Radiologic Technologist Practice Exam

Which of the following BEST describes the term air kerma?

1. Weighted for tissue type

2. Absorbed dose

3. Kinetic energy transferred

4. Equivalent dose

The correct answer is: Kinetic energy transferred

The term "air kerma" is best described as the kinetic energy transferred to charged particles, specifically electrons, by photons in air. It quantifies the amount of energy imparted by ionizing radiation to a specific volume of air, providing important information about radiation exposure in diagnostic imaging and radiation therapy. Air kerma specifically refers to the energy transferred from radiation to matter (in this case, air) and is measured in units of joules per kilogram (J/kg), also referred to as gray (Gy) in practical application. This concept is critical in radiologic science as it helps in assessing radiation dose and understanding how much energy is available to cause ionization in tissues. The other options, while related to the field of radiologic technology, do not capture the specific definition of air kerma. Weighted for tissue type pertains to dose considerations affecting tissues (quality factor), absorbed dose refers to the total energy absorbed by a material (not confined to air), and equivalent dose factors in biological effects and radiation type, none of which specifically describes the kinetic energy transferred to charged particles in air.