September 2016

Beginning Jan. 1, 2017, the ARRT Radiography exam will refer to radiation measurements in the International System of Units (SI units) only. In the past, we’ve used both conventional and SI units in the Radiography exam.

The change comes as SI units become more common in the U.S. For example, most new equipment now displays radiation dosages in SI units. Textbooks have either converted to SI or are using both standards. And most of the new graduates we surveyed said they’re primarily using SI units in clinical practice.

The change applies only to units of radiation measurements. We’ll continue using both conventional (imperial) and SI (metric) units when referring to temperature, weight, length, area and volume measurements, because all of those measurements are still used clinically.

In addition, the change affects only the Radiography exam. We’ve used only SI units for radiation measurement on our Radiation Therapy exam for some time, and we’ll continue to use both SI and conventional units in the Nuclear Medicine Technology exam.