Evaluation of the effect of silicone breast inserts on X-ray mammography and breast tomosynthesis images: A Monte Carlo simulation study

Purpose: Breast augmentation is one of the most popular cosmetic surgeries worldwide. The aim of this study is to investigate the effect of breast implant insertion on the detectability and visibility of lesions on mammography and breast tomosynthesis (BT) images. Materials and methods: Three software phantoms, composed of a homogeneous background with embedded silicone gel structures, and two types of breast abnormalities, microcalcifications (mu Cs) and masses, were generated. Two X-ray breast imaging modalities were simulated: mammography and BT with six incident monochromatic X-ray beams with energies in the interval between 20 and 30 keV. Projection images were generated using an in-house developed Monte Carlo simulator. The detectability of mammographic findings adjacent to the implant material and the influence of the incident beam energy and implant thickness on the feature detection were studied. Results: It was found that implants thicker than 26 mm for the case of mammography and 14 mm for the case of BT obscured the visibility of underlying structures. Although BT demonstrated a lack of contrast, this modality was able to visualize mu Cs under considerable depths of implant. Increasing the incident beam energy led to better visualization of small mu Cs, while in the case of breast masses, their detectability was limited. Conclusions: Silicone gel implants introduce a limitation in the image quality of mammograms resulting in low detectability of features. In addition, silicone gel implants obscure partially or totally parts of the image, depending on the size and the thickness of the implant as well the energy of the X-rays used. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.