CAMRT Radiography Practice Exam

Which of the following is classified as a Traditional Unit?

1. Gray (Gyt)

2. Sievert (Sv)

3. Rem

4. Air Kerma (Gya)

The correct answer is: Rem

The classification of traditional units in radiography is rooted in historical usage prior to the widespread adoption of the SI (International System of Units). The rem is a traditional unit specifically used to measure the biological effect of ionizing radiation. It quantifies the dose absorbed and accounts for the type of radiation and its biological impact on human tissue. The gray, sievert, and air kerma are all part of the SI system. The gray measures absorbed dose, the sievert measures equivalent dose considering biological effects, and air kerma is a measure relating to the radiation exposure in air. These units are more commonly employed in contemporary radiological practices, focusing on standardization and international consistency. In contrast, the rem has historical significance and serves as the traditional method for assessing dose and its potential biological effects. Therefore, it is regarded as a traditional unit in this context.