American Registry of Radiologic Technologists (ARRT) Practice Exam

The correct answer is that LET measures the quality of radiation. Linear Energy Transfer (LET) is a concept used in the field of radiation physics to describe how much energy a radiation particle transfers to the material it passes through per unit distance. This is important because different types of radiation (such as alpha particles, beta particles, or gamma rays) interact with matter in varying ways, impacting their biological effects.

High LET radiation, such as alpha particles, transfers a significant amount of energy over a short distance, leading to potentially more severe biological damage in tissues. In contrast, low LET radiation, such as gamma rays, tends to transfer energy more spread out over a longer distance, resulting in different biological implications.

While the other options consider various aspects related to radiation, they do not specifically address the concept of LET. The quantity of radiation pertains to how much radiation is present, intensity of exposure relates to the strength of the radiation field, and energy absorption focuses on how much energy is deposited in the tissue. In essence, LET is a measure of the quality of radiation based on its energy deposition characteristics, highlighting its importance in understanding radiation's effects on matter and biological systems.