My Ct Flash Cards
(115 cards)
1
Q
Which of the following terms is not an indication for imaging of the renal arteries
- aneurysms
- stenosis
- kidney transplant
- cysts
A
Cysts
2
Q
Hypertrophy of the facet of a vertebra is known as
A
Spondylosis
3
Q
The total measurement of radiation that has traveled through a pt and falls on a single detector is called
A
Ray sum
4
Q
———— describes a set of rules or directions for getting a specific output from a specific input
A
Algorithm
5
Q
Whole body dose from a partial body exposure is quantified by
A
Effective dose
6
Q
———- takes into consideration the variations in density of the object
A
CTDIw
7
Q
The medium used to measure the light that is emitted from the scintillation crystal is called
A
Photodiode
8
Q
Transmission of data to the computer is completed by the
A
DAS
9
Q
——— occurs when multiple types of tissue are represented by a single voxel
A
Partial volume averaging
10
Q
——- digitally represents a quantity of scanned pt tissue
A
Voxel
11
Q
Pitch does not effect
A
Amount of gap or overlap between slices
12
Q
——— is a measure of blood coagulation
A
PT
13
Q
Prothrombin time (PT)
A
12-15 seconds
14
Q
——- have the same osmolality as blood
A
IOCM—-
iso-osculatory contrast media
15
Q
Ct number for muscle
A
50
16
Q
—- describes the amount of X-ray energy absorbed in a unit of mass
A
Absorbed dose
17
Q
—— accounts for the type of tissue that the radiation is deposited in
A
Effective dose
18
Q
—— approximates the relative risk from exposure to ionizing radiation
A
Effective dose
19
Q
—- is an estimation of the whole body dose equivalent that results form the partial body exposure the pt receives during a duct procedure
A
Effective dose
20
Q
——- is the term used to describe the ability of xrays to ionize a volume of air
A
Exposure
21
Q
Exposure is measured in ——-
A
Roentgens
22
Q
—— is a graphical representation of a ct systems response to a spatial frequency
A
MTF
Modulation transfer function
24
Q
How many different grayscale values can an image have
A
256
25
Q
The patients raw data allows us to generate ——
A
Retrospective image reconstructions
26
MTF measures
Spatial frequency
27
A filtered beam that is more homogeneous is less susceptible to artifacts from a process know as —-
Beam hardening
28
A pitch of —- reduces the table speed for each gantry revolution and can increase image quality
Less than one
29
Ct number for dense bone
3000
30
White matter ct number
45
31
——- is a measure of the size of the smallest object of the smallest object that can be visualized in an image
Spatial resolution
32
The transverse plane is
Perpendicular to the direction of z axis
33
How does contrast flow through the heart
R atrium
R ventricle
L atrium
L ventricle
34
—- does not affect the image contrast or resolution
MAS
35
To calculate CTDI the acquisition must be
Contiguous
36
Filtered back projection uses what type of filter to remove the blurring that occurs with back projection
Convolution
37
Ct pet is utilized to measure the uptake of ————
FDG
38
Image acquisition in a ct pancreas exam typically occurs after ——
35-45 seconds
39
The area of the pt that is exposed to radiation is know as
Dose profile
40
The mathematical process used to create an image in which attenuation data are projected onto a matrix is known as
Back projection
41
The nephrographic phase of contrast enhancement occurs after which of the following
70-90 seconds
42
Spatial resolution within the x and y directions is known as
In plane resolution
43
Which of the following helps to determine the slice thickness of an image
Precollimater
44
Which of the following algorithms reduce image noise when using lower exposures while also preserving image quality
Interactive reconstruction
44
The solid state detector used in modern ct scanners is a
Scintillation detector
45
The connective tissue that surrounds the kidneys is the
Gerota’s fascia
46
In MSCT the number of slices acquired and the thickness of the slices is determined by the
Detector configuration
47
An infection acquired in the hospital is know as
Nosocomial
48
The liver receives 75 % of its blood from the portal vein and 25% from the
Hepatic artery
49
In order to obtain sufficient iodine opacification during a ct examination which of the following concentrations much be present
2-8 mg/ml
50
INR is used to standardize which of the following
Prothrombin time
51
The major and minor calyces make up the
Renal pelvis
52
A ct image has a window level of 300 and a width of 600 which of the following is correct
The ct number will range between 0 and +600
53
The smallest possible slice thickness is determined by the
Smallest single detector channel
54
Gas ionization detectors are primarily used in
3rd generation ct scanners
55
What is stenosis
Narrowing
56
At which level does the sma typically originate
L1
57
Perenteral administration is any ———- method of administration
Non oral
58
The utilization of half-scan reconstruction can improve
Temporal resolution
59
When an upper vertebral body slips over a lower vertebral body this is
Spondylolisthesis
60
Which of the following is measured in millisievert
- absorbed dose
- exposure
- effective dose
- curie
Effective
61
Cardiac diastole corresponds to which of the following
T wave
62
Which of the following is most likely to require images of less than 1mm in thickness
High res chest
63
The excretory phase best shows
-
-
-
Renal pelvis
Ureters
Bladder
(3 min post admin of iv contrast)
64
During a ct urinary track exam puts may be imaged in the prone position to better
Differentiate strokes within the urinary tract
65
True/false
| Ct lung nodule is performed with a reduced technique
True
66
Absorbed dose is reported in
Milligray
67
Which of the following may result in misregistration of pt info
Motion
68
Windowing of a ct image controls
Contrast and brightness
69
Iohexol is a —- contrast material
Non ionic
70
The ability of the ct scanner to show small objects that are close together
Spatial resolution
71
——- is a measure of noise in an image
Standard deviation
72
DLP and CTDI are displayed on CT dose reports
73
Claudication maybe a clinical indication for
CTA runoff
74
The adnexa of the uterus is made up of the
Ovaries and fallopian tubes
75
——- is most likely to be used during a ct enterography exam
Neutral oral contrast
76
—— transmit acquisition data to the computer
DAS
77
ASSIGNING A VALUE TO THE ATtenuation signal that is created by the detector is know as
Linear attenuation coefficient
78
As it relates to the detectors stability is ——
The steadiness of the detectors response to the xrays
79
Directing electrons to tow different areas on the focal spot is referred to as
Flying focal spot
80
Which factor related to spatial resolution requires a 2x sample of the object, compared to the spatial frequency
Sampling
81
FWHM is a measure of
Effective section width
82
—— is the quantity of blood that moves within 100g of brain tissue in a min
Cerebral blood flow
83
At which vertebral level does the spinal cord end
L1-L2
84
When calculating dlp what relationship does scan length have with dose
It is proportional
85
——- is the total amount of exposure for an exam
DLP
86
Of the following which has a direct effect on pt dose
- window width
- mas
- matric
- DFOV
MAS
87
Increasing radiation dose to overcome the penumbra at the edge of the detectors is know as
Overbeaming
88
Which axis indicated width
X Axis
89
Gantry rotation affects ——- resolution
Temporal
90
Multi-segmont reconstruction has a direct impact on which of the following
Temporal resolution
91
Which is a non ionic contrast material
Iohexol
92
The term used to describe a filtration algorithm that removes blurring in an image during back-projection is
Convolution
93
The utilization of half-scan reconstruction can improve which of the following
Temporal resolution
94
Which of the following is not required to be included in the structured dose report
DFOV
95
The number of data channels active and the effective section thickness is know as
Detector configuration
96
Voxels that form a perfect cube are referred to as
Isotropic
97
MinIP is used to display
The minimum attenuation within a voxel
98
The mathematical process that uses data points above and below a slice to reconstruct an image is know as
Interpolation
99
The circle of Willis
- RL anterior cervbral arteries
- anterior communicating art
- RL internal cor art
- RL posterior cerebral arteries
- RL posterior communicating arteries
100
—— uses a convolution filter to remove blurring that occurs with back projection
Filtered back projection
101
What type of viewing allows for the review of large amounts of images quickly and in a continuous loop
CINE
102
The X-ray beam utilized in MDCT is know as
CONE BEAM
103
—— is used to describe the rate that photons pass through an area in a set amount of time
Photon flux
104
Images areas that contain objects with high variations in densities will have
High spatial frequency
105
—— can reduce image noise which helps improve the quality of the image while also reducing pt dose
Iterative reconstruction
106
What imaging plane is parallel to the metatarsals of the foot
Obli
107
Which imaging plane is parallel to the metatarsals of the foot
The oblique axial
108
——- will impact the volume of a voxel when adjustments are made
MPR
109
Transmission of data to the computer is completed by the
DAS
110
Which of the following does CTDI measure
The dose received in a single slive
111
Conversion of data into digital values is completed by the
ADC
112
——- is used to approximate the radiation dose for each section obtained during a helical scan
CTDI vol
113
Normal bun levels
7-20
114
Low oxygen level in the blood
Hypoxemia
115
Arterial systole corresponds to
P wave
