Final Exam Flashcards
1
Q
ROI means
A
region of interest
2
Q
Smallest unit of space on an image is ac called
A
pixel
3
Q
Gamma rays ..
A
can be used to produce images
4
Q
Calcification of an organ will appear
A
whiter
5
Q
2 bit image will have how many grayscale shades?
A
4
6
Q
Air in an x-ray will appear
A
black
7
Q
X-rays are most often used to provide information on
A
structure
8
Q
An image process in which the minimum and maximum pixel intensities between neighboring pixels are averaged to make a new image is called
A
Gaussian smoothing
9
Q
CT scans are composed of multiple xrays called
A
tomographs
10
Q
A ramp edge of an image has
A
a smooth transition from one pixel value to another
11
Q
Grayscales are stored in the computer as
A
numbers
12
Q
An imaging TIFF is an
A
image file storage method
13
Q
The wavelength of light that can be seen by the human eye is
A
400-700 nm
14
Q
A saturating color is
A
all one wavelength
15
Q
A method of imaging that can analyze function is
A
PET
16
Q
Pixel noise in an image
A
describes differences in pixel values that are not related to anatomy or function
17
Q
If the pixels in an image are small, the image is likely to look
A
fine
18
Q
The best tissue to be analyzed for structural changes with X-ray would be
A
bone
19
Q
Which method of storing color information in an image relies on primary colors?
A
RBG
20
Q
A Gaussian blur is a type of
A
smoothing
21
Q
The wavelength of photons from X rays differ from visible light in that they are
A
shorter
22
Q
A ramp edge is defined as
A
a smother transition from one set of pixel values to the next
23
Q
The first person credited with discovering X-rays was
A
roentgen
24
Q
Penetration of Xray determines
A
depth of tissue that can be imaged
25
A complete CAT scan of abdomen with current technology requires
less than 30 seconds
26
An image with high contrast will have
large differences in pixel values
27
X rays rely on photons that are
absorbed and transmitted
28
When imaging with x rays which one of the following tissue types is not well differentiated?
cartilage
29
A bony disease that is not well imaged in X rays is
osteoporosis
30
X rays are not good for identifying
injuries to knee growth plate
31
Ionization is the
untransmitted photons transferring energy to cells
32
A CT image is different from plain X ray in that CT
allows 3D reconstruction of tissue and has better contrast resolution
33
In CT, what part of the equipment rotates?
x ray beam
34
In imaging, a kernel is a
filter for CT scans
35
Multiplanar reconstruction means that
images are reconstructed in a different axial orientation than they were captured
36
Anaphlylactic reactions are infrequently noted during
CT with contrast dye
37
A hemorrhagic stroke in a CT scan appears
white
38
Which typically causes less radiation to be absorbed by the body?
CT scan
39
In an Xray, bone cancer will appear
less dense than surrounding tissue
40
Differences in pixel values that are not related to the anatomy or physiology are referred to as
noise
41
Medical imaging techniques that provide structural information include
ultrasound, X rays, CT
42
High spatial resolution can be lost by
movement of the patient
43
Ionization can damage cells predominantly by
damaging DNA
44
Images captured from the same location but a different time must be registered in order to make a proper comparison. That registration is called
intramodal registration
45
When images are sent to a distant site for interpretation, privacy regulations are followed that coincide with
the facility that captured the image
46
Grayscale level is determined by
numerical pixel value
47
Tomosynthesis is best used to image
breast
48
A sagittal plane cuts the body from
right to left
49
The organization responsible for the regulations about image storage and patient privacy is the
Medical Imaging and Technology Alliance
50
If ionizing radiation from an Xray is insufficient
background noise will be too great
51
Tc-99m is excellent at differentiating
necrotic from healthy tissue
52
Which of the following has the lowest risk level to the patient?
US
53
A thin transducer head will transmit a
high frequency sound wave
54
One method to observe drug activity is by
PET
55
The time it takes for a radionucleotide to reach a value of 0.5 is called the
half-life
56
Edge detection processing would be most important when analyzing the
size of a prostate tumor
57
In a typical US image, a mass of dense material will appear
black
58
The best method used to determine the function of the kidneys by monitoring the clearance of a substance through the kidney is
PET
59
Water found in the body, such as in the bladder is best imaged using
T2 MRI
60
The intensity of an MRI is measured in
Teslas
61
Which instrument can erase information on a patients credit card?
MRI
62
Superconducting MRI instruments are different because their magnets
are bathed in liquid helium to keep them cool
63
Aneurysms are best imaged with
MRI
64
Radionucleotides are often produced at a large hospital because
they have a short duration
65
Steady-state noise can be minimized in most US images by
digital filtering
66
Which imaging technique is contraindicated for people with cochlear implants?
MRI
67
TC-99m labels
RBC
68
Noise associated with signal-to-noise ratio in US is related to
scatter
69
The imaging technique that is based on magnets is
MRI
70
Nuclear medicine was first developed for diagnosis of disease in which organ?
thyroid
71
The most common technique to diagnose cancer is
PET
72
In order to obtain an image, sonography uses
soundwaves
73
What does a PET scan best reveal?
cellular activity
74
Which imaging technique has resolution up to 1 mm in 3D?
MRI
75
The rate at which an excited nucleus returns to a more stable state is called the
decay
76
A method of measuring brain function without contrast or radiation is
fMRI
77
A limitation of fMRI is the
loss of resolution
78
The tracer FDG is used with which of the following techniques?
PET
79
Tissues and organs have a signature pattern of US
scatter
80
One of the most important aspects of obtaining a clear image for US is to
match the type of transducer with the type of imaging that needs to be done
81
Acoustic impedence is the
resistance for a sound wave to penetrate tissue
82
The specific type of US imaging that uses reflected sound waves is called
pulse echo imaging
83
Low frequency US beams are superior to high frequency beams in
tissue penetration
84
The following technique vies metabolically active cells
PET
85
Which physician is qualified to interpret PET?
radiologist
86
Resolution of US image and the attenuation of the US beam energy depends on the
wavelength and frequency of the sound wave
87
When a proton returns to its resting state it is called
relaxation
88
Dense tissue such as a tumor will be bright using
T2 MRI
89
An imaging technique that utilizes protons is called
MRI
90
The most expensive imaging instrument is
MRI
91
Adipose tissue is best visualized as bright tissue when using
T1 MRI
92
The basic unit of measure for the activity of a quantity of radioactive material is a
Curie
93
Duplex scanning is done with which mode of imaging?
US doppler
94
High frequency wavelengths are superior to low frequency for
image resolution
95
Spin-Spin relaxation time is associated with
T2 MRI
96
Which technique uses radioactive compounds for imaging?
Nuclear imaging
97
Which system must move to collect a picture for each projection angle?
SPECT
98
A technique to measure brain activity based on changes in blood flow is
fMRI
99
A possible noise artifact of US that is not found in other imaging techniques like CT scans is
shadows
100
A limitation in obtaining good US images of the abdomen is
obesity
101
Positive contrast media
has increased absorption of xrays and shows up white on film
102
Negative contrast media
less absorption of xrays and shows up black on film
103
Positive contrast media examples
anything iodinated
104
Negative contrast media examples
gas like air or CO2
105
Procedure for oral contrast test
fasting for several hours and drink chalky substance (barium sulfate) or have air/gas through a nasogastric tube or drink effervescent tablets
106
Typical components used for oral contrast media
barium sulfate
gastrografin (iodine)
sodium bicarbonate
107
VFSS from patients point of view
patient placed next to xray machine and eat/drink barium filled food or drink. Position head and neck in different swallowing variance.
108
Common fixatives and stains
formaldehyde or paraformaldehyde
mercurial
picrates
oxidizing agents or alcohols
109
Most common stain
Hematoxylin and Eosin (H &E)
110
Massons Trichrome staining
stains collagen and other fibrous molecules a deep blue, stains cells red
111
Weigert's elastic stain
stains elastic fibers in extracellular matrix
112
Silver stains
stains neurons
113
Wrights stain
stains RBCs red or pink
| stains nuclei purple
114
Periodic acid-schiff stain
stains glycogen and used for basement membranes (blue)
115
Schmorl's method
stain melanin in skin
| used for skin cancers
116
Antibody staining
specifically binds to a protein
| tagged with fluorescent or non-fluorscent probe
117
Bone tissue in T1 appears.. T2? CT?
dark
dark
white
118
Air appears... in T1, T2? CT?
dark
dark
dark
119
Fat appears ... in T1, T2, CT?
bright
dark
dark
120
Water appears... in T1, T2, CT?
dark
bright
dark
121
Gray brain matter appears ... in T1, T2, CT? White matter?
gray=gray
intermediate
intermediate
white=white (T1)
122
Infarct appears .. in T1, T2, CT?
dark
bright
dark
123
Tumor appears.. in T1, T2, CT?
dark
bright
dark
124
MS plaque appears ... in T1, T2, CT?
dark
bright
dark
