MRI screening for silicone breast implant rupture: accuracy, inter- and intraobserver variability using explantation results as reference standard.

OBJECTIVES

The recall of Poly Implant Prothèse (PIP) silicone breast implants in 2010 resulted in large numbers of asymptomatic women with implants who underwent magnetic resonance imaging (MRI) screening. This study's aim was to assess the accuracy and interobserver variability of MRI screening in the detection of rupture and extracapsular silicone leakage.

METHODS

A prospective study included 107 women with 214 PIP implants who underwent explantation preceded by MRI. In 2013, two radiologists blinded for previous MRI findings or outcome at surgery, independently re-evaluated all MRI examinations. A structured protocol described the MRI findings. The ex vivo findings served as reference standard.

RESULTS

In 208 of the 214 explanted prostheses, radiologists agreed independently about the condition of the implants. In five of the six cases they disagreed (2.6 %), but subsequently reached consensus. A sensitivity of 93 %, specificity of 93 %, positive predictive value of 77 % and negative predictive value of 98 % was found. The interobserver agreement was excellent (kappa value of 0.92).

CONCLUSIONS

MRI has a high accuracy in diagnosing rupture in silicone breast implants. Considering the high kappa value of interobserver agreement, MRI appears to be a consistent diagnostic test. A simple, uniform classification, may improve communication between radiologist and plastic surgeon.

KEY POINTS

MRI has a high accuracy in diagnosing rupture in silicone breast implants. MRI appears to be a consistent diagnostic test with excellent interobserver agreement. A simple, uniform classification system, improves communication between radiologist and plastic surgeon. The interobserver agreement on implant rupture is higher than on extracapsular leakage.