Nuclear medicine practice question: Half-Value Layer

You are conducting a radiographic imaging experiment using four different materials with distinct Half-Value Layers (HVLs). The materials and their respective HVLs are as follows:
Material A: HVL = 5 mm of aluminum
Material B: HVL = 3 mm of lead
Material C: HVL = 8 mm of copper
Material D: HVL = 6 mm of steel
You have sheets of these materials, each with a thickness of 10 mm. Your task is to determine which material, at a thickness of 10 mm, attenuates the most photons.
Which material is expected to exhibit the highest photon attenuation under these conditions?

A) Material A
B) Material B
C) Material C
D) Material D

B) Material B

Explanation:

In radiography, the Half-Value Layer (HVL) is a measure of the thickness of a material required to reduce the intensity of a beam of radiation by half. The larger the HVL, the better the material is at attenuating the radiation.

In this case, Material B (lead) has the smallest HVL (3 mm), indicating that it requires the least thickness to attenuate the radiation by half. Therefore, at a thickness of 10 mm, Material B (lead) would attenuate the most photons compared to the other materials listed.