Fundamentals Of Imaging Flashcards
1
Q
What does CT image best?
A
- subtle fractures or complex fractures
- evaluating degenerative changes
- multiple injuries to both osseous and soft tissue structures can be determined from one imaging series
- evaluation of spinal stenosis
- condition of intervertebral disk
- evaluation of loose bodies in a joint
- less time consuming
- accurate measurements of osseous alignment in any plane
- less expensive
- not claustrophobic
2
Q
What are the general advantages of ultrasound?
A
Low cost portability no contraindications not limited by orthogonal planes continuous modification
3
Q
What are the abnormal characteristics of tendons and ligaments on an ultrasound?
A
Strains: thickening of mixed echogenicity
Ruptures: disruption of structure
4
Q
What are the abnormal characteristics of surface cortical bone on an ultrasound?
A
break in continuity, uneven surfaces
5
Q
What are the abnormal characteristics of muscle on an ultrasound?
A
muscle strain: disruption of fibrous bands
Rupture: retraction of muscle
6
Q
What is considered the gold standard that all new imaging technologies are measured against?
A
Film/ screen radiography
7
Q
Radiolucent is defined as?
A
Easily penetrated by x-rays.
8
Q
Fracture line can be?
A
Transverse
Longitudinal
Oblique
Spiral
9
Q
What is a complete fracture?
A
A fracture in which all vortices of the bone have been disrupted
10
Q
What are some different forms of CT?
A
3D CT
CT myelogram
Cone beam computed tomography
11
Q
The order of radiodensity of body matter:
A
Air (black)
Fat (gray-black)
Water (gray)
Bone (white)
12
Q
MR imaging characteristics for inflammation:
A
T1 low signal intensity
T2 high signal intensity
13
Q
Why can an MRI detect an injury that is not visible on a CT or radiograph?
A
The injury can leave a bone bruise as a “footprint”
14
Q
What is three- dimensional CT?
A
Presents 3D images of body parts that can be rotated in space
15
Q
What is one factor known to reduce error?
A
Communication between the clinical and radiologist
16
Q
General components of a radiologic report:
A
Heading Clinical information Findings Conclusions/ Impressions Recommendations Signature of radiologist
17
Q
What is fluoroscopy?
A
Fluoroscopy is a dynamic or continuous radiographic examination.
18
Q
Evaluation of Alignment:
A
General Skeletal architecture
General contour of bone
Alignment of bones to adjacent bones
19
Q
What are the advantages of MRI over CT?
A
Greater resolution for soft tissue imaging
No radiation
Less risk of missing disease processes
20
Q
what is doppler ultrasound used for?
A
To measure blood flow in an artery or a vein.
Often used to rule out DVT
21
Q
What is a radiograph?
A
A radiograph has been defined for over a century as an x-ray film containing an image of part of a patient’s anatomy
22
Q
Why are stress fractures difficult to diagnose?
A
Because the fracture line or periosteal reaction may not be evident for up to 6 weeks
23
Q
Evaluation of Cartilage spaces:
A
Joint space width
Subchondral bone
Epiphyseal plates
24
Q
What does MRI image best:
A
Display of soft tissue detail
25
Tissue origins used to classify tumors:
```
Bone
Marrow
Cartilage
Nerves
Fat
Fibrous
Unknown
```
26
What is malunion?
Fracture has successfully united but a degree of angular or rotary deformity exists
27
What is slow union?
The rate of union, although slow, may be average or normal given he significant factors involved.
28
What are the ABCS of radiologic analysis?
A: Alignment
B: Bone density
C: Cartilage spaces
S: Soft tissues
29
Two types if trauma that can cause fractures:
Direct and indirect
30
What are the pitfalls of image interpretation?
Errors ! Errors of observation or errors of interpretation.
31
What are the different projections?
Anteroposterior (AP)
Posteroanterior (PA)
Lateral
Oblique
32
The MRI are actually what type of images?
They are slices
33
Direct forces that can cause a fracture:
Tapping
Crushing
Penetrating
34
Radiopaque is defined as?
Not easily penetrated by x-rays
35
What is nonunion?
Fracture fragments fail to unite and the processes of bone repair have ceased completely
36
Salter- Harris classification of epiphyseal fractures:
Type I-V
Rang's Type VI
Ogden's Types VII, VIII, IX
37
What are errors in interpretation?
Errors in interpretation can be linked to the practitioner's failure to link abnormal radiologic signs to relevant clinical data
38
What are disadvantages of ultrasound over MRI?
limited ability to show joint surfaces and interarticular structures
only shows cortical outline
39
What is osteomyelitis?
Result of contiguous dissemination of a pathogen from an open fracture or surgical fixation
40
MR imaging characteristics of muscle:
T1 intermediate signal intensity
| T2 intermediate signal intensity
41
Indirect forces that can cause fractures:
```
Bending
Torsion
Compression + bending
Compression + bending+ torsion
Traction
```
42
What makes a structure hypo echoic?
the structure reflects little energy
43
Categories of skeletal pathology:
```
Congenital
Inflammatory
Metabolic
Neoplastic
Traumatic
Vascular
```
44
Interventional radiology:
Radiologists diagnose and treat disease nonoperatively
45
Why do clinicians need to view diagnostic images?
- A more comprehensive evaluation is obtained
- The information the clinician seeks is often of a different nature from the information the physician seeks and of a different nature from what may be described in the radiologist's report
46
What is avascular necrosis?
Exists when the blood supply to a bone or segment of a bone is compromised, leading to localized bone death
47
What are stress fractures also known as?
Microfractures, fatigue fractures, and insufficiency fractures
48
What is radiodensity?
Radiodensity is the combination of physical qualities of an object that determine how much radiation it absorbs from the x-ray beam.
49
What is the most common disorder of the musculoskeletal system evaluated by radiology?
Trauma: fractures and dislocations makeup the majority of traumatic conditions
50
What are the limitations of MRI?
Length of time needed to produce an image
51
What does T1 imaging provide?
T1 imaging provides images of good anatomical detail, displaying the tissues in a fairly balanced manner
52
What is an ultrasound?
it is a cross sectional imaging method based on sound waves reflected off tissue interfaces
53
Magnetic resonance image:
A cross- sectional imaging technology that uses a magnetic field and radiofrequency signals to cause hydrogen nuclei to emit their own signals, which then are converted to images by a computer
54
How are tumors classified?
By their tissue of origin
55
Views of MR images:
Coronal images are viewed from the front
Axial images are viewed from below
Sagittal images are viewed from left to right for either side of the body
56
What is a big imaging difference between CT/ radiographs and MRI?
Structures that appear bright on radiographs and CT typically appear dark on MRI
57
What is it called when a structure reflects no energy?
anechoic
58
Radiodensities on a CT image:
Dense structures appear white or a light shade of gray whereas less dense structures appear dark
59
Evaluation of bone density:
General bone density
Textural abnormalities
Local bone density changes
60
MRI imaging characteristics of ligament and tendon:
T1 Low signal intensity
| T2 Low signal intensity
61
Life threatening complications of fractures:
```
Hemorrhage (most common)
Fat embolism
Pulmonary Embolism
Gas Gangrene
Tetanus
```
62
What is a fracture?
A fracture is a break in the structural continuity of bone or cartilage
63
What is the contrast used for an MRI?
Gadolinium
64
For patients involved in high velocity injuries the trauma survey will include?
"Cross- table lateral" of the cervical spine
Anteroposterior chest
AP pelvis
Possible additions: CT of the head, cervical spine, thorax, abdomen, and pelvis, with or without contrast
65
How can an MRI potentially detect a stress fracture?
In a T2 weighted image a stress reaction can be seen
66
How is ultrasound used in rehabilitation?
physical therapists employ ultrasound imaging for diagnosing musculoskeletal disorders
67
Other common studies in musculoskeletal imaging:
Contrast- enhanced radiographs
Conventional tomography
Computed tomography
Nuclear imaging
68
What is pseudoarthrosis?
Abnormal condition associated with nonunion. "False joint" may form between the ends and be surrounded by a burial sac containing synovial fluid.
69
What is the purpose of a routine or standard radiographic examination?
To provide the most visualization of anatomy with the least number of radiographs and thus to expose the patient to minimal radiation
70
Why does a comminuted fracture not always have a clear fracture line?
Because it is a fracture with more than two fragments
71
What are the two other shade of gray on an x-ray?
```
Contrast media (bright white outline)
Heavy metals (solid white)
```
72
MR imaging characteristics for stress fractures:
T1 low signal intensity with a dark band
| T2 high signal intensity with a dark band
73
What is delayed union?
Fracture fails to unite in the time frame usually required for union
74
What is T2 imaging valuable for?
Detecting inflammation
75
Healing time frame for no operative extremity fracture:
4-8 weeks
76
What is reduction?
Restoring fragments to their normal an atomic positions
77
What is the difference between and open fracture and a closed fracture?
With an open fracture the skin is perforated regardless of the size of the wound. A closed fracture the skin remains intact
78
What is an incomplete fracture?
Only one portion of the cortex is disrupted
79
What is bone length discrepancy?
Some fracture healing can result in unacceptable shortening of bone length
80
How can interventional procedures be grouped?
Vascular and nonvascular procedures
81
Define decubitus:
It is both a body positioned on a horizontal surface and the use of a horizontal x-ray beam
82
What is the first imaging procedure to be done following the clinical examination?
Conventional radiography
83
What are the advantages of CT over MRI?
```
Less expensive
More common
Faster times
Not as affected by motion
Greater resolution for Cortical bone
```
84
What does "one view is no view" mean?
A single radiograph provides only two dimensions: length and width. The third dimension, depth, is compensated for by viewing a second radiograph projected at a 90 degree angle to the first image.
85
What is an example of interventional radiology?
Catheters, guide wires, needles, cannula, balloons, stents, and other devices are placed under the guidance of imaging to perform procedures that are often alternatives to surgery
86
When will bone fracture?
When the imposed load exceeds the bone's tolerance
87
What are errors of observation?
Errors of observation can be linked to incomplete or faulty search patterns.
88
What is gandolinium?
A paramagnetic metal ion that can be used for regular MRI applications.
89
Different distributions of lesions:
Monostotic- affecting only one bone
Polyostotic- affecting multiple bones or multiple joints
Diffuse- affecting all or nearly all bones or joints
90
What is the fundamental tool of the musculoskeletal radiologist?
Conventional radiography
91
What is primary trauma survey?
When imaging was performed initially in the emergency department
92
What is neuroimaging?
Imaging of the brain, can be described in terms of structural imaging and functional imaging
93
Fracture complications in other tissues:
Arterial injury: small %
Nerve injury: most temporary; serious associated with open fractures
Compartment syndrome: circulation and function of tissues within a closed space are compromised by increased pressure
94
What is radiology?
Radiology is the branch of medicine concerned with radiant energy and radioactive substances including x-rays, radioactive isotopes, and ionizing radiation and the application of this information to prevention, diagnosis, and treatment of disease.
95
Evaluation of soft tissues:
```
Muscles
Fat pads and fat lines
Joint capsules
Periosteum
Miscellaneous soft tissue findings
```
96
What makes a structure hyper echoic?
the structure reflects a lot of energy
97
Upright can denote?
Seated or standing
98
What are the possible results of a routine radiographic examination?
```
Positive
Negative
Negative for one but positive for another
Inconclusive
Wrong
```
99
What is musculoskeletal imaging?
Musculoskeletal imaging is the sub specialty of radiology concerned with the diagnostic evaluation of the musculoskeletal system.
