A bilateral mammogram with tomosynthesis, also known as 3D mammography or digital breast tomosynthesis (DBT), combines traditional mammography with 3D technology. This breast imaging technique offers a detailed view of breast tissue for both screening and diagnosis.
Understanding Traditional Mammography
Traditional mammography uses X-rays to produce two-dimensional (2D) images of the breast. During the procedure, the breast is compressed between two plates, and images are captured from two angles: typically top-to-bottom and an angled side-to-side view. This method has been foundational in breast cancer screening.
Despite its effectiveness, conventional 2D mammography has limitations. Challenges include the superimposition of breast tissue, where overlapping structures can obscure potential abnormalities. This tissue overlap can also lead to normal breast tissue appearing suspicious, sometimes resulting in unnecessary follow-up imaging. Additionally, dense breast tissue, which appears white on a mammogram, can mask cancers that also appear white, making detection more challenging.
The Role of Tomosynthesis
Digital Breast Tomosynthesis (DBT) introduces 3D imaging to breast examinations. This technology takes multiple low-dose X-ray images as the X-ray tube moves in a slight arc over the compressed breast, capturing numerous projection images from various angles.
A computer processes these images, reconstructing them into thin, layered views or “slices” of the breast tissue. This allows radiologists to scroll through the breast, layer by layer, similar to flipping through a book. Tomosynthesis aims to overcome the tissue overlap that limits 2D mammography, offering clearer visualization of breast structures.
The Combined Imaging Process
A bilateral mammogram with tomosynthesis images both breasts as a single procedure. The experience is similar to a traditional 2D mammogram. A trained technologist positions each breast on a platform, and a clear plastic plate gently compresses the breast. This compression evens out breast thickness and ensures clear imaging.
While the breast remains compressed, the X-ray arm sweeps in an arc, capturing multiple images for 3D reconstruction. The entire process, including both 2D and 3D imaging for both breasts, typically takes 10 to 15 minutes for a screening examination, with each compression lasting only a few seconds.
Advantages of 3D Mammography
Tomosynthesis enhances breast cancer detection compared to traditional 2D mammography. Studies indicate that 3D mammography can increase the detection rate of invasive breast cancers by 25% to 41%, helping identify smaller or more subtle abnormalities hidden by overlapping tissue in a 2D image.
It also reduces the need for follow-up imaging, often called “callbacks.” 3D mammography can decrease callback rates by about 15%, reducing patient anxiety and the burden of additional tests. This technology benefits individuals with dense breast tissue, as layered views help radiologists differentiate between dense tissue and potential cancers. Viewing breast tissue in thin slices also supports more accurate localization of detected abnormalities.
Preparing for Your Exam
Proper preparation helps ensure clear and accurate images.
Avoid applying deodorants, antiperspirants, powders, lotions, creams, or perfumes to your underarms or breasts on the day of your exam. These products can contain metallic particles that may appear as white spots on X-ray images, potentially interfering with results.
Wear comfortable, two-piece clothing, as you will need to undress from the waist up.
Inform the technologist about any breast symptoms, implants, or prior breast surgeries.
Bring previous mammogram images or arrange for them to be sent to the facility for comparison.
Schedule the exam when your breasts are least sensitive, typically one to two weeks after your menstrual period, to enhance comfort.