A mammogram is an X-ray imaging technique used to examine breast tissue. It uses a low-dose X-ray machine to capture detailed images of the breast’s internal structure. These images allow medical professionals to look for changes in the tissue, such as small calcifications or masses, that may indicate early signs of disease. By finding these subtle changes before they can be felt, mammography serves as an important tool for early detection and plays a significant part in managing breast health.
Screening Versus Diagnostic Mammography
The purpose of the exam determines whether it is classified as a screening or a diagnostic mammogram. A screening mammogram is a routine examination performed on individuals who have no noticeable symptoms or breast concerns, often based on age or risk guidelines. This preventive measure aims to detect abnormalities when they are too small to be physically felt by a patient or doctor. Screening exams typically involve two standard X-ray views of each breast and are relatively quick appointments.
A diagnostic mammogram, however, is a targeted examination performed when a patient has a specific symptom, such as a lump, pain, or nipple discharge. It is also used as a follow-up test when a screening mammogram yields an abnormal or unclear result. This type of exam focuses on a specific area of concern and often includes additional, specialized views, such as magnification or spot compression images. The diagnostic procedure is a problem-solving tool that provides the radiologist with more detailed information to determine the cause of the symptom or abnormality.
The Mammography Procedure
Before the procedure, patients must avoid applying deodorants, antiperspirants, lotions, or powders to the chest and underarm area. Certain ingredients in these products can appear as white spots on the X-ray images, potentially mimicking or obscuring calcifications. Patients are asked to undress from the waist up and are given a wrap or gown to wear.
The patient stands in front of the mammography machine, and a technologist places one breast at a time onto a platform. A plastic plate, known as a compression paddle, is then lowered to flatten the breast tissue. Compression is necessary because it spreads out overlapping breast structures, allowing X-rays to penetrate the tissue more effectively. This enables a clearer view of any small masses or irregularities.
The pressure also helps to immobilize the breast, which prevents motion blur and reduces the amount of radiation dose. The compression lasts only a few seconds while the images are captured, and the entire procedure generally takes about 15 to 20 minutes. Modern mammography often uses digital breast tomosynthesis, or 3D mammography, where the machine moves in an arc to take multiple low-dose images. Unlike standard 2D mammography, 3D imaging allows the radiologist to view the breast tissue in thin layers, improving cancer detection and reducing patient callbacks for additional views.
Interpreting the Results
After the images are acquired, a physician specializing in medical imaging, called a radiologist, reviews the mammograms for any suspicious findings. The radiologist looks for specific visual signs, including masses, areas of architectural distortion, and clusters of microcalcifications. The radiologist assigns a result using the Breast Imaging Reporting and Data System (BI-RADS).
The BI-RADS classification uses a range of categories to communicate the findings and recommend the next steps. For instance, a result indicating normal or benign findings suggests a return to routine annual screening. Conversely, an unclear finding requires additional imaging, such as an ultrasound, or a follow-up mammogram to confirm stability. If the classification indicates a higher likelihood of malignancy, the radiologist will recommend a tissue sample, known as a biopsy, to establish a definitive diagnosis.