TMU Blogs

Introduction: Understanding Mammography

Mammography is a specialised imaging technique for examining the breast, primarily to detect various abnormalities, especially breast cancer. While breast imaging can also be performed using ultrasonography or magnetic resonance imaging (MRI), the term “mammography” typically refers to X-ray mammography (XRM), wherein a mammogram is obtained using low-dose X-rays.

Digital Mammography vs. Conventional Mammography

Mammography is performed using dedicated machines specifically designed for breast imaging. These can be classified into:

• Film-screen type (conventional mammography)
• Digital type (Full-Field Digital Mammography or FFDM)

In FFDM, solid-state detectors convert X-rays into electrical signals, producing high-quality digital images on a monitor. This allows for image manipulation, greater diagnostic accuracy, reduced radiation exposure, and shorter procedure times.

Digital Mammography: Types of Mammography Procedures

Mammography is categorised into two primary types based on the purpose of evaluation:

1. Screening Mammography

This type is used for the early detection of breast cancer in asymptomatic women, usually above 40 years of age, and is recommended annually or biennially. However, women at higher risk—due to family history, BRCA gene mutations, or prior chest radiotherapy—may require earlier and more frequent screening.

2. Diagnostic Mammography

Performed when a woman experiences symptoms such as a lump, pain, nipple discharge, or changes in breast shape. Diagnostic mammography often includes additional procedures such as:

• Ductography: Imaging after injecting contrast into the mammary duct.
• Stereotactic Mammography or Hookwire localisation: Placement of a metallic wire to guide surgical removal of non-palpable masses.
• Stereotactic Biopsies: Collection of tissue using a rotating needle for microscopic examination.
• Breast Tomosynthesis: Multi-angle imaging to enhance small lesion detection.
• Contrast-Enhanced Mammography (CEM): Highlights enhancing lesions to improve lesion delineation and detect early malignancy.

Preparation and Best Time for Mammography

The ideal time to undergo mammography is one week after the menstrual period to avoid breast tenderness and eliminate pregnancy risks. Patients should avoid:

• Applying powders, lotions, deodorants, or perfumes.
• Consuming caffeine (especially in sensitive individuals) for at least two weeks prior.

Wiping the breast and axillary area before the procedure helps reduce artefacts.

Procedure Overview and Imaging Techniques

The examination involves compressing the breast using a specialised pad to obtain uniform tissue thickness. Compression aids in:

• Enhancing lesion visibility
• Minimising radiation dose
• Preventing motion artefacts

The Craniocaudal (CC) and Mediolateral Oblique (MLO) views are standard. In some cases, magnified or focused views may be needed. An experienced mammographer typically completes the scan within 30 minutes.

Reporting and BI-RADS Classification

Mammograms are interpreted using the BI-RADS (Breast Imaging Reporting and Database System), which categorises findings into seven standard groups to guide clinical management. A critical diagnostic marker includes microcalcifications, often indicative of Ductal Carcinoma In Situ (DCIS)—an early-stage breast cancer.

Advantages and Limitations

Advantages:

• Detects breast cancer at an asymptomatic and early stage
• Minimally invasive with low radiation risk
• Cost-effective and widely available

Limitations:

• May produce false-negative results in dense breast tissues, common in younger women
• False-positives are more likely in individuals on oestrogen therapy or those with higher risk factors
• Breast implants, particularly subglandular, may obscure tumour visibility

Additional evaluations with CEM, ultrasound, MR mammography, or biopsy are recommended in inconclusive cases.

Conclusion

Digital X-ray mammography remains the most effective and sensitive tool for the early detection of breast carcinoma. Its non-invasive nature, accuracy, and ability to identify microcalcifications make it an indispensable technique in modern breast imaging. Technological advancements like contrast-enhanced mammography and tomosynthesis improve diagnostic confidence and early cancer detection rates.