X-ray based breast imaging, specifically in the form of digital mammography and digital breast tomosynthesis, is well-established as the most common imaging method for detection and diagnosis of breast cancer. However, new and upcoming advances based on dedicated breast CT hold promise for not only improvement in cancer diagnosis, but also for x-ray imaging to have a crucial role in the introduction of precision medicine for breast cancer care. This will involve taking x-ray imaging to a 4^th dimension, with innovations in image acquisition, reconstruction, processing, filtering, and analysis. With these advances, x-ray breast imaging has the promise to revolutionize breast cancer treatment.