Image Analysis of Breast Reconstruction with Silicone Gel Implant

The successful use of silicone gel implants and their acceptance from the medical community and the increased number of surgeries for breast reconstruction, necessitate a close examination of their effects in mammographic image quality. The insertion of silicone gel implants, because of their higher atomic numbers and attenuation coefficient compared with breast tissue, obscure a large area of the image acquired. Such an effect can reduce the ability of early detection of breast cancer. The objective of this work is to examine the effects which come along with a silicone gel insertion in the detection of cancer lesions using mammography. The study was performed with three software phantoms with breast equivalent tissue and silicone gel material, using Monte Carlo X-ray imaging simulations. From the images acquired the Contrast to Noise Ratio (CNR) of the main mammographic findings has been analyzed. Furthermore, the effect of increasing the incident beam energy, as well as the implant thickness on the visibility of breast lesions and the image quality of the complete mammogram have been studied. Results showed a major reduction of visibility in the area of the implant and adjacent to it as well as a reduction of CNR values of about 50%.