Lecture 1 Flashcards
1
Q
Roles of Imaging in PT Management: (7)
A
- Improve understanding of anatomy
- Improve understanding of pathology, trauma, healing
- Inform interventions
- Help you educate your patients
- Support or refute PT Dx.
- Improve ICD10 coding
- Support PT as practitioners of choice for MS conditions
2
Q
Large osteophyte at talar head
A
Talar beak
3
Q
Fibrous or bony attachment in area of foot- causes pain
A
Talocalcaneal coalition
4
Q
Rare human an atomic variant that usually affects lateral meniscus of knee
MRI used
A
Discoid meniscus
5
Q
When is imaging needed? (4)
What are examples included within these categories?
A
- Trauma: MVA, fall, blunt trauma
- Cancer/malignancy/tumor: hx, age >55, weight loss, non-mechanical pain
- Infection: fever of unknown origin
- Miscellaneous: non-responsive to conservative care
6
Q
American College of Radiology: Appropriateness Criteria
The _______ the rating number, the more appropriate the study is for that patient
A
HIGHER
7
Q
ACR Appropriateness Criteria:
Perform variants _____-_____, then if they refer for x-ray, continue ACR rating
A
Variants 1-3
8
Q
If MRI is not appropriate, then ____ may be more appropriate
A
CT
9
Q
________ are tools used by clinicians to determine likelihood that patient is presenting with given disorder, based on number of variables that have been shown to have predictive ______ in revealing patients most likely to have specific disorders
A
Clinical prediction rules
Validity
10
Q
Canadian C-Spine Rule:
What are the 3 questions?
A
- Any high risk factor that mandates radiography?
- Any low risk factor that allows safe assessment of ROM?
- Able to rotate neck actively?
11
Q
Canadian C-Spine Rule:
What is considered “high risk factor that mandates radiography”
A
Age >65
Dangerous mechanism/paresthesia in extremeties
12
Q
Canadian C-Spine Rule:
What qualifies as low risk factor that allows safe assessment of ROM
A
- Simple rear end MVA
- sitting position in ER
- ambulatory at any time
- delayed (not immediate) onset of neck pain
- absence or midline cervical spine tenderness
13
Q
Canadian C-Spine Rule:
What is meant by active neck rotation?
A
45 degrees L/R
14
Q
Ottawa Knee Rules (5 things)
A
- Age >55
- Isolated patella tenderness
- Tenderness at head of fibula
- Inability to flex knee to 90 deg
- Unable to bear weight immediately after and walk 4 steps in ER
15
Q
Pittsburgh Knee Rule: 3 things
A
- Blunt trauma or fall is MOI and either of following is true:
1. Age <12 or >50
2. Inability to walk 4 steps in ED
16
Q
Ottawa Ankle Rules (4)
A
- Bone tenderness at posterior edge of distal 6cm of tip of medial or lateral malleolus
- Unable both to bear weight immediately after injury and walk 4 steps in ER
- Bone tenderness at base of 5th metatarsal
- Bone tenderness over navicular
17
Q
Pittsburgh Ankle Rules (2)
A
- Age <12 or >50
2. Unable both to bear weight and walk 4 steps in ER
18
Q
AROM after Acute Elbow Injury:
Limited ROM in all directions of flexion, extension, sup/pro predictive of ________.
Sensitivity _____%, Specificity ______%
Individuals with limitation in ____ or ____ directions had no signs of fx in x-ray
A
Elbow fx
90, 92
One or two
19
Q
4 types of imaging modalities
A
- Radiographs/X-rays
- Computed tomography
- Ultrasound
- Magnetic resonance imaging
20
Q
What is the most widely performed imaging exam?
A
X-ray
21
Q
X-rays are emitted and detected in ______, which can generate either film or digital image.
A
Cassette
22
Q
Films are kept on file or in digital archive called _____.
A
PACS (Picture archiving and communications system)
23
Q
X-rays are a form of _____ ______ radiation (discovered in 1895)
A
Ionizing electromagnetic
24
Q
X-rays are produced in tube and beamed out of collimator, which controls ______ and _____ of X-ray field
A
Size and shape
25
X-rays pass through patient and undergo _________
Attenuation
26
Reduction in number of X-ray photons in beam as result of photons interaction with matter and losing energy through either scattering, absorption, or beam divergence is known as _____
Attenuation
27
3 ways X-ray photons lose energy
1. Scattering
2. Absorption
3. Beam divergence
28
Combination of physical qualities of an object that determines how much radiation it absorbs from X-ray beam is _______
Radiodensity
29
4 shades of gray from radiolucent -----> radiopaque
1. Air: black
2. Fat: gray-black
3. Water: gray
4. Bone: white
30
What color is radiolucent
Black- nothing is blocking it
31
What color is radiopaque
Bright white
32
What color is fat on X-ray
Gray-black
33
What color is air on X-ray
Black
34
What color is bone on X-ray
White
35
What color is water on xray
Gray
36
X-ray: ___D seen in ___D
3D, 2D
37
Image of xray is summation of _______
An atomic shadows
38
Radiodensity is function of ____ and _____
Thickness and composition
39
T/F: One view is no view
TRUE
40
5 limitations of radiographic imaging
1. Film quality
2. Sensitivity (not sensitive to subtle pathology)
3. Specificity
4. Appropriateness (inability to adequately visualize soft tissue)
5. Examination errors
41
Pros of radiographs (5)
1. Widely available
2. Inexpensive
3. Doesn't require advanced technologist knowledge
4. Can be performed quickly
5. Portable
42
Cons of radiographs (3)
1. Ionizing radiation
2. Relatively intensive
3. Patient cooperation
43
4 types of radiographic distortion
1. Enlargement
2. Superimposition
3. Elongation
4. Foreshortening
44
What is foreshortening
Occurs when beam strikes object that is not at R angle to beam
45
What is superimposition
One object on top of another on xray
46
What is enlargement (xray)
Anything in front of the expanding beam looks smaller compared to those in the back
47
T/F: it is ok to perform X-rays as often as needed
FALSE- "Because of the cumulative and harmful effects of ionizing radiation, X-rays should only be done when necessary and never as a routine procedure"
48
CT: T/F
| X-ray beam rotates 180 degrees around object
False- 360!
49
CT: provides superior contrast and better visualization of _______ than radiography
Soft tissue
50
CT: T/F
| Not as good for imaging of bone fragments and fractures
FALSE! Better imaging of bone fragments and fxs
51
Dynamic and continuous radiographic examination that provides REAL TIME imaging of physiological function is _____
Fluoroscopy
52
What is a scintigraphy?
Bone scan
53
Bone scan: Injection of polyphosphate and _____ ______ binds to hydroxyapatite found in _____ ______ bone
Radioactive isotope
| Metabolically active
54
What is a bone scan used for? (3)
1. Bone tumors
2. Metastasis
3. Early detection of stress fx
55
What type of imaging is used to see developing baby
Diagnostic U/S
56
Diagnostic U/S is an image created by transmitting ________ into body that reflect off tissues. The intensity of the reflected ______ are then interpreted.
sound waves
| Echoes
57
Ultrasound origins are in ______
SONAR
58
What are the 3 components of diagnostic u/s
1. Pulser
2. Transducer
3. Scan converter and monitor
59
What are the measurements of the pulser (u/s)
2-15 MHz
60
What does the U/S transducer do
Converts electricity to sound
61
How is U/S produced?
Reverse piezoelectric effect
62
What are the beam characteristics of U/S
Converges to focal zone then diverges
63
4 ways U/S sound waves travel
1. Absorption
2. Reflection
3. Refraction- waves transmitted across interface an change directions
4. Scattering
64
How well the surface will reflect the U/S beam is called
Echogenicity
65
U/S: Tissues or interfaces that reflect MUCH energy are ______
Hyperechoic
66
U/S: Tissues and interfaces that reflect LITTLE energy are called
Hypoechoic
67
U/S: Tissues and interfaces that reflect little energy (...thinking should say "no"?)
Anechoic
68
Sound waves reflect off ______ tissue and interfaces between tissue that are dissimilar in ______ and produce _____ images
Hyperechoic
Density
Bright
69
Dx U/S Scanning Planes:
| Longitudinal sonogram results in _____ image
Sagittal
70
Dx U/S Scanning Planes:
| Transverse sonogram results in ______ image
Axial
71
Dx U/S Scanning Planes:
| Structures can be followed through ______
All planes
72
DU/S Advantages: (7)
1. High resolution
2. Low cost
3. Safe
4. Fast
5. Portable
6. Easy comparison
7. Well tolerated
73
D U/S Disadvantages (3)
1. Operator dependent
2. Bone not penetrated
3. Poor imaging of obese
74
T/F: U/S is powerful dx tool for examining musculoskel disorders
TRUE
75
T/F: Dx MS ultrasound does not fit well with orthopedic PT practice
FALSE- it does
76
T/F: U/S substitutes for MRI in evaluating soft tissue injuries such as RTC, Achilles tendon
TRUE
77
T/F: U/S provides biofeedback for transverse abdominus contractions
TRUE
78
Procedure used to evaluate muscle and related soft tissue morphology and function during exercise and physical tasks
Rehabilitative U/S Imaging
79
Measures spatial distribution of protons from H+ atoms in body when excited by radio frequency waves in magnetic field
MRI
80
Signal emitted from MRI is ____ _____ ____
Nuclear magnetic resonance (NMR)
81
2 kinds of NMR used in MRI
1. Free induction decay T2*
| 2. Echo (Spin, Gradient, Multi) T1, T2, PD
82
Repetition time (TR) modifies ______-weighing
T1
83
The longer the TR, the ____ T1- weighing the image is
Less
84
Echo time (TE) modifies the ______-weighing
T2
85
The ____ the TE, the less T2- weighed the image is
Shorter
86
Short TR, short TE
T1-weighted image
87
Long TR, long TE
T2-weighed image
88
Long TR, short TE
PD-weighed image
89
______ has a high intensity signal with T1
FAT
90
____ has high intensity signal with T2
WATER ("H20-T2")
91
What is seen as high intensity with PD weighing
Fat and fluid
92
MRI contrast- evaluates ______ and joint injuries, bone and _____ tumors
Soft tissue, soft tissue
93
MRI: Changes in water content (H+ atoms)common in acute injuries and _____
Chronic inflammatory conditions
94
MRI sequences are used for detecting _______ such as edema, effusions, synovial fluid, tumors, hematoma
Water changes
95
Bright signal from _____ is often hindrance to dx in MR imaging
Fat
96
MRI: More contrast is possible by manipulation of number of variables and by adding contrast medium such as _____
Gadolinium
97
Relative tissue appearance:
| Bone marrow T1, PD, T2
T1 Bright gray
PD Gray
T2 Gray
98
Relative Tissue Appearance:
| Fat T1, PD, T2
T1 Bright
PD Bright
T2 Gray
99
Relative Tissue Appearance:
| Edema/fluid T1 PD T2
T1 Dark
PD Bright
T2 Bright
100
What color are ligaments and tendons on MRI
Dark
101
Fluid-sensitive sequences:
| T2 =
Fat-suppressed T2-weighted
102
Fluid-sensitive sequences:
| PD =
Proton density-weighted
103
Fluid-sensitive sequences:
| What is FSE
Fast spin echo
104
Fluid-sensitive sequences:
| What is short tau/T1 inversion-recovery
STIR
105
MRI Artifact (4)
1. Motion
2. Flow
3. Chemical shift
4. Magic angle
106
What is the "magic angle" of MRI
Can alter look of MRI if at 5 degree angle from view
107
Limitations of MRI (3)
1. Expensive
2. Time consuming
3. False positives
108
3 contraindications to MRI
1. Ferrous metals
2. Implanted devices
3. Fixation devices and total joint components made of ferrous metals
109
What is the Lexicom for Uniform Indexing and Retrieval of Imaging Information acronym?
Radlex (terminology standards for MRI radiologists)
110
Why do MRIs make noise?
Banging is vibration of metal coils of MRI magnet caused by rapid pulses of electricity. The stronger the magnet and stronger the vibrations, louder the banging.
111
In ______ MRI, ear protection is recommended
3T
112
Open vs. closed MRI:
| Measured in ______
Tesla (T)
113
Open vs. Closed MRI:
| 1.5 T is _____
Open
114
Open vs. Closed MRI:
| ______ is standard and closed
3T
115
Open vs. Closed MRI:
| _____ T is used in research
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