Medical Imaging Flashcards Preview

PTRS 746 Exam 1 Combined and Randomized > Medical Imaging > Flashcards

Flashcards in Medical Imaging Deck (117):
1

Diagram: Identify the image below 

Q image thumb

CT image of left actabular fracture

2

Q: Sensitivity - A negative test means...

You definitely don't have the condition

2

Term: Ability of the x-ray beam to pass through substance to reach the film plate

Permeability

2

Diagram: Radiograph coloring review

A image thumb
3

Q: What are the ABCs of Radiology?

Alignment, Bone Density, Cartilage, Soft tissue 

3

Term: Atomic nuclei allign in an electromagnetic field

Resonance

4

Q: How are lateral view named?

 

For the side closer to the film plate

4

Content: 3 parts of soft tissue

1. Gross size of musculature

2. Outline of joint capsules

3. Periosteum 

5

T/F: A radiograph is simply a representation of the radiographic densities of anatomical structures

True

5

Diagram: Identify the problem 

Q image thumb

Metastic bone lesion (from primary lung cancer)

6

Q: What is the error rate in radiological interpretation (by radiologists and radiology residents)?

May be as high as 20-40%

6

Q: High object radiodensity results in _____________ radiography density on the film, thus the object appears ________.

Decreases, whiter

6

Term: Maximized by positioning patient so structure of interest is closest to film plate

Detail

6

Q: How does an MRI generate an electromagnetic field?

 

Uses pulses of radiofrequnecy and a strong external magnet

7

Term: How long resonating protons remain in phase following a RF pulse

Transverse magnetization (T2)

8

Defn: Errors of interpretation

The injury is there but the radiologist misses it. Ex. Fracture is there but is not seen

9

Diagram: Identify the problem

Q image thumb

Osteoarthritis of the left hip, with joint collapse

10

Q: What gives an x-ray image with the most detail and least distortion?

Have the part of interest as close to the film or plate as possible

11

Q: What produces a radio frequency signal that can be captured and processed into an MRI image?

The release of resonant energy

12

Term: Clarity of the image

Geometric qualities

13

Defn: Contrast enhancement

Injection or ingestion of radiocontrast medium prior to radiographic study 

15

T/F: diagnostic imaging and PT guides and informs the PT's treatment plan.

True

15

Content: 3 disadvatnages of MRI

1. Relatively low specificity

2. Expensive

3. Contraindicated if pt. has ferrous metal implant or exposure 

16

Q: What are the 4 advantages of conventional radiographs (x-rays)?

1. Time and cost efficient

2. Non-invasive

3. Low risk

4. 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

Q image thumb

Biconcave "fish" vertebrae, indicative of osteopenia

28

Diagram: CT Basics

A image thumb
29

Diagram: Identify the problem 

Q image thumb

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 

Q image thumb

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 

Q image thumb

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 

Q image thumb

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.

Q image thumb

1. Air

2. Fat

3. Water

4. Bone

5. Contrast Media

6. Heavy Metals

52

Table: Fill in the table below 

Q image thumb

A image thumb
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

Q image thumb

A image thumb
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 

Q image thumb

"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.

Q image thumb

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

Q image thumb

Barium swallow

81

Diagram: X-ray Basics

A image thumb
82

Diagram: Identify the problem 

Q image thumb

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 

Q image thumb

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

Q image thumb

T1 image of right hip chondrosarcoma 

98

Diagram: Idenifty the type of MRI image

Q image thumb

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

Q image thumb

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 ______

Q image thumb

Pittsburg Decision Rule for Knee Trauma

99%, 60%

116

Diagram: Identify the following clinical decision rule; 

Sensitivity ______, Specificity ______

Q image thumb

Ottowa Knee Rule

97%, 27%

117

Diagram: Identify the following clinical decision rule; 

Sensitivity ______, Specificity ______

Q image thumb

Ottowa Ankle and Foot Rules

100%, 40%

118

Diagram: Identify the following clinical decision rule; 

 

Q image thumb

Imaging Guidelines for Actue LBP