[Magnetic resonance imaging of breast implants. Significance compared to mammography and ultrasonography].

Magnetic resonance imaging (MRI), mammography and ultrasonography were performed in 44 consecutive women (mean age 45 [29-70] years) with a total of 73 silicone breast implants. The implant had been inserted after mastectomy for cancer in 15 patients, for cosmetic breast augmentation in 29. MRI proved to be superior to the other two imaging modalities with respect to assessing implant content, capsule and surrounding tissues. In 39 patients MRI clearly demarcated the implant from the residual breast tissue. But in four patients the lateral MRI assessment was impaired by phase artefact and in one other by movement artefacts in a restless patient. Implant thickness was underestimated by mammography and ultrasonography compared with MRI. In nine cases mammography showed retromammary parenchyma, while MRI did so in 20. The posterior wall of the implant was visualized by mammography in only one patient, but in all of them by MRI. Ultrasonography failed in all patients to show the entire implant circumference. In three cases MRI was the only imaging method which revealed a defect in the implant capsule with extrusion of silicone.