The radiologist evaluates these mammograms through a computer for long-term archiving. In terms of the patient’s experience, this is somewhat like a traditional film mammogram.
These systems look for unusual areas of density, mass, or calcification in digitized mammographic pictures that could signal the presence of cancer. The CAD system highlights these regions on the pictures, signaling the radiologist to examine them carefully.
This type is also known as three-dimensional (3-D) mammography or digital breast tomosynthesis (DBT). Advanced breast imaging equipment such as this records breast images from various angles and reassembled them (“synthesized”) into a three-dimensional image set.
In this sense, 3-D breast imaging is comparable to computed tomography (CT) imaging, which uses a sequence of thin “slices” to rebuild the body in three dimensions.
How It Works
During a mammogram exam, two firm paddles squeeze a woman’s breasts to spread out the breast tissue.
This compression usually takes place for three reasons:
- It maintains the breast in place, which reduces the risk of x-ray image blurring due to patient movement.
- It helps balance out the contour of the breast, which allows x-rays to travel a shorter distance to the detector. This lowers the radiation dose and enhances the x-ray image quality.
- It permits all tissues to be seen in a single plane to reduce the chance of tiny anomalies being masked by overlying breast tissue.
An x-ray machine produces a series of x-rays that passes through the breast to a detector on the opposite side. A photographic film plate that captures the x-ray image on film, or a solid-state detector that delivers electronic signals to a computer in order to create digital detector images known as mammograms.