Chapter 5 Quiz

Question 1

Radiation used to create diagnostic x-rays is produced by a process called _______.

electron capture
bremsstrahlung
internal conversion
pair produciton

Answer 1

bremsstrahlung

Question 2

The beam filter next to the x-ray tube is a prefilter and is called a _______.

low-pass filter
high-pass filter
buttersworth filter
bow-tie filter

Answer 2

bow-tie filter

Question 3

Thin collimation on a CT examination creates _________.

-poorer spatial resolution
-more volume averaging
-increases in streak artifacts
-increases in quantum noise

Answer 3

increases in quantum noise

Question 4

If an MSCT is used the table movement is 10mm per rotation and the total slice volume is 10mm, then the volume pitch would be _________.

1
2
10
0.75

Answer 4

1

Question 5

What is the CT number for water?

0
100
1000
-100

Answer 5

0

Question 6

The formula to calculate the CT number is ______.

-CT tissue=tissue/waterx1000
-CT tissue=tissue-waterx1000
-CT tissue=(tissue-water)/waterx1000
-CT tissue=(tissue-water)xwaterx1000

Answer 6

CT tissue=(tissue-water)/waterx1000

Question 7

Which of the following CT artifacts would be attributed to faulty radiation detectors?

-streak artifacts from dense bone
-blurred diaphragm in the coronal plane images
-spoke pattern radiating from metallic objects
-dim concentric rings on axial slices

Answer 7

dim concentric rings on axial slices

Question 8

Before the patient CT scan starts, aquiring an estimate of radiation exposure is reported by which value?

kVp
CTDI
mA
mAs

Answer 8

mA

Question 9

What is the CT number for air?

1000
0
-100
-1000

Answer 9

-1000

Question 10

Pediatric CT studies should use lower parameters for _______.

kVp
mA
rotation speed
both kVp and mA

Answer 10

both kVp and mA