091014 musculoskeletal imaging Flashcards
how do you decide on appropriate imaging modality?
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!
what should you look for on imaging
hardware, joints, bones, soft tissues
for fractures, hardware failure, calcifications, tumors, degnerative arthritis
what should you look on the apex of the lung for
tumors (Pancoast tumor)
displaced fracture
ends are no longer attached
clay shoveling fractures
vertebral spinous process fractured
imaging projections
one view is no view
projections is a term used for radiographs
imaging planes
term used for CT, MRI
if fall on elbow, common fracture site?
radial head
and may cause fat pads to be pushed up
fractures show up
sometimes immediately, sometimes not
which kind of fractures have the worse sequelae
transverse
twisted knee-what should you think of?
ligamentous injuries
CT in knee is good for
if you know that there is a fracture and to confirm it; to see how many pieces in it
MRI is good for
ligaments, musculoskeletal
sesamoid bones
bone embedded within tendon where the tendon passes over a joint
imaging differential diagnosis-what to think about
vascular infection neoplasm drugs inflammatory or idopathic congenital autoimmune trauma endocrine or metabolilc
pathologic fracture
an insufficiency fracture
normal stress on an abnormal bone
stress fracture
abnormal stress on a normal bone
malignant lesion in bone
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
calcific tendonitis
benign
causes lot of pain
doeesn’t need srugery (treat with meds or aspirate)
where can you see effusions most easily
knee, then elbow, ankle, wrist, fingers
hip (is ok in a child but difficult to see an effusion in adults)
how can seeing effusions help?
they are non-specific but
can be due to degen arthritis, infection, inflam arthritis, gout, etc
what do lipohemarthoris indicate
fracture (fat came from medullary canal-the marrow is fatty.
apposition
describes how the ends of fragments come into contact w/ one another
angulation
describes the loss of the bone alignment
comminution
bone is crushed or splintered into two or more pieces
jones fracture
fifth metatarsal base-transverse fracture at proximal base; no displacement, no angulation, not intraarticular
avulsion fracture
where a tendon or ligament pulls a piece of bone off
