mammography

mammography
Name	Mammography
Caption	A modern mammography unit.
Purpose	Detection of breast cancer
Test of	Breast
Based on	X-ray
MeshID	D008327

mammography is a specialized medical imaging technique that uses low-dose X-ray to examine the human breast. It serves as the primary tool for the early detection of breast cancer and other breast pathologies. The procedure is performed using a dedicated machine that compresses the breast to obtain high-resolution images for analysis by a radiologist. Widespread screening programs, such as those recommended by the American Cancer Society and the U.S. Preventive Services Task Force, have significantly contributed to reducing mortality from breast cancer.

Overview

The fundamental technology behind this imaging modality involves the use of ionizing radiation to create detailed pictures of internal breast structures. Developed from early radiography techniques, modern digital systems, including digital mammography and tomosynthesis, have largely replaced older film-based methods. Key organizations like the Food and Drug Administration regulate the equipment and standards, while bodies like the American College of Radiology oversee accreditation and quality assurance programs. The efficacy of population-based screening was demonstrated in large trials like the Health Insurance Plan of Greater New York study and the Swedish Two-County Trial.

Procedure

During the examination, a technologist positions the patient's breast on a specialized imaging plate. A compression paddle, often made of polycarbonate, is then lowered to flatten the breast tissue, which improves image quality and reduces radiation scatter. Standard views include the craniocaudal view and the mediolateral oblique view to visualize as much tissue as possible. The process is typically overseen by professionals certified by the American Registry of Radiologic Technologists, and the resulting images are interpreted by physicians board-certified by the American Board of Radiology.

Types of mammography

The two primary technological categories are screen-film and digital systems. Digital mammography, or full-field digital mammography, converts X-rays into electronic signals viewed on computer monitors, offering advantages in image manipulation and storage. A more advanced form, digital breast tomosynthesis, creates a three-dimensional dataset by capturing images from multiple angles, helping to reduce the masking effect of overlapping tissue. Other specialized techniques include contrast-enhanced mammography, which uses an iodinated contrast agent to highlight tumor angiogenesis, and galactography, used to evaluate the lactiferous ducts in cases of nipple discharge.

Indications and screening guidelines

The primary application is for population-based screening of asymptomatic women. Major guidelines, such as those from the American Cancer Society and the U.S. Preventive Services Task Force, recommend regular screening beginning at specific ages, though the exact age and frequency vary. It is also used diagnostically to evaluate clinical findings like a palpable lump discovered during a physical exam or an abnormality seen on other imaging like breast ultrasound. Specific high-risk populations, such as carriers of BRCA1 or BRCA2 gene mutations, may be advised to begin screening earlier under protocols from institutions like the National Comprehensive Cancer Network.

Interpretation and results

Radiologists analyze the images using a standardized reporting system called the Breast Imaging Reporting and Data System, developed by the American College of Radiology. This system categorizes findings from 0 (incomplete) to 6 (known biopsy-proven malignancy), guiding next steps. Common benign findings include fibroadenomas and clusters of microcalcifications, while suspicious signs include spiculated masses and architectural distortion. When a finding requires further evaluation, additional imaging with spot compression or magnification views may be performed, or a tissue sample may be obtained via procedures like stereotactic biopsy.

Risks and limitations

The procedure involves exposure to low levels of ionizing radiation, though the benefit of early cancer detection is generally considered to outweigh this small risk. A significant limitation is the occurrence of false-positive results, which can lead to patient anxiety and unnecessary follow-up procedures like biopsy. Conversely, false-negative results can occur, particularly in women with dense breast tissue, where cancers may be obscured. Other drawbacks include the discomfort of compression and the potential for overdiagnosis, where indolent cancers are detected and treated unnecessarily, a topic of ongoing debate in journals like *The New England Journal of Medicine*.

Category:Medical imaging Category:Breast cancer Category:Radiology