Protection in CT

Question 1

A miscentering of ________ can produce as much as __________% increase in patient dose.

Answer 1

2 cm; 25

Question 2

For routine head and body computed tomography examinations, effective doses fall into which of the following effective dose ranges?

Answer 2

1 to 10 mSv

Question 3

In CT because of higher effective energy of the x-ray beam, both ____________ and _______________ interactions contribute substantially to the image.

Answer 3

photoelectric; Compton

Question 4

In CT when a series of adjacent slices is obtained, some radiation will also scatter from the slice being made into the adjacent slices. What is this radiation called?

Answer 4

Interslice scatter

Question 5

In the early 2000s various publications calculated individual and population risks of cancer from CT based upon risk estimates from studies of which of the following groups of people?

Answer 5

Atomic bomb survivors

Question 6

The movement or advancement of the patient couch during a CT scan is known as:

Answer 6

table increment.

Question 7

To keep the patient’s radiation dose ALARA, for both initial and follow-up examinations, the image acquisition should:

Answer 7

always be made in the same cardiac phase.

Question 8

With higher radiation exposure to the patient during a computed tomography examination, there is:

Answer 8

an increased associated cancer risk.

Question 9

Which of the following is not typically used during a CT scan?

Answer 9

Direct patient shielding

Question 10

Tube current modulation in CT scanning can:

Answer 10

help to reduce patient dose.