091014 musculoskeletal imaging

Question 1

how do you decide on appropriate imaging modality?

Answer 1

what is the clinical question? what tests answer it?
consider body part of interest
differential diagnosis
age of pt (90 yo-may be more liberal)
pt history (if pregnant)
cost of exam
radiation dose 
availability

answer may be NO test, if it’s obvious on clinical!

Question 2

what should you look for on imaging

Answer 2

hardware, joints, bones, soft tissues

for fractures, hardware failure, calcifications, tumors, degnerative arthritis

Question 3

what should you look on the apex of the lung for

Answer 3

tumors (Pancoast tumor)

Question 4

displaced fracture

Answer 4

ends are no longer attached

Question 5

clay shoveling fractures

Answer 5

vertebral spinous process fractured

Question 6

imaging projections

Answer 6

one view is no view

projections is a term used for radiographs

Question 7

imaging planes

Answer 7

term used for CT, MRI

Question 8

if fall on elbow, common fracture site?

Answer 8

radial head

and may cause fat pads to be pushed up

Question 9

fractures show up

Answer 9

sometimes immediately, sometimes not

Question 10

which kind of fractures have the worse sequelae

Answer 10

transverse

Question 11

twisted knee-what should you think of?

Answer 11

ligamentous injuries

Question 12

CT in knee is good for

Answer 12

if you know that there is a fracture and to confirm it; to see how many pieces in it

Question 13

MRI is good for

Answer 13

ligaments, musculoskeletal

Question 14

sesamoid bones

Answer 14

bone embedded within tendon where the tendon passes over a joint

Question 15

imaging differential diagnosis-what to think about

Answer 15

vascular
infection
neoplasm
drugs
inflammatory or idopathic
congenital
autoimmune
trauma
endocrine or metabolilc

Question 16

pathologic fracture

Answer 16

an insufficiency fracture

normal stress on an abnormal bone

Question 17

stress fracture

Answer 17

abnormal stress on a normal bone

Question 18

malignant lesion in bone

Answer 18

very irregular (not sure where it begins and where it ends)

going out into soft tissues-fluffy white tissue-periosteal rxn

Codman’s triangle-periosteum trying to contain the lesion

no sclerotic margin

Question 19

calcific tendonitis

Answer 19

benign
causes lot of pain
doeesn’t need srugery (treat with meds or aspirate)

Question 20

where can you see effusions most easily

Answer 20

knee, then elbow, ankle, wrist, fingers

hip (is ok in a child but difficult to see an effusion in adults)

Question 21

how can seeing effusions help?

Answer 21

they are non-specific but

can be due to degen arthritis, infection, inflam arthritis, gout, etc

Question 22

what do lipohemarthoris indicate

Answer 22

fracture (fat came from medullary canal-the marrow is fatty.

Question 23

apposition

Answer 23

describes how the ends of fragments come into contact w/ one another

Question 24

angulation

Answer 24

describes the loss of the bone alignment

Question 25

comminution

Answer 25

bone is crushed or splintered into two or more pieces

Question 26

jones fracture

Answer 26

fifth metatarsal base-transverse fracture at proximal base; no displacement, no angulation, not intraarticular

Question 27

avulsion fracture

Answer 27

where a tendon or ligament pulls a piece of bone off