Interreader variability and predictive value of US descriptions of solid breast masses: Pilot study

Rationale and Objectives. This study evaluated the specificity of ultrasoun d (US) characteristics of solid breast lesions and the interreader variabil ity in their interpretation. Materials and Methods. In 61 patients, 70 sonographically visible solid mas ses, scheduled for biopsy because of findings from conventional imaging, we re prospectively and sequentially accrued for evaluation. Three readers int erpreted the sonograms and described the solid masses in terms of establish ed US characteristics. The specificity and positive predictive value (PPV) for each characteristic were calculated by comparing US findings with biops y findings, and interreader variability was evaluated. Five assessment cate gories were developed to guide recommendations for patient care. The relati ve performance of each reader was assessed by measuring the PPV for each as sessment category and by measuring the area under the receiver operating ch aracteristic curve. Results. The specificity and PPV were calculated for all characteristics an d for each reader. The average specificities of the three readers for the m ost frequently used six characteristics were as follows: spiculation. 97% /- 5 (standard deviation); taller than wide, 91% +/- 4; central shadowing, 77% +/- 1; markedly hypoechoic, 86% +/- 5: duct extension, 95% +/- 5; and m icrolobulation, 84% +/- 3 (overall average specificity, 88.5%). The average PPVs for categories II-V were 54%, 10%, 63%, and 94%, respectively. The re aders' interpretations were similar and correlated well. Conclusion, The proposed US recommendation system is an accurate predictor of histologic findings. A sonographic classification lexicon should prove v aluable.