Role of US in evaluating breast implant integrity.

PURPOSE: To assess the diagnostic accuracy and inter-observer variability of ultrasound (US) in recognizing signs of intra or extra-capsular rupture of silicone breast implants by using the magnetic resonance imaging (MRI) findings as the reference standard.
METHODS: 150 patients for a total of 300 implants underwent breast US and subsequently MR examination searching for signs of intra or extra-capsular rupture. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for breast US having MRI findings as the reference standard. Cohen's kappa statistics was used in order to assess inter-observer agreement for US.
RESULTS: 170/300 (57 %) implant ruptures were detected at US (intra-capsular n = 110, extra-capsular n = 60). By comparing US findings with MR results, overall sensitivity, specificity, accuracy, PPV, and NPV of 79, 63, 70, 65, and 77 %, respectively, were found for breast US. In case of intra-capsular rupture, sensitivity, specificity, accuracy, PPV, and NPV of 63, 63, 63, 45, and 77 %, respectively, were obtained; 100 % values were found for extra-capsular rupture US diagnosis.
CONCLUSION: US can be used as the first examination in patients with breast implants. US intra-capsular rupture detection requires further evaluation by MRI; in case of extra-capsular rupture US diagnosis, surgical implant removal could be proposed without further investigations.