Radiation protection

A technique of 80 kVp at 20 mAs is changed by the 15 percent rule so that kVp rises and receptor exposure stays about the same. What is the new technique?

An AEC exposure is made with the active detector under a metal hip prosthesis. What is the most likely result?

Before an AP abdomen on an anxious adult, which step most directly helps prevent a repeat caused by motion?

Why does a dose area product (DAP) meter read nearly the same whether it is near the collimator or farther along the beam?

A digital chest image looks excellent, but the exposure indicator shows the receptor received about twice its target exposure. What does this mean for the patient?

Why should the x-ray field never be opened larger than the image receptor?

A tube operated above 70 kVp has 0.5 mm Al equivalent inherent filtration, and its collimator assembly adds 1.0 mm Al equivalent. What is the least additional aluminum filter needed to reach the NCRP minimum total filtration?

For fluoroscopy on a small infant, which change is a recognized way to lower patient dose?

A technique of 30 mAs is used with an 8:1 grid. The radiographer changes to a 16:1 grid. Using conversion factors of 4 for 8:1 and 6 for 16:1, what new mAs is needed?

Image Wisely promotes radiation safety in imaging of which group?

For fluoroscopy of an adult abdomen, which combination of exposure factors generally gives the lower patient dose rate for an acceptable image?

What does positive beam limitation do on a radiographic unit?

How does pulsed fluoroscopy lower patient dose compared with continuous fluoroscopy?

A lateral knee must be repeated because the patient moved. What does the repeat do to the patient's dose for that projection?

For general use of a mobile C-arm fluoroscope, what minimum source-to-skin distance do federal rules require?

For a vertical C-arm projection, why is the x-ray tube placed under the table rather than above the patient?

Why must the useful beam never be directed at the control booth wall?

Why should a fluoroscopist avoid placing a lead-gloved hand in the primary beam?

A radiographer standing 2 m from a fluoroscopy patient receives 0.2 mGy per hour. What rate will she receive if she moves to 1 m?

Why is lead used for aprons and barriers?

Federal rules limit leakage radiation through the tube housing to what level, measured at 1 m from the source?

During a mobile chest exposure, a radiographer wears an apron and stands at least 2 m away. Where should she stand to receive the least scatter?

A radiographer finds a container with the radiation symbol left in a hallway. What should she do?

Why does a remote-controlled fluoroscopy room lower staff dose compared with a conventional room?

How is a thermoluminescent dosimeter (TLD) read?