Magnetic resonance evaluation of breast implants and soft-tissue silicone.

After several years of research in many disciplines, concern for the safety of silicone gel-filled breast implants continues. Although systemic effects of silicone are debated, there is growing consensus that implant rupture and other local breast complications from implants are very real concerns. This paper reviews the history of breast augmentation with an emphasis on the great variety of implants manufactured during the last generation. A classification scheme consisting of 14 breast implant categories is described, and the MR appearance of many is illustrated. The MR signs of implant rupture and pitfalls associated with those signs are reviewed. Indications and contraindications for MR imaging of implants and soft tissue silicone are presented. The author's breast implant and soft-tissue silicone MR imaging experience with follow-up surgical experience over the last 6 years is summarized and discussed. For 1,626 single lumen silicone gel-filled implants imaged, the sensitivity for rupture was 74% and the specificity was 98%. For those implants, 64.9% showed no evidence rupture on MR, 7.9% were indeterminate, and 27.2% were definitely ruptured. Of those that were ruptured, 26.2% had silicone outside as well as within the fibrous capsule. Of the 442 implants that were shown to be ruptured, 54.8% were in a state of uncollapsed rupture, 12.9% minimally collapsed rupture, 4.1% partially collapsed rupture, and 28.3% fully collapsed rupture.