American Society of Radiologic Technologist (ASRT) Practice Exam

Which factor is critical for minimizing motion blur in radiographic imaging?

1. Long exposure time

2. Short exposure time

3. Using a large focal spot

4. Increasing patient mobility

The correct answer is: Short exposure time

Short exposure time is critical for minimizing motion blur in radiographic imaging because it reduces the duration during which the image receptor is exposed to the x-ray beam. When the exposure time is prolonged, even slight movements from the patient or the imaging equipment can result in a blurred image. A shorter exposure diminishes the likelihood that any motion will affect the captured image since it captures the x-ray data over a shorter period, effectively "freezing" the moment. Using a focal spot size can affect image sharpness, but the size of the focal spot itself does not directly address the issue of motion blur, and therefore does not contribute as significantly as exposure time. Long exposure times would increase the potential for motion blur, and increasing patient mobility would only exacerbate the problem if the patient were to move during a longer exposure. Thus, employing a short exposure time is the most effective method for ensuring clarity in the images produced.