Differentiating Benign from Malignant Adnexal Masses: Comparison of Two-Dimensional and Three-Dimensional Ultrasound Imaging

Abstract

This is a prospective study to compare two-dimensional (2D) and three-dimensional (3D) ultrasounds in differentiation of benign from malignant adnexal masses with histopathology as the gold standard. In this study, we performed 2D and 3D US on 94 adnexal masses from 76 women prior to surgery. Two radiologists independently analysed the 2D and 3D US images to differentiate benign from malignant adnexal lesions based on clinical judgment and ultrasound sassone scoring system. The inter-observer agreement and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for both the techniques. There were 82 benign (87 %) and 12 malignant lesions (13 %). The inter-observer agreement was substantial to almost perfect with kappa value ranging from 0.825 to 1. Compared to 2D and 3D US is more superior (p < 0.01) in the detection of wall thickness (49 % vs. 68 %), thick papillary projections (14 % vs. 43 %) and thick septations (43 % vs. 51 %). The sensitivity, specificity, PPV, NPV and accuracy were 92 %, 77 %, 36 %, 98 % and 78 %, respectively, for 2D US and 92 %, 61 %, 26 %, 98 % and 65 %, respectively, for 3D US. In conclusion, 3D US imaging is superior to 2D US in defining septal structures and papillary projection on the inner surface of the tumour. However, it does not have a better diagnostic accuracy than 2D US in the diagnosis of ovarian cancer.