X-Ray Production and Safety Concepts

There are four requirements necessary for the production of x-rays. They are: an acceleration of electrons, a sudden stopping of electrons, a focusing of electrons and:

• a target with a high melting point

• a source of free electrons

• a target with a high atomic number

• a high electrical potential applied across the tube

Surfaces within a radiographic room that will not be in the direct path of the useful x-ray beam must provide a minimum lead equivalent beam attenuation equal to ___ of lead

• 0.0625

• 0.0025

• 0.02105

• 0.03125

At a distance of 2 meters from the side of a fluoroscopic table, an operators radiation detector device indicates a total of 350 mGya are received for an exam that takes 4 minutes to complete. If the operator were to move to a distance of 3 meters from the table, what would be the new reading on the detection device for this same exam taking 7 minutes to complete?

• 155.5 mGya

• 272.2 mGya

• 378.7 mGya

• 432.0 mGya

The cumulative timer on a fluoroscopic unit is designed to interrupt the production of the fluoroscopic beam after a period of ___ minutes of fluoroscopy has elapsed

• 5 minutes

• 15 minutes

• 10 minutes

• 8 minutes

Which size exposure field below will result in the least gonadal dose to your patient?

• 9.5 x 9.5

• 11 x 14

• 8x 10

• 7x 17

As linear energy transfer (LET) decreases, how is relative biological effectiveness (RBE) affected?

• RBE is not affected by LET

• decreasing LET neutralizes RBE

• decreasing LET increases RBE

• decreasing LET decreases RBE

Which of the following would be considered the least radiosensitive

• fetus

• adult patient

• teenage patient

• pediatric patient

A drop in red blood cell production within the hematopoetic system resulting from radiation therapy treatments delivered to the long bones of the body would be classified as what type of radiation effect?

• local genetic

• general genetic

• local somatic

• general somatic

Given a choice of the following technical factors, select the set that will yield the greatest dose to the patient

• 70 kVp, 300 mA, 0.09 s, 36" SID, 14X 17 IR

• 74 kVp, 500 mA, .15 s, 72" SID, 10x12 IR

• 73 kVp, 300 mA, 0.13 s, 50" SID, 14x17 IR

• 70 kVp, 400 mA, .010 s, 48" SID, 10X12 IR

Given the factors listed below, identify the atom with an atomic number equal to 33

• 15 protons, 17 neutrons

• 33 protons, 33 neutrons,

• 16 protons, 16 neutrons

• 15 protons, 33 neutrons