The relative radiolucencies of breast implant filler materials

Breast implants in current use utilize silicone gel for filler material. One substantial drawback of silicone gel is its radiodensity, resulting in the obscuration of breast tissue on mammography. The relative radiolucencies of silicone gel, saline, breast tissue equivalent, triglycerides (peanut oil), and polyvinylpyrrolidone (Bio-Oncotic gel) were determined by using standard mammographic equipment. Visibility through these materials was compared by using a standard breast phantom as background. The x-ray dosage necessary to create each mammographic image was measured. Peanut oil provided the clearest image of the phantom artifacts, required the least radiation exposure, and was approximately four times more radiolucent than the saline or Bio-Oncotic gel and about 45 times more radiolucent than silicone gel. As improved implant filler materials are being sought, triglycerides maintain superior radiographic properties.