Breast-specific gamma imaging or ultrasonography as adjunct imaging diagnostics in women with mammographically dense breasts.

BACKGROUND Mammography (MMG) shows decreased diagnostic accuracy in dense breast tissue, and thus, ultrasonography (US) and breast-specific gamma imaging (BSGI) have gradually been adopted for women with mammographically dense breasts. However, these two adjunct modalities have not been directly compared in previous studies. Hence, we investigated the adjunctive efficacy of US and BSGI in mammographically dense breasts. METHODS This retrospective, comparative study recruited women with mammographically dense breasts. All enrolled women underwent US and BSGI as adjunctive imaging, and the comparative sensitivity, specificity, and diagnostic accuracy of combined MMG plus BSGI versus MMG plus US were evaluated. McNemar's test was used for paired binary data in this comparative analysis. RESULTS From April 2013 to April 2016, 364 women with mammographically dense breasts and a final surgical or biopsy pathological diagnosis were recruited, comprising 218 cases of malignant disease (59.9%) and 146 cases of benign disease (40.1%). There was no difference between BSGI and US in enhancing the sensitivity of MMG diagnosis (Se-Difference 3.2%, p = 0.23), but the diagnostic specificity of MMG plus BSGI was superior to that of MMG plus US (Sp-Difference 10.3%, p = 0.003). The area under the ROC curve showed that MMG plus BSGI had better diagnostic accuracy than MMG plus US (0.90 vs. 0.83, p = 0.0019). CONCLUSIONS For women with mammographically dense breasts, MMG plus BSGI or US can improve the diagnostic accuracy. In addition, BSGI has high specificity and could reduce invasive biopsies and thus may represent a viable diagnostic imaging alternative for mammographically dense breasts. KEY POINTS • Both BSGI and US can be applied as adjunct imaging diagnostics in women with mammographically dense breasts. • The diagnostic accuracy of MMG plus BSGI was higher than that of MMG plus US. • BSGI has the potential to be used as an adjunct diagnostic modality in women with mammographically dense breasts.