Ch 4: Radiation Protection

The collimator ____________.

• is a solid piece of aluminum

• is always round

• restricts the size and shape of the x-ray beam

• is fitted within the copper stem beneath the molybdenum cup

Which of the following types of position-indicating devices (PIDs) produce excess scatter radiation?

• Round

• Rectangular

• Conical

• Square

Which type of PID would be most effective in reducing patient exposure?

• A 16-inch round PID

• An 8-inch rectangular PID

• A 16-inch rectangular PID

• Conical

The thyroid collar

• is recommended for all intraoral exposures.

• is recommended for all extraoral exposures.

• is placed over the patient’s chest and lap and extends to protect the thyroid.

• is recommended for both intraoral and extraoral exposures.

A rectangular collimator

• restricts the beam 3 times more than a circular collimator.

• restricts the beam less than a circular collimator.

• is considerably larger than a size 2 intraoral receptor.

• decreases patient exposure considerably. 

On some dental x-ray machines, only the ____________ can be altered; the other parameters are preset by the manufacturer.

• exposure time 

• kilovoltage

• PID length

• Milliamperage

Which of the following can you do after x-ray receptor exposure to reduce(s) the amount of x-radiation your patient receives?

• Selecting proper exposure settings

• Proper instrument technique

• Proper placement of the lead apron

• Proper image retrieval

The primary principle of operator protection guidelines is that the operator must

• hold the tubehead during x-ray exposure.

• remain in the room with the patient while the receptor is being exposed.

• avoid the primary beam. 

• hold the receptor in the patient’s mouth with their own finger.

In order to avoid the primary beam while taking dental images, you should stand at a ____-degree to ____-degree angle to the beam.

• 0; 45

• 45; 90

• 90; 135

• 135; 180

Radiation monitoring can be used to protect the dental radiographer and includes monitoring of

• equipment but not personnel.

• personnel but not equipment.

• both equipment and personnel.

• drywall for residual radiation