Mammography is a specialized imaging technique critical for early detection and diagnosis of breast diseases, particularly breast cancer. As biomedical engineers in Kenya, maintaining mammography equipment ensures reliable image quality and patient safety, supporting hospitals and clinics in delivering effective breast health services. Understanding mammography's principles and the breast's anatomy is essential for targeted maintenance that preserves diagnostic accuracy and extends equipment lifespan.

3.1 Meaning and overview of mammography

Mammography is a radiographic imaging process designed specifically to visualize the internal structure of the breast. It uses low-dose X-rays to create detailed images that help detect abnormalities such as tumors, cysts, and calcifications. Given the rising incidence of breast cancer in Kenya, mammography plays a pivotal role in early diagnosis, improving treatment outcomes and survival rates. Biomedical engineers must comprehend mammography's operating principles to ensure equipment functions optimally within healthcare facilities ranging from county hospitals to private clinics.

3.1.1 Definition of mammography

Mammography is a diagnostic procedure that employs low-energy X-rays to produce high-resolution images of breast tissue. Unlike general radiography, mammography focuses on capturing fine details of soft tissue structures within the breast, which is challenging due to the tissue's low natural contrast. The technique involves compressing the breast to spread tissue evenly, reducing radiation dose while enhancing image clarity. Kenyan healthcare providers use mammography as a screening tool for asymptomatic women and as a diagnostic aid when abnormalities are suspected.

3.1.2 Purpose and clinical significance of mammography

The primary purpose of mammography is to detect breast abnormalities at an early stage before they are palpable or symptomatic. Early detection through mammography significantly increases the chances of successful treatment and reduces mortality rates. In Kenya, national screening programs rely on mammography to identify breast cancer in women over 40, aligning with global best practices. Additionally, mammography assists in monitoring known breast conditions, guiding biopsies, and evaluating treatment responses.

Purpose of mammography

• Early detection of breast cancer, enabling timely intervention and improved prognosis.
• Identification of benign breast conditions like cysts and fibroadenomas to avoid unnecessary procedures.
• Evaluation of breast symptoms such as lumps, pain, or nipple discharge.
• Guidance for needle biopsies and surgical planning through precise localization of lesions.
• Monitoring the effectiveness of ongoing breast cancer treatments to adjust therapy accordingly.

Clinical significance in Kenyan context

• Addresses the increasing breast cancer burden by facilitating nationwide screening initiatives.
• Enhances diagnostic accuracy in county and referral hospitals equipped with mammography units.
• Supports public health education on breast health awareness and self-examination practices.
• Provides data for epidemiological studies on breast disease patterns across different Kenyan regions.
• Reduces healthcare costs by detecting disease early, minimizing advanced-stage treatment expenses.

3.1.3 Principles of mammography imaging

Mammography relies on the differential absorption of X-rays by various breast tissues to create contrast on the image. Dense glandular and connective tissues absorb more X-rays and appear white, whereas fatty tissue allows more X-rays to pass through, appearing darker. The equipment uses a specialized X-ray tube with a molybdenum or rhodium target to produce low-energy photons optimal for soft tissue imaging. Breast compression is applied to minimize motion blur and reduce tissue thickness, improving image resolution and reducing radiation dose.

3.1.4 Types of mammography techniques

Various mammography techniques have evolved to enhance image quality and diagnostic capabilities. Standard full-field digital mammography (FFDM) is widely used in Kenyan hospitals for routine screening and diagnosis. Digital breast tomosynthesis (DBT), or 3D mammography, provides sectional images reducing tissue overlap, improving lesion detection. Contrast-enhanced mammography (CEM) uses contrast agents to highlight vascularity associated with tumors. Each technique requires specific maintenance protocols to preserve equipment performance and patient safety.

Common mammography techniques

• Full-field digital mammography (FFDM): Produces digital images for easy storage and manipulation; common in Kenyan referral hospitals.
• Digital breast tomosynthesis (DBT): Acquires multiple images from different angles to create 3D reconstructions, improving detection in dense breasts.
• Screen-film mammography: Traditional technique using film; largely replaced by digital methods but still found in some rural clinics.
• Contrast-enhanced mammography (CEM): Uses iodine-based contrast agents to enhance visualization of malignant lesions.
• Portable mammography units: Mobile systems used in outreach programs to increase accessibility in remote Kenyan communities.

Chapter Summary

This chapter explored the meaning and overview of mammography, highlighting its importance in breast cancer detection. The structure of the breast was examined, focusing on glandular tissue, ducts, and lymph nodes, and their significance in producing clear and accurate images. The fundamental principles of mammography were discussed, emphasizing the technical aspects that ensure high-quality imaging. Special techniques and modalities such as tomosynthesis were introduced, alongside approaches for fault diagnosis and essential maintenance procedures to keep equipment functioning optimally. Safety procedures were underscored to protect both patients and operators during mammographic examinations. Common artifacts that may appear in mammographic images were identified, explaining their causes and how to minimize them. Finally, the chapter covered the application of different scan types to suit various diagnostic needs in clinical practice.