-enhanced ultrasonography (US) in the diagnosis of ovarian cancer in comparison with Doppler US. Methods: Twenty-five ovarian tumor patients who were scheduled to undergo surgery were recruited for this study. The day before the operation, each patient was evaluated with color and power Doppler and baseline US during intravenous infusion of Sonazoid. Each lesion was classified as "benign" or "malignant" on the basis of specific criteria for a Doppler signal or Sonazoid-enhanced pattern. The reference standard was the histology of surgically removed adnexal tumors. Results: Twenty patients were diagnosed with malignant tumors (invasive cancer, n = 15; metastatic cancer, n = 1; borderline tumor, n = 4), and the remaining five were diagnosed with benign tumors. Sonazoid-enhanced US correctly depicted the presence or absence of intratumoral blood flow in all patients with an accuracy of 92 %. Color Doppler ultrasound depicted the malignancies with an accuracy of 64 %, and power Doppler ultrasound depicted them with an accuracy of 76 %. Conclusion: Our study suggests that Sonazoid-enhanced US is superior to conventional color Doppler US for the diagnosis of malignant ovarian tumors, but not to power Doppler US. The data and their interpretation in our study should be taken with some degree of caution because of the small number of subjects. Further studies involving a larger sample size would be needed to confirm these findings.