Diagnosis and Staging of Breast Cancer: When and How to Use Mammography, Tomosynthesis, Ultrasound, Contrast-Enhanced Mammography, and Magnetic Resonance Imaging

Breast cancer is the most cause of female cancer deaths in the western world, with early detection of cancer being pivotal for an improved prognosis and survival. Imaging plays a pivotal role in breast cancer detection and staging and helps guiding treatment decisions. Imaging modalities for diagnosis and staging of breast cancer comprise mammography, digital breast tomosynthesis (DBT), ultrasound, contrast-enhanced mammography (CEM), and magnetic resonance imaging (MRI). Mammography is the mainstay of breast cancer screening and diagnosis. Mammography, together with ultrasound and MRI, is used to detect and characterize lesions found at screening and to evaluate symptomatic women. In patients with breast cancer, mammography, often in conjunction with specialized views, can determine lesion size and location and assess the surrounding tissue and lymph nodes. DBT is a three-dimensional (3D) imaging method with the potential to overcome the main limitation of standard two-dimensional mammography, a masking effect due to overlapping fibroglandular breast tissue, improving diagnostic accuracy in breast cancer, particularly in dense breasts. CEM allows both a morphologic evaluation comparable to routine digital mammography and through contrast agent application a simultaneous assessment of tumor neovascularity as an indicator of malignancy similar to MRI. Data indicate that CEM has an improved sensitivity and increases the specificity compared with mammography. Breast US is widely used to confirm a diagnosis of cancer, to look for additional disease in the breast, for image-guided breast biopsy and localization, assessment of the axilla, and as a second-look tool in patients with abnormalities found on MRI. MRI of the breast is the most sensitive modality for breast cancer detection. MRI of the breast is used for the assessment of disease extent and detection of additional lesion and seems to be more useful than mammography when staging multifocal and multicentric disease or when DCIS is present. This chapters will provide an overview of when and how to use mammography, DBT, ultrasound, CEM, and MRI for diagnosis and staging of breast cancer.