Imaging Flashcards
What is the name for the “growth plate” in a child’s bone
Physis
What is T2 MRI best for assessing?
Fluid assessment/soft tissue injuries
What would you use ultrasound for in orthopedics?
Infants
Soft tissue conditions in adults
Guided assistance for injections, biopsies, etc
Why do kids get incomplete fractures
Their periosteum is thicker and more durable which prevents displacement
If a bone is in more than one piece and it’s all over the place what type of fracture
Comminuted
Is x ray good for injuries that are exclusively soft tissue
No
Bone scans are very sensitive for skeletal pathology, but are they specific?
No
How long does an MRI take
45 min
How do we describe the degree of a bone translation or displacement ?
Percentage of how far offset it is
What is a precaution you must take with x-ray and CT?
Radiation exposure. Don’t want to expose pt to any unnecessary radiation
How many body parts can be visualized with a single MRI
One
What is an axial slice?
A horizontal slice that dives superior and inferior
Who gets incomplete fractures?
Pediatric patients only**
Are bone scans good for pregnant women and children?
No. Radioactive
What do claustrophobic patients think about MRIs?
Do not like
Use sedation, or possibly an “Open” MRI machine
What type of salter:
Growth plate is crushed
Type 5
Why do you have to ask the pt if they’ve ever worked as a metal filer before their MRI?>
Foreign bodies in the eye will rip right out
What imaging type has the most sensitivity in the early detection of bone marrow conditions, stress fractures, osteomyelitis, and malignancy?
MRI
What are the contrast mediums used in CT?
Iodine-materials
Barium
Air
What is the least common salter Harris fracture
Type 5
What contrast mediums are typically used in MRI
Gadolinium-based contrast dye
Less likely to bother pts than iodine-based used in CT
What is T1 best for assessing?
Anatomical assessment
What is it called when bones are completely displaced and also overlapping
Bayoneted
What is a coronal slice?
A longitudinal slice that divide anterior and posterior
What population is ultrasound really good for looking at MSK?
Babies because their bones are unossified ***
Is bowing a type of fracture
Yes
Does MRI have radiation
No, it is a magnetic field
What are the 4 parts of a pediatric long bone?
Diaphysis (shaft)
Metaphysis
Physis (growth plate)
Epiphysis (end)
What is the first line imaging modality that is ordered prior to considering more advanced imaging
X-ray
Which has more severe “artifact:”
CT or MRI?
MRI
How long does CT scan take?
5-10 min
Do bone scans give false negatives?
No!
If it’s not there, it’s not there
Are metal products always a contraindication for MRI?
Not always, as there are MRI safe implants, but you need to be careful
What are indication for bone scan/nuclear scintigraphy?
Osteomyelitis
Metastasis
Bone tumors
Occult fractures
What imaging modality is ideal for soft tissue pathology while still good for bone pathology?
MRI
What is the minimum number of views necessary with x-ray?
2
“One view is no view”
Can CT create 3D images?
Yes
What is the limit on pt weight for CT scan?
300-400 lbs
What do you inject before doing nuclear scintigraphy (bone scan)?
A tracer
Radioisotope bound to phosphate
What is meant by an articulate extension?
The fracture line goes into the joint
What is a concern with the contrast dye used in CT?
Some people are allergic to the iodine
Other people’s kidneys cant handle it
What type of salter:
Through growth plate and metaphysis
(Not through epiphyssi)
Type 2
What type of salter:
Fracture goes through metaphysis, growth plate, and epiphysis
Type 4
What is a “pulse sequence” on an MRI
The “setting” of T1 or T2, etc
Which piece of the bone do we talk about when we are describing its angulation or displacement?
The distal piece
In ultrasound, what frequency of sound waves indicates a solid mass?
High
What is bright on a T1 MRI/
Fat
Gadolinium
(Fluid is dark)
Can ultrasound measure motion?
Yes
What is the most common type of salter Harris fracture
Type 2
What type of fracture:
Bowing
Buckle/torus
Greenstick
Incomplete
What is bright on a T2 MRI?
Fat (unless you add “fat saturation”)
Fluid
What are some concerning features you might see on imaging that might make you think of malignancy
Indistinct margins
Soft tissue involvement
Abnormal periosteal reaction
Rapid growth
Pathological fracture
Is CT good for a pregnant woman
No, you don’t want this much radiation on the baby
What can infection look like on x ray
Anything
What is a Sagittal plane/
A longitudinal slice that divides right and left
What are the two parts of adult long bones?
Diaphysis (shaft)
Metaphysis
What is an occult fracture
Very small one
Can CT help you see stages of bone healing?
Yes
Is ultrasound great for evaluating bone?
No, minimal use
What is one of the biggest limitations to ultrasound?
The skills of the provider
Do we classify adult fractures on the Salter-Harris scale?
No, only for skeletally immature patients
What 2 things are unique to pediatric periosteum?
Metabolically more active
Thicker and more durable
What grade of salter:
Fracture goes through growth plate and epiphysis
(Not through metaphysis)
Type 3
Do oral steroids help bones heal
No, big risk for malunion of fracture
What type of imaging is used as a “problem solving tool rather than an initial screening tool?”
MRI
What grade of salter:
Fracture goes straight across the growth plate
Type 1
What type of fracture:
Transverse
Oblique
Spiral
Allusion
Comminuted
Complete
When looking at an axial CT, what view are you getting?***
Looking from the patient’s feet toward their head***
Where do compression fractures usually happen?
The spine
If a pt has lots of metal in area to be imaged, is CT a good choice?
No, metal can cause “flare”
What is really important to find out about the patient before discussing their X-ray?
Age
Gender
Mechanism of injury
How long ago injury happened
Which would be better to visualize on an x ray: muscle strain or ligament tear?
Ligament tear because you can see how the soft tissue affected the bone
What does nuclear scintigraphy/bone scan show you?
Metabolically active bone areas
What is the initial diagnostic modality for MSK complaints?
X ray
How are angulations of bone fragments described?
In degrees
