Breast implant classification with MR imaging correlation: (CME available on RSNA link)

Rupture is now recognized as an important and common complication of breast implants. Magnetic resonance (MR) imaging is the most accurate method for evaluating implant integrity but requires an understanding of the numerous variations in implant construction that are encountered clinically. To assist in diagnosis, the authors provide an MR-oriented breast implant classification scheme based on data from 4,014 patients (>9,966 current or previous implants), the literature, and other primary documentation. This scheme consists of 14 implant types: 1) single-lumen silicone gel-filled, 2) single-lumen gel-saline adjustable, 3) single-lumen saline-, dextran-, or polyvinyl pyrrolodone-filled, 4) standard double-lumen, 5) reverse double-lumen, 6) reverse-adjustable double-lumen, 7) gel-gel double-lumen, 8) triple-lumen, 9) Cavon "cast gel", 10) custom, 11) solid pectus, 12) sponge (simple or compound), 13) sponge (adjustable), and 14) other. The MR imaging and mammographic appearance of many implant types is correlated with their actual appearance after explantation. A brief history of prosthetic breast augmentation and reconstruction is also provided to allow this classification method to be placed in historical perspective. Knowledge of the variety of breast implant types will help reduce misdiagnoses by providing imagers with better understanding of the expected appearances of breast implants. This classification scheme will allow stratification of data for studying incidence, prevalence, and risk factors for and causes of implant failure, as well as permitting better correlation with patient symptoms and surgical outcome.