Application of Real-time Ultrasound Elastography for Discrimination of Low- and High-grade Serous Ovarian Carcinoma

OBJECTIVES: The purpose of this study was to evaluate real-time qualitative ultrasound elastography as an adjunct to conventional sonography for discrimination of low- and high-grade serous ovarian carcinoma. METHODS: Eighty-six patients suspected of having serous ovarian cancer on the basis of clinical and biochemical evaluations underwent transvaginal and transabdominal sonography and then elastography and later underwent surgery. RESULTS: Histopathologic analysis revealed 64 serous ovarian carcinomas (74.4%): 39 (60.9%) high grade and 25 (39.1%) low grade. The mean elasticity score ± SD was statistically significantly higher for low-grade lesions (3.40 ± 0.76) than high-grade lesions (2.08 ± 0.58; P < .001). There was a trend for high-grade lesions to be less stiff than low-grade lesions due to rapidly developing necrosis; conversely, low-grade lesions developed relatively slowly so that their solid areas were stiffer and less elastic. The median elasticity score for low-grade lesions (based on a 4-point scale used to grade cervical lymph nodes) was 4 (stiffest), and the score for high-grade lesions was 2. When the score of 4 was used for diagnosis of low-grade carcinoma, elastography had 56.0% sensitivity, 100% specificity, a 100% positive predictive value, a 78.0% negative predictive value, and 82.8% accuracy. When the score of 2 was used for the diagnosis of high-grade carcinoma, elastography had 66.7% sensitivity, 84.0% specificity, an 86.7% positive predictive value, a 61.8% negative predictive value, and 73.4% accuracy. CONCLUSIONS: Our results suggest that ultrasound elastography could be helpful for discrimination of low- and high-grade serous ovarian carcinoma. Low-grade lesions are stiffer and not as elastic as high-grade lesions.