Ch. 13 Minimizing Patient Dose (Exp II)

Question 1

The conscientious radiographer can reduce the patient dose by at least ____ in most examinations by choosing appropriate exposure factors.

Answer 1

50%

Question 2

The maximum exposure received by the patient is at:

Answer 2

The skin entrance to the body

Question 3

Which of the following radiographic procedure delivers the lowest entrance skin exposure?

a. Hip
b. Pelvis
c. Lumbar spine
d. Elbow

Answer 3

d. Elbow

Question 4

The Food and Drug Administration (FDA) sets an entrance skin exposure limit of ____ R.min for fluoroscopic systems in the US.

Answer 4

11.5 R/min

Question 5

The radiation intensity from a diagnostic x-ray unit will vary in:
______ relationship with mAs
______ relationship with the square of the kVp
______ relationship with the square of the distance

Answer 5

• Direct relationship with mAs
• Direct relationship with the square of the kVp
• Inverse relationship with the square of the distance

Question 6

To reduce patient exposure, the _____ consistent with image quality should be selected.

Answer 6

Highest kVp

Question 7

Which x-ray generator will substantially decrease the patient entrance skin exposure?

Answer 7

Three-phase, 12 pulse

Question 8

Patient entrance skin exposure decreases as:

Answer 8

SID increases

Question 9

When the primary-beam field size ___, the patient exposure ____.

Answer 9

Decreases; decreases

Question 10

Each of the following is a type of gonad shield EXCEPT:

a. Flat contact
b. Shadow
c. Collimator
d. Shaped contact

Answer 10

c. Collimator

Question 11

The use of a grid will:

Answer 11

Increase patient exposure

Question 12

An effective method of reducing patient exposure is to use:

Answer 12

The highest speed possible image receptor

Question 13

Entrance skin exposure is _____ exposure.

Answer 13

Maximum

Question 14

Skull radiography routinely includes a posterior-anterior (PA) projection. This is intended to:

Answer 14

Reduce dose to the lens of the eye

Question 15

The approximate entrance skin exposure (ESE) for a radiographic study taken at 90 kVp and 23 mAs is:

Answer 15

103.5 mR

Question 16

When SID or SOD increases:

Answer 16

Patient ESE decreases

Question 17

When comparing ESE and actual dose to an area of interest:

Answer 17

Actual dose is lower than ESE

Question 18

In an effort to reduce dose, the recommended SID for routine radiography is:

Answer 18

44-48 inches

Question 19

In an effort to minimize patient dose:

a. The small focal spot should be used
b. The large focal spot should be used
c. Beam filtration should be minimum
d. None of the above

Answer 19

d. None of the above

Question 20

Of the choices below, the combination of exposure factors that would minimize patient dose would be:

a. 24 mAs, 80 kVp, 8x10” field size, 44” SID
b. 12 mAs, 92 kVp, 8x10” field size, 40” SID
c. 6 mAs, 106 kVp, 8x10” field size, 44” SID
d. 24 mAs, 80 kVp, 10x12” field size, 40” SID

Answer 20

c. 6 mAs, 80 kVp, 8x10” field size, 44” SID