CAMRT Radiography Practice Exam

What material is used to make the target of the anode in a mammography unit?

1. Tungsten

2. Molybdenum

3. Silver

4. Copper

The correct answer is: Molybdenum

Molybdenum is the preferred material for the target of the anode in a mammography unit due to its effective absorption characteristics and favorable atomic number, which is particularly suitable for the lower-energy X-ray beams typically used in mammography. These lower-energy beams are essential for adequately imaging soft tissues, such as breast tissue, while minimizing the radiation dose to the patient. Molybdenum has a K-shell binding energy of 20 keV, which aligns well with the range of energies produced during mammography. By using molybdenum as the target material, this allows for optimal image quality and contrast, which is crucial for accurately detecting breast abnormalities. Additionally, its properties help in producing X-rays with a narrower energy spectrum, which is beneficial for enhancing the contrast in soft tissue imaging. The other materials listed, while they have applications in different types of radiography, do not possess the same balance of properties that make molybdenum uniquely suited for mammography.