Cone Beam Basics Flashcards
1
Q
Digital image processing/modifications include:
A
- compression
- imagining manipulations
- image reconstruction
2
Q
Imaging manipulations=automated image analysis which includes:
A
Qualitative image analysis & Quantitative image analysis
3
Q
Imaging manipulation that changes pixel’s digital value:
A
Qualitative
4
Q
Imaging manipulation that counts the number of pixels:
A
Quantitative
5
Q
Data is utilized by other software programs and produces different image presentations:
A
Image reconstruction
6
Q
Label the following views from the spiral CT scan 3D image reconstruction:
A
- caudal cranial view
- buccal view
- distal view
- lingual view
- mesial view
- occlusal view
7
Q
You don’t do a CBCT ____, you do a CBCT ____
A
image; scan
8
Q
Use of computers to generate multiple images of an object from digitized density information obtained from various signals; X-radiation (MDCT, CBCT), magnetic fields (MRI), sonar radiation (ultrasound), etc.
A
Computed tomography
9
Q
Two forms of X-ray CT:
A
- CBCT (cone beam computed tomography)
- MDCT (multidetector computed tomography)
10
Q
CBCT & MDCT are both forms of:
A
X-ray CT
11
Q
CBCT was developed in Japan & Europe before:
A
2000 A.D.
12
Q
What was the first commercially available Cone Beam system in the United States?
A
NewTom (2001)
13
Q
What version of NewTom was created in 2001?
A
NewTom 9000
14
Q
NewTom 9000 was later renamed:
A
NewTom 3G
15
Q
The NewTom 9000/NewTom 3G is similar panoramic but captures:
A
Density values of the whole object at different angles
16
Q
NewTom 9000 (2001) is similar to the first:
A
MDCT (1971)
17
Q
Describe the change of design from the NewTom 3G to the NewTom VGi:
A
Laydown version —-> stand up version
18
Q
Label the names of the following machines:
A
Left: NewTom 3G
Right: NewTom VGi
19
Q
How is the NewTom VGi similar to a pano?
A
The patient stands while getting scanned
20
Q
For NewTom VGi, the imaging capture process is ______ while the image processing takes _____
A
short; longer
21
Q
What device produced by Sirona is smaller and used more often?
A
Orthophos XG 3D
22
Q
Sironas bigger model= ____
Sironas smaller model= _____
A
Galileo
Orthophos
23
Q
what models did I-cat FLX create?
A
V8
V10
V17
24
Q
What is significant about I-cat FLX V8, V10 & V17 models?
A
Sit down models
25
Describe the advantages & disadvantages of a sit down unit:
Takes more time to get patient settled in but less chance for motion artifact
26
The faster the scan, the _______ but the lower the _______
less information; dose of radiation
27
T/F: Most of the sit down units have a larger detector so they tend to be more expensive
T
28
List what CBCT models are made by CareStream:
CS 8100
CS 9300 select
29
CareStream was originally ____ but went ____
Kodak; Bankrupt
30
What models are shown in the following images?
CS 8100 (Left)
CS 9300 select (Right)
31
What models are shown in the following images?
I-cat FLX (V8, V10 or V17 model)
32
What model are shown in the following images?
Sirona Galileo (bigger model)
33
What models are shown in the following images?
Sirona Orthophos (smaller model)
34
Both the CS 8100 & CS 9300 select are ______ CBCT units
Stand up
35
Va Tech "Picasso" models are what type of CBCTs?
This company has both sit down & stand up units
36
What model is seen in the image below?
VaTech "Green21" model
37
What models are shown in the following images?
Va Tech Picasso models
38
What model is seen in the image below?
Morita X800
39
What CBCT unit is UMKC getting next year?
Morita X800
40
The larger the scan, the more time it takes = _____ dose
the higher the dose
41
Due to a larger scan taking more time and ultimately having a higher radiation dose, you would prefer the patient to:
sit in a chair so they don't have to retake the scan
42
What type of CBCT scanner do we currently have in the school that is Dr. Briners baby?
I-CAT FLX
43
What type of CBCT is seen in the image below?
Morita 3D accuitomo 170
44
The CBCT brand Planmeca has what models:
Planmeca Viso G5
Panacea Viso G7
45
Describe the difference between the FOVs of Planmeca Viso G5 vs. Planmeca Viso G7:
Planmeca Viso G5: FOVS: 3X3cm 30x17cm
Planmeca Viso G7: FOVS: 3x3cm 30x19cm 30x30
46
Aside from the FOVs another difference seen between Planmeca Viso G5 vs. Planmeca Viso G7 is that the G7 uses a:
2-scan technique
47
T/F: Nearly all CBCT units are good quality, high-end imaging equipment made for a very competitive market place
True
48
CBCT units become outdated due to competition from:
1. Competitor brands
2. Technical innovations
49
List examples of technical innovations that contribute to CBCT units becoming outdated:
1. memory
2. bit depth
3. FOV options
4. operating systems
5. compatibility with software technologies
50
What technical innovation is being described below?
-How well it works with other digital systems to store the images
Memory
51
What technical innovation is being described below?
Resolution
Bit depth
52
What technical innovation is being described below?
Site of scanner
FOV options
53
The lifetime of a CBCT unit is around:
6-8 years
54
Panoramic if used properly can last up to:
20 years (CBCTs are different)
55
What factors contribute to the shorter lifespan (6-8 years) of a CBCT unit?
1. X-ray tube burns out
2. Software system gets old (older systems don't integrate well with newer softwares)
3. Operating system changes
56
List the benefit of cone beam imaging:
Less radiation than other forms of CT (i.e. MDCT) for hard tissue imaging
57
Explain the concept of less radiation from cone beam imaging for hard tissue imaging compared to other forms of CT:
1. less scanning of X-radiation
2. lower radiation
58
List the effective dose for the following CT exams:
1) CBCT large FOV:
2) CBCT medium FOV:
3) CBCT small FOV:
4) MDCT-head:
5) MDCT- abdomen:
6) MDCT- chest:
all measured in microSV (uSv)
1) CBCT large FOV: 68-1073
2) CBCT medium FOV: 45-860
3) CBCT small FOV: 19-652
4) MDCT-head: 960-1500
5) MDCT- abdomen: 5300
6) MDCT- chest: 5800
59
List the effective dose for the following CT exams in days background radiation:
1) CBCT large FOV:
2) CBCT medium FOV:
3) CBCT small FOV:
4) MDCT-head:
5) MDCT- abdomen:
6) MDCT- chest:
1) CBCT large FOV: 8-126
2) CBCT medium FOV: 5-101
3) CBCT small FOV: 2-77
4) MDCT-head: 101-177
5) MDCT- abdomen: 624
6) MDCT- chest: 682
60
1 day of background radiation equals around:
8.5 microSv (uSv)
61
MCDT stands for ______ NOT _____
Multi-detector CT; Medical CT
62
Why is there so much overlap in the effective dose for common CT exams?
There are other factors that affect the doe, not just considering the question of the size of the area being scanned
63
CBCT Dosimetry study values vary because:
Studies are NOT directly comparable
64
CBCT Dosimetry study values vary because studies are NOT directly comparable, list examples of what we mean by this:
1. variations in experimental methodologies
2. different devices & settings
3. different size FOVs (including shapes of FOVs)
4. differences in high & low resolution scans
5. dosimetry phantoms
6. ICRP E(1990) vs. E(2007)
Don't need to memorize
65
1. variations in experimental methodologies
2. different devices & settings
3. different size FOVs (including shapes of FOVs)
4. differences in high & low resolution scans
5. dosimetry phantoms
6. ICRP E(1990) vs. E(2007)
These are all causes of:
Effective dose of CT scans overlap
66
Factors affecting dose of CBCT scans:
1. FOV
2. Exposure
3. Voxel
4. Sensors
67
FOV=
Field of view
68
The field of view, referred to as the FOV refers to the:
size of the volume captured in the scan
69
Almost all CBCT systems on the market capture a volume (FOV) that shaped like a:
Cylinder (tin can)
70
The FOV is expressed in two numbers, typically measured in:
Cm (online)
MM (slides)
71
The FOV is expressed in two numbers. The first number typically refers to the _____ of the cylinder, while the second number refers to the _____
diameter of the circular face of the cylinder (top of the pop can)
height
72
What is the shape of a flat panel detector (CBCT FOV)?
Cylinder (pop can)
73
List the steps of the CBCT unit:
1. image acquisition
2. Raw data (2D projections)
3. Image reconstruction (3D dataset)
4. Visualization (2D slices etc.)
74
The field of view size can be selected and positioned according to the:
diagnostic task
75
CBCT units have capabilities for scanning a range of:
FOV sizes
76
T/F: You pick the FOV you need and then position the patient in the CBCT unit
False- you position the patient first & then pick the FOV you need according to the area being imaged
77
The _______ needs to be in the selected FOV
area being imaged
78
What is the difference between the PaX-i3D Smart vs. Pax-i3D premium?
Pax-i3D premium has multi FOV- leading to more area being imaged (whole head)
79
If you are wanting to capture a full skull image compared to a small area of teeth you would need:
a larger detector (more expensive)
80
What is the FOV for these images?
8cm x 15cm
81
What is the FOV for these images?
13cm x 15cm
82
What is the FOV for these images? What can this be considered?
26cm x 15cm (Extend FOV)
83
CBCT factors affecting dose:
1. FOV
2. Exposure
3. Voxel
4. Sensors
84
The kv ranges for CBCT based on:
the unit
85
When kV of a CBCT we are talking about:
exposure
86
What kV range between various CBCT units?
75 kV to 120 kV
87
What is the mA ranges between various CBCT units?
7 mA to 20 mA
88
When talking about exposure, ____ is affected by basis image data
time
89
X-ray beam projection scheme shows ______ imaging geometry with the resultant image production
Cone beam
90
In CBCT image production, multiple ______ projections form the _____
basis image; projection data
91
After the CBCT unit forms multiple basis image projections forming the projection data, a ________ is then constructed by an imaging software program
volumetric data set
92
A ______ is constructed by an imaging software program which then displays various ______
volumetric data set; image reconstructions
93
The image reconstructions produced by the imaging software program from the volumetric data set is dependent on the power of the programs as specified by the:
software manufacturers
94
X-ray beam projection scheme shows a :cone" beam imaging geometry with the resultant production of:
a basis image
95
To obtain projected images, the X-ray tube & detector move _____ around the ____
concomitantly; axis of rotation
96
To obtain projected images, the _____ & ____ move concomitantly around the axis of rotation
X-ray tube & detector
97
________ as the machine rotated counterclockwise from position 1 to position 2
two basis-image capture sequences
98
What way does a CBCT machine rotate?
counter-clockwise
99
CBCT scans routinely capture in the range of ____ to ___ basis images per rotational scan
100; 600
100
CBCT scans routinely capture a range of 100-600 ______ per ____-
basis images; rotational scan
101
When a low number of _____ is used, the object is undersampled and the image exhibits streaks along the direction of the backprojected rays
projections
102
How could you fix this, if this was the result of your CBCT scan?
An improved reconstruction is possible when the number of projection angles is increased
103
The number of basis images affects:
1. image quality
2. dose
104
The number of basis images affects the image quality and dose. Explain:
The more basis images captured = the more detailed the reconstruction will be however the more basis images captured= the more radiation the patient is exposed to
105
Smaller voxel size=
better the image because of higher resolution
106
Factors affecting dose include:
1. exposure settings (kV, mA, time)
2. Resolution (voxel size)
3. FOV
107
The smaller the voxel size, the ______obtained
more information
108
Which image is the result of a smaller voxel size?
Image A
109
A voxel size of 0.3mm cubed =
300 micrometers cubed
110
A voxel size of 0.075mm cubed=
75 micrometers cubed
111
Small voxel yields _______ resolution
Higher
112
Small voxel size yield LOWER _____
signal to noise ratio
113
Small voxel size yields _____ radiation dose
high
114
Why might small voxel size after a certain point result in degraded image quality?
Smoothes too much due to Compton scatter (signal to noise ratio)
115
What is the voxel size for larger FOVs?
Greater than or equal to 0.200mm = 200 micrometers
116
What is the voxel size for smaller FOVs? (less than or equal to (5cm x 5 cm)
Less than 0.200mm = 200 micrometers
117
Small voxel yields high resolution but requires _____ ( _____) to capture signal in the greater number of the smaller voxels
more x-ray photons (higher exposure)
118
T/F: Current scanners are not configured for the longer scan times and longer processing times for a large FOV with a small voxel size
True
119
Smaller voxels need more _______ which yields a higher _____
photon signal; radiation dose
120
Sensors are also known as:
detectors
121
A panoramic focal trough is a _____ focal trough
3D
122
Label what kind of image detectors are seen in the CBCT units below:
Left: charge-coupled image intensifier detector
Right: flat-panel detector
123
Label which detector produces the following distortion patterns:
A: image-intensifier detector
B: flat-panel detector
124
Grid type X distortion pattern is a result of:
Image-intensifier detector
125
Grid type Y distortion pattern is a result of:
Flat-panel detector
126
With a grid type X (image intensifier detector) distortion pattern, distortion of the image grid occurs:
When moving away from the center
127
With this type of detector even at more distant areas from the center of the grid there is minimal to no distortion of the grid pattern:
Flat-panel (grid Y)
128
Improved image quality, and higher signal-to-noise ratio are seen with what type of image detector?
Flat pannel
129
What type of image detector results in a lower radiation dose/
CCD image intensifier
130
CBVT:
Cone beam volume tomography
131
DCT:
Dental CT (bad term)
132
MCT:
Micro CT (bad term)
133
3DI:
3D imaging (terrible term)
134
