Medical Imaging Flashcards
(117 cards)
1
Q
Diagram: Identify the image below
A
CT image of left actabular fracture
2
Q
Q: Sensitivity - A negative test means…
A
You definitely don’t have the condition
2
Q
Term: Ability of the x-ray beam to pass through substance to reach the film plate
A
Permeability
2
Q
Diagram: Radiograph coloring review
A
3
Q
Q: What are the ABCs of Radiology?
A
Alignment, Bone Density, Cartilage, Soft tissue
3
Q
Term: Atomic nuclei allign in an electromagnetic field
A
Resonance
4
Q
Q: How are lateral view named?
A
For the side closer to the film plate
4
Q
Content: 3 parts of soft tissue
A
- Gross size of musculature
- Outline of joint capsules
- Periosteum
5
Q
T/F: A radiograph is simply a representation of the radiographic densities of anatomical structures
A
True
5
Q
Diagram: Identify the problem
A
Metastic bone lesion (from primary lung cancer)
6
Q
Q: What is the error rate in radiological interpretation (by radiologists and radiology residents)?
A
May be as high as 20-40%
6
Q
Q: High object radiodensity results in _____________ radiography density on the film, thus the object appears ________.
A
Decreases, whiter
6
Q
Term: Maximized by positioning patient so structure of interest is closest to film plate
A
Detail
6
Q
Q: How does an MRI generate an electromagnetic field?
A
Uses pulses of radiofrequnecy and a strong external magnet
7
Q
Term: How long resonating protons remain in phase following a RF pulse
A
Transverse magnetization (T2)
8
Q
Defn: Errors of interpretation
A
The injury is there but the radiologist misses it. Ex. Fracture is there but is not seen
9
Q
Diagram: Identify the problem
A
Osteoarthritis of the left hip, with joint collapse
10
Q
Q: What gives an x-ray image with the most detail and least distortion?
A
Have the part of interest as close to the film or plate as possible
11
Q
Q: What produces a radio frequency signal that can be captured and processed into an MRI image?
A
The release of resonant energy
12
Q
Term: Clarity of the image
A
Geometric qualities
13
Q
Defn: Contrast enhancement
A
Injection or ingestion of radiocontrast medium prior to radiographic study
15
Q
T/F: diagnostic imaging and PT guides and informs the PT’s treatment plan.
A
True
15
Q
Content: 3 disadvatnages of MRI
A
- Relatively low specificity
- Expensive
- Contraindicated if pt. has ferrous metal implant or exposure
16
Q
Q: What are the 4 advantages of conventional radiographs (x-rays)?
A
- Time and cost efficient
- Non-invasive
- Low risk
- Good for screening
17
Term: Objects or structures further from the film appear larger than closer points
Magnification
18
Q: What is the first order diagnostic modality?
Conventional radiographs or x-rays
18
Q: What color is the exposed film in radiographic images?
Dark
19
T/F: With interpretation, insignificant findings may prove significant, while significant findings may prove insignificant.
True
20
Content: The 4 parts of alignment
1. Gross bone size
2. Number of bones
3. Shape and contour of cortical outline
4. Joint position and alignment
21
T/F: In x-rays, one view is no view.
True, in terms of interpretation. X-rays are 2D images, need more than one image to reconstruct into 3D
22
T/F: Diagnostics are the tools and are the answer.
False: they are a tool, NOT the answer.
23
Q: What can a PT offer when interpretation is difficult for even the specialist? (3)
1. Managing care 2. Directing imaging 3. Relating imaging studies to clinical evaluation
24
T/F: Diagnostic findings, including imaging, must be used in the context of clinical presentation.
True
24
Defn: True positive
Test detects something that is really there
26
Defn: False positive
Test detects something that is not really there
26
Defn: Specificity
A test's ability to identify a true negative
27
Q: What is the least radiodense stubstance in the body?
Air
28
Diagram: Identify the problem
Biconcave "fish" vertebrae, indicative of osteopenia
28
Diagram: CT Basics
29
Diagram: Identify the problem
Osteonecrosis of femoral head, femoral head begins to flatten
31
Defn: Errors of observation
The image doesn't look like what you think it is Ex. Fracture doesn't show up
33
Term: Reduced strength or density of the x-ray beam as it passes through a medium
Attenuation
34
Diagram: Identify the problem
Fat pad or "sail" sign: note faint density change at arrows as edema pushes fat pad out of fossa
36
Defn: False negative
Test detects nothing, but there is something there
36
Q: Given that HIV blood tests are very sensitive, what can you assume about the presence of the virus from a negative test?
That the test will rarely come up negative is the virus is present - SNOUT
37
T/F: Ortopedic hardware is ferromagnetic, however surgical clips and pacemakers are safe during an MRI.
False, flip it
38
Term: How long it takes protons to relax back to resting state following a RF pulse
Longitudinal magnetization (T1)
39
T/F: The radiodensity of an object is directly related to the radiodensity (amount of blackening) on the radiograph.
False: inversely
41
T/F: Diagnostic imaging and PT improves the PT/physician communication.
True
42
Diagram: In the image below label each line
Red = anterior vertebral line
Blue = posterior vertebral line
Green = spino-laminar line
Orange = posterior spinous line
44
Term: Refers to a test's ability to identify a true negative
Specificity
44
Q: With ________ MRI, tissue enhancement is ______________ to blood flow to the tissue.
Contrast, proportional
45
Q: What acronym is helpful for specificity?
SPIN Specificity, Positive, Ruled In
45
Diagram: Identify the problem
Left intertrochanteric and subtrochanteric hip fractures
46
Term: visibility of the image
Photographic qualities
47
Term: also known as sharpness or resolution
Detail
48
Q: What are the 2 advantages of CT?
1. Sensitive and specific for fracture
2. Useful for rapid assessment of brain or neurologic injury
49
Q: By what percent was diagnostic imaging reduced when military PT's were given the ability to order images.
50%
51
Q: List the substance that represents the color on radiograph (shown below) from darkest to lightest.
1. Air
2. Fat
3. Water
4. Bone
5. Contrast Media
6. Heavy Metals
52
Table: Fill in the table below
53
Term: amount of blackening on the radiograph dependent on distance, time, and current
Density
55
Term: Image appears shorter and wider than the actual object or structure
Foreshortening
57
Q: What is the main disadvantage of conventional radiographs?
They may be normal when a pathology actually exists
58
Q: Given that home pregnancy tests are very specific, what can you assume about the presence of a pregnancy from a positive test?
That a positive test is almost always due to pregnancy - SPIN
59
Q: What are the 3 disadvantages of CT?
1. Radiation exposure
2. Discriminates density, but limited in precise histologic differences
3. Small volume of tissue image as a uniform shade of gray
60
T/F: Diagnostic imaging and PT adds nothing to the comprehensive PT eval.
False: enhances
62
T/F: PT's should be independently interpreting imaging results.
False
63
Term: Refers to a test's ability to identify a true positive.
Sensitivity
64
Q: During an MRI, nuclei realign to their _________ state when the field is \_\_\_\_\_\_\_\_\_, release _________ energy.
Resting, removed, resonant
65
Table: Fill in the table below
66
Term: Usually occurs due to distance between beam source, patient, and image receptor, and from alignment and positioning issues
Distortion
66
Content: 4 parts of cartilage
1. Joint space width
2. Subchondral bone
3. Joint margins (smoothness)
4. Epiphyses and growth plates
69
Diagram: Identify the problem
"Teardrop" fracture of 2nd cervical vertebrae
71
Term: differences between adjacent tissue densities
Contrast
72
Term: easily penetrated by x-rays - i.e. low attenuation
Radiolucent substance
73
Diagram: Identify the type of MRI image.
T2 image of a herniated lumbar disk
75
Defn: True negative
Test detects nothing and nothing is there
76
T/F: MRI images are based on two different processes of proton realignment.
True
77
Term: X-ray absorption capacity, based on substances composition, density, and thickness
Radiodenisty
78
Q: Specificity - A positive test means...
You definitely have a condition
79
Q: What are the 3 common radiograph names?
anterioposterior (AP), posterioanterior (PA), Lateral/oblique
80
Diagram: Identify the contrast enhancement
Barium swallow
81
Diagram: X-ray Basics
82
Diagram: Identify the problem
Compression fracture of 4th lumbar vertebrae
83
Q: What is one thing to be careful of when viewing radiographs?
The identification letters may appear backward or upside down
84
Content: 4 advantages of MRI
1. Good sensitivity
2. Images soft tissue well
3. No radiation
4. Little distortion as images are obtained in one plane
86
Term: Not easily penetrated by x-rays - i.e. high attenuation
Radioopaque substance
87
Q: How are radiographs named?
For the beam directions relative to the patient/patient position
88
Content: Computed tomography basics (4)
1. Uses x-ray attenuation to produce cross-sectional images
2. X-ray tube and film move about a fulcrum
3. Provides detailed anatomical imaging of bone
4. Travserve images are read from the bottom looking up
89
Q: In what ways can MRI contrast be delivered into the pt.'s system?
IV or intra-joint injection
91
Q: What contrast media is typically used?
Barium sulfate (in swallow studies)
92
Diagram: Identify the image below
3D image of tibial plateau and proximal fibular fractures
93
Defn: Sensitivity
A test's ability to identify a true positive
94
Content: 4 parts of bone density
1. Cortical margins dense, lower density in cavity
2. Weight bearing should be higher density
3. Osteoporosis is suggested by low contrast - "washed out"
4. Sclerosis or arthritis will appear as a brighter white
95
Q: What acronym is helpful for sensitivity?
SNOUT Sensitivity, Negative, Ruled Out
97
Diagram: Identify the type of MRI image
T1 image of right hip chondrosarcoma
98
Diagram: Idenifty the type of MRI image
T2 image of tibial plateau and femoral condyle contusion
99
Content: Functional MRI (2)
1. Based on increased BF that accompanies cerebral activity
2. Uses magnetic properties of deoxyhemoglobin as an endogenous contrast agent
100
Content: DEXA (4)
1. Gold standard for body composition
2. Measure bone density
3. Determines density based on difference between absorption of beams
4. Radiation exposure approx. = to a flight from NYC to LA and back
101
Content: Nuclear Medicine (3)
1. Uses radiopharmaceuticals for diagnosis, therapy, and reserach
2. Radiopharmaceuticals are radioactive tracers that are absorbed according to the metabolic properties of the tissue
3. Detection of the location and concentration of radioactive elements is used to produce an image
102
Content: Types of Nuclear Medicine (4)
1. SPECT
2. PET
3. SPECT or PET in combo with CT
4. Radionuclide scintigraphy or bone scan
103
Content: Radionulcide scintigraphy (3)
1. Labeled methylene is injected, scanning occurs 2-3 hours following injection
2. High uptake = increased bone activity or mineral turnover
3. Modality of choice for detecting stress fractures and metastatic bone disease
104
Content: 3 advatanges of radionuclide scintigraphy
1. Highly sensitive for early bone and joint disease
2. Fast
3. Reasonable cost
105
Content: 2 disadvantages of radionuclide scintigraphy
1. Poor specificity
2. Easily influenced by osteoblastic activity or BF of any etiology
106
Diagram: Idenifty the type of image
Radionuclide scintigraphy - metastatic prostate cancer
107
Content: Ultrasonography (4)
1. Images produced by sound waves
2. Tissues have unique acoustic qualities
3. Useful for OBGYN and musculoskeletal tissue
4. Can be used with activity
108
T/F: Ultrasound is operator independent, and does not require practice to have good technique.
False
109
T/F: Ultrasound is included in the PT practice act, but should only be used to confirm diagnosis.
True
110
Q: ____________ \_\_\_\_\_\_\_\_\_\_\_\_ are generally the first order modality.
Conventional , radiographs
111
Q: ______ is used to visualize complex anatomy
CT
112
Q: ________ is used to assess soft tissue.
MRI
113
Content: 3 parts of a trauma survey
1. Diagnose and evaluate fracture or disloaction
2. Match MOI to clinical presentation
3. Assess treatment and monitory healing
114
Q: What types of images are typically taken for a trauma evaluation? (3)
1. Lateral chest
2. AP chest
3. AP pelvis
115
Diagram: Identify the following clinical decision rule;
Sensitivity \_\_\_\_\_\_, Specificity \_\_\_\_\_\_
Pittsburg Decision Rule for Knee Trauma
99%, 60%
116
Diagram: Identify the following clinical decision rule;
Sensitivity \_\_\_\_\_\_, Specificity \_\_\_\_\_\_
Ottowa Knee Rule
97%, 27%
117
Diagram: Identify the following clinical decision rule;
Sensitivity \_\_\_\_\_\_, Specificity \_\_\_\_\_\_
Ottowa Ankle and Foot Rules
100%, 40%
118
Diagram: Identify the following clinical decision rule;
Imaging Guidelines for Actue LBP
