Grating-based x-ray dark-field mammography: Assessing complementary imaging information in simple cystic lesions and typical fibroadenoma

Background: A significant proportion of false positive recalls of mammography-screened women is due to benign breast cysts and simple fibroadenomas. These lesions appear mammographically as smooth-shaped dense masses and require the recalling of women for a breast ultrasound to obtain complementary imaging information. They can be identified safely by ultrasound with no need for further assessment or treatment. Purpose: Grating-based x-ray dark-field breast imaging allows contrast formation based on both attenuation and small-angle x-ray scattering and provides complementary imaging information in one single acquisition. Methods: Experiments with ex-vivo mastectomy samples were performed with a three-grating Talbot-Lau interferometer using a laboratory-based polychromatic x-ray source. Attenuation and dark-field images were correlated to clinical mammography and complementary diagnostic imaging techniques. Results: Benign breast lesions with homogeneous internal structures such as fibroadenomas and simple fluid-filled cysts, typically presenting as dense breast lesions in standard mammography, showed a signal drop in the dark-field image. Complicated cysts provided a higher dark-field signal. Conclusions: The results presented show that grating-based x-ray dark-field mammography could provide complementary imaging information in one single acquisition, eliminating the need for a second examination to identify harmless cysts and simple fibroadenomas.