week 2: diagnostic imaging Flashcards
which type of imaging allows for appreciation of basic bony anatomy?
radiography
radiopaque material is _____ (more/less) dense and shows up ___ (what color)
more
white
radiolucent material is _____ (more/less) dense and shows up ___ (what color)
less
black
which type of imaging has excellent demonstration of cortical bone and a high sensitivity to variance in density of tissues?
CT
which type of imaging has the highest dose of radiation?
CT
which imaging would be used after an upper C spine trauma?
CT
which type of imaging has a good sensitivity to metabolism of bone?
bone scan (scintigraphy)
which type of imaging would be good to view cancer mets to bone or stress fractures?
bone scan
which type of imaging has an excellent demonstration of SOFT TISSUES & bone marrow?
MRI
does MRI have radiation?
no
what shows brightest on a T1 weight image (MRI)?
fat
what shows brightest on a T2 weight image (MRI)?
water
which type of MRI would be used to asses swelling?
T2
which type of MRI would be used to plan for a complex surgery?
T1
if contrast is added to joint space for an MRI, what is the image called?
magnetic resonance arthrogram (MRA)
which type of imaging has a good demonstration of soft tissues and allows real-time dynamic imaging?
ultrasound
what is the main limitation of ultrasound?
limited view of deeper structures
hyperechoic material on an ultrasound shows up ____ (color) and is ____ dense
white
more
ex: bone, tendon, ligament, nerve, muscle
hypoechoic material on an ultrasound shows up ____ (color) and is ____ dense
dark
more
ex: nerve, fat
hyperechoic material on an ultrasound shows up ____ (color)
black
ex: blood vessel, cyst
which type of imaging is suited for serial testing and useful for diagnosis and monitoring? (mostly used for bone density)
DEXA
osteoporosis has a T-score of
< -2.5 std
osteopenia has a T-score of
-1.0 - -2.5
criteria for Pittsburgh Guidelines for Knee Trauma
MOI of fall or blunt trauma
age <12 or >50 –> x-ray
if no to above, inability to take 4 steps –> image
criteria for Canadian Cervical Spine Rule
1) ≥65, dangerous mechanism, or numbness or tingling in extremities
yes –> immobilized and image
2) simple rearend MVC, ambulatory at time of scene, no neck pain at scene, no pain during midline palpation
no –> immobilized and image
3) can actively rotate neck 45 degrees L & R regardless of pain
unable –> immobilized and image
criteria for Ottawa Knee Rule
≥55
tenderness at head of fibula
isolated tenderness of patella
inability to flex to 90
inability to WB immediately 4 steps
criteria for Ottawa Ankle Rule
ankle:
- pain in malleolar zone and
- bone tenderness at posterior edge or
tip of lateral malleolus or medial mal
- or inability to WB
foot:
- pain in midfoot and
- bone tenderness at base of 5th met
or navicular
- or inability to WB
criteria for NOLA & Canadian CT Head Rule
HA
vomiting
>60
drug or alcohol intoxication
deficits in short-term memory (30 mins)
evidence of trauma above clavicle
post-traumatic seizures
failure to reach GSC of 15 w/i 2 hours
