Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CT/MRI QUIZ > CT Image Quality and Display > Flashcards

CT Image Quality and Display Flashcards

1
Q

Primarily controlled by resolution and noise consideration

A

CT IMAGE QUALITY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Varied with window level and
window width controls

A

DENSITY AND CONTRAST

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

CT image: requires __ contrast
difference

A

4%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Diagnostic image: requires __
contrast difference

A

10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Depends on pixel, voxel and matrix size

A

RESOLUTION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

resolves high-contrast
objects 1.5 times its size

A

Pixel size:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

+Voxel size: __mm

A

8-13mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

seen better in smaller pixel size

A

+High contrast objects:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

seen better in a larger pixel size

A

Low contrast objects:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

+CT: __mm resolving power
+Conventional: __mm resolving power

A

CT: 0.35mm
Conventional: 0.25mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

+Undershoot and overshoot
+Occurs when two objects have >60% difference in attenuation
coefficients

A

INTERFACE ARTIFACT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Occurs in objects of greatly different contrast

A

INTERFACE ARTIFACT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

+ Star pattern artifact is an example of?

A

INTERFACE ARTIFACT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Compensation: large matrix size & reconstruction algorithm

A

INTERFACE ARTIFACT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Achieved by choosing a smaller
display FOV

A

CT MAGNIFICATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Produces an image with less tissue
per voxel

A

CT MAGNIFICATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

+Provides a larger image of a smaller
area of interest

A

CT MAGNIFICATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

+Provides higher resolution

A

CT MAGNIFICATION

19
Q

Magnified CT matrix appears?

A

Pixelated & Less sharp

20
Q

Can be found in all digital system
+Directly related to the amount of
data collected by the detector
+Comprises 3-5% of the image

A

Noise

21
Q

Affects the low contrast resolving
ability of the CT unit
+Noise evaluation: water phantom
+Average Reading: at least 100 pixels
(10x10 matrix)

A

Noise

22
Q

+Can be found in all digital system
+Directly related to the amount of
data collected by the detector
+Comprises 3-5% of the image

A

Noise

23
Q

+A function of exposure time
+Controlled by the quantity of data
detected

A

Motion

24
Q

The last phase in the creation of
the CT image

A

CT IMAGE DISPLAY

25
Q

Includes all of the system
components necessary to convert
digital data created from the
reconstruction process to electrical
signals needed by the CT display
monitor (DAC)

A

CT IMAGE DISPLAY

26
Q

Controls the digital image
production process
+Series of mathematical formulas
(algorithms)

A

PROCESSING AND DISPLAY PROGRAMS

27
Q

Display parameters?

A

+Display parameters
+ Window width
+ Window level
+ Reconstructions
+ Enhancements

28
Q

Used to display CT images
+– >2000 different HU (hounsfield units) values

A

GRAY SCALE

29
Q

+High HU: assigns __ shades of gray
+Lower HU: assigns __ shades of gray

A

(High - Lighter and Low - Darker)

30
Q

+____: displays only __ shades of gray

A

Monitor & 256

31
Q

Human Eye:
+Limited to <__ shades of gray
+Cannot appreciate contrast differences <__

A

40% & 10%

32
Q

Can differentiate contrast <1%

A

CT

33
Q

Mechanism that determines the quantity of HU represented as shades
of gray on a specific image

A

+Window Width

34
Q

+ 500-2000 HU
+ Decrease image contrast
+ Best for imaging tissues (CT numbers vary greatly)
+ e.g. Lung imaging

A

WIDE WINDOW WIDTH (WIDE WW)

35
Q

+50-500 HU
+Increase image contrast
+Best in imaging the brain (CT numbers not vary greatly)

A

+Narrow WW

36
Q

+ Mechanism that selects the center CT value of the window width

A

+Window Center/Level:

37
Q

+___ WL: makes the image darker
+___ WL: makes the image brighter

A

WINDOW LEVEL
INCREASE
DECREASE

38
Q

+Localizer scan, Scout, Surview,
Topogram, Preview or Pilot
+A localization image (2D)
+The first image of an examination
+Slightly poorer image quality

A

SCANOGRAM

39
Q

Used by RT to confirm exact
centering of the patient
+Used by radiologist to
describe the structural
locations

A

GRID APPLICATION

40
Q

+Used to outline the area of interest
+Used to determine the HU
+Used to display the area’s
measurement within the patient
+Used for volume estimates

A

CURSOR

41
Q

Reverse the image from left to
right & vise versa
+Reverse the density display
from black to white & vice versa

A

REVERSE DISPLAY

42
Q

+Uses only the image data
+Does not improve resolution
+Not the same as decreasing the
FOV
+Allows the image detail to be clearly
seen

A

IMAGE MAGNIFICATION

43
Q

+Added text on the images for
descriptions or anatomical labeling
+Arrows
+Markers
+Used to display optional information
+Allows operator to annotate images
with
+Words
+Phrases

A

IMAGE ANNOTATION

CT/MRI QUIZ (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions