Sonographic signs of breast implant rupture.

OBJECTIVE

This study evaluated sonography as a screening test for breast implant rupture and developed diagnostic criteria for implant rupture.

SUBJECTS AND METHODS

Women contemplating implant removal were evaluated prospectively with sonography. Implants were classified as normal, indeterminate, or ruptured. Individual sonographic signs were analyzed for their statistic association with implant rupture. To measure the degree of interobserver variation, static images were evaluated by two different observers.

RESULTS

Of 236 implants evaluated, surgical confirmation was available in 78, 22 of which were ruptured and 56, intact. Echogenic noise, multiple discontinuous parallel linear echoes, and echodense aggregates in the implant lumen were statistically associated with rupture. Based on sonographic findings, we classified 34 implants as intact (at surgery: 31 intact, 3 ruptured). We classified 19 as ruptured (at surgery: 11 ruptured, 8 intact). Of the 25 implants we classified as indeterminate, 17 were intact and 8 were ruptured at surgery. Therefore, sonography had a positive predictive value of 58%, a negative predictive value of 91%, a sensitivity of 50%, and a specificity of 55%. Receiver operating characteristic analysis suggests a learning curve effect and no significant interobserver variation.

CONCLUSIONS

A normal sonographic result is highly predictive of an intact implant. Thus, sonography is useful in evaluating symptomatic women or women concerned about implant rupture. An indeterminate sonographic result suggests the need for further testing.