Musculoskeletal imaging Flashcards
What are some diagnostic imaging techniques (5)
- X-ray
- MRI
- CAT
- Ultrasound
- Bone scan
What is the x-ray film that contains the image of the patient called
Radiograph
Prior to the 1970s what were the only imaging technique available
X-rays
What does centralization mean
Pain goes from referred to the actual area of injury
Who discovered x-rays
Wilhelm Roentgen
When were x-rays discovered
1895
What is another name for x-rays
Roentgenograph
True or False:
X-rays are a print not negatives
False
X-rays are a form of what
Electromagnetic radiation
True or False:
X-rays cause ionization of silver atoms on film
True
What are the positions x-rays can be taken in (4)
- AP
- PA
- Lateral
- Oblique
What do lateral x-rays show
Facet joints
What do oblique x-rays show
Intervertebral foramen
What are the ABCs of x-rays
Alignment
Bone
Cartilage
What do you use to read an x-ray
View box or illuminator
Which way do you place the radiographs on the view box
As if the patient were facing the person viewing the film
What are the 6 things seen on x-rays that are osteoblastic
- Radiopaque
- Opacity
- Sclerosis
- Hypertrophic bone
- Increased radiodensity
- Blastic lesion
What does radiopaque mean
Beam didn’t pass through completely
What is opacity
Whiteness
What is sclerosis
Excessive formation
What are the 5 things seen on x-rays that are osteoclastic
- Radiolucent
- Lucency
- Osteopenia
- Decreased radiodensity
- Lytic lesion or lysis
What is radiolucent
Beam passes through
What is radio lucent
Black
What effects radiodensity
Greater atomic weight absorb more of the x-rays and thickness of the material
What does air/gas look like on an x-ray
Very black or black
What does soft tissue/fat look like on an x-ray
Relatively dark, gray-black
What does water look like on an x-ray
Gray
What does bone look like on an x-ray
Relatively white
What do metals look like on an x-ray
Bright white
When looking at x-rays and examining bone what should you look for (6)
- Density
- Fracture
- Tumor
- Infection
- Foreign body
- Anomaly
When looking at x-rays and examining joints what should you look for (4)
- Foreign body
- Arthritis
- Dislocation
- Fracture
When looking at x-rays and examining soft tissue what should you look for (5)
- Edema
- Hemorrhage
- Masses
- Calcifications
- Foreign body
True or False:
If the physician didn’t tell the patient what the x-ray means the PT should
False
True or False:
Contrast can be both radiopaque or radiolucent
True
What is fluoroscopy
Injection of contrast to image
What is fluoroscopy used for most commonly
Epidural placement
What is an arthrography
Injection of contrast into joint space
What is a myelography
Injection of contrast into muscle
Are myelographs still popular
NO
Why aren’t myelographs not popular anymore
They cause severe headaches and nausea
What are computed tomographs used for
Image a cross sectional slice of the body
How do CTs work
They use x-ray beams which move through an arc 360 degrees aroud=nd a patient
What does each slice of a CT usually measure
.3-1.5 cm
What can CTs evaluate (6)
- Bone
- Soft tissue
- Tumors
- Fractures
- Intraarticular abnormalities
- Bone mineral analysis
True or False:
MRIs involve ionized radiation
False
What do MRIs utilize
Radiofrequencies of tissues within a magnetic field
True or False:
Ferrous metals can contraindicate MRIs
True
What is an MRI
Extremely powerful magnetic field coils, radio wave transmitters and radiowaves, and powerful computer
1 tesla equals what
10000 times magnetic strength of the earth
Where is the patient positioned during an MRI
The bore of the magnet
True or False:
The magnet is superconducting and must be cooled to 4 degrees K
True
What does the magnetic field cause
Certain alignment of atomic nuclei with the field
What do the radiowaves being turned n cause
A shift in the direction of the body’s magnetic field
What happens when the radiowaves are turned off
The atoms return to their original magnetized state
What creates the image in an MRI
The resonant energy which is released
What is the resonant energy called
A signal
True or False:
Each tissue in the body gives off the same signal not matter the location in the bore of the magnet or the chemical composition
False
T1 weighting MRIs show what
Anatomy
T2 weighting MRIs show what
Pathology (water)
What color is water in a CT/X-ray, T1 MRI, and T2 MRI
CT/X-ray: Gray
T1: Dark
T2: Bright
What color is air in a CT/X-ray, T1 MRI, and T2 MRI
CT/X-ray: Black
T1: Dark
T2: Dark
What color is fat in a CT/X-ray, T1 MRI, and T2 MRI
CT/X-ray: Black
T1: White
T2: Gray
What color is bone cortex in a CT/X-ray, T1 MRI, and T2 MRI
CT/X-ray: White
T1: Gray-black
T2: Dark gray
What color is bone marrow in a CT/X-ray, T1 MRI, and T2 MRI
CT/X-ray: Gray
T1: Bright
T2: Gray
What Are T1 weighted MRIs good for
Anatomy
What are T2 weighted MRIs good for
Pathology
Why are T2 weighted MRIs good for pathology
Because lesions are usually water based
How do nuclear scans work
Isotopes are attached to certain physiologic molecules and are absorbed by the afflicted tissue then imaged
Nuclear scans have high specificity or sensitivity for inflammation
sensitivity
What does sensitivity mean
Measure true positives so if it is negative it can be ruled out
What is the purpose of ultrasounds
To see contractions of muscle in real time
How do ultrasounds work
High frequency sound waves create an image of living tissue
Are ultrasounds harmful
Heck not!!! That is why the are used for viewing bebes
How do myelograms work
Contrast is injected into the subarachnoid space and mixes with CSF to produce a column of radiopaque fluid
What are myelograms used for
To see where nerve is impinged or damaged
What are the side effects of myelograms
Severe nausea and vomitting
What is the mortise of the ankle
joint space between the tibia, fibula, and talus
