B6.070 Large Group MSK Imaging Flashcards
describe key features of the iliac bone
iliac crest - abdominal muscle attachments
anterior superior iliac spine - origin of sartorius and tensor fascia lata
anterior inferior iliac spine - origin of straight head of rectus femoris
sacral foramen
sacral nerve foots travel through here
ischial tuberosity
origin of hamstring tendons
pubic bone
origin of adductors
what is the significance of the pelvis being 3 rings
hard to break a ring in only one place…look around for multiple fractures
ileopectineal line
traces lower quadrant of the major pelvic circle
obturator ring
traces small rings below the main ring of the pelvis
Shenton’s arc
continuous line from lower line of the femoral neck through the top of the obturator ring on the same size (should line up)
3 main types of fractures at femoral head/neck
subcapital
transcervical (neck)
intertrochanteric
avascular necrosis of the femoral head
blood supply to femoral head runs through femoral neck
risk of avascular necrosis of femoral head increases with degree of displacement of fracture
initial study for suspected hip fracture
pelvic radiographs
choice of study for suspected, radiographically occult hip fracture
pelvic MRI
why would you image a diabetic foot wound?
to determine the presence of osteomyelitis
initial study for diabetic foot wound
xray and MRI both 9 on ACR criteria
key finding in xray of diabetic foot
atherosclerotic calcification of small vessel of the foot
T1 coloration
fat and contrast appear bright
T2 coloration
water is bright
edema = increased water content
how to determine hyperemia on T1 sequence
fat suppressed view
can see where contrast accumulates in pt
annual rate of foot ulcers in diabetics
2-5%
what % of non traumatic LE amputations are in diabetics
40-60%
what % of diabetic amputations are preceded by foot ulcers
85%
etiology of diabetic foot wounds
neuropathy: altered weight bearing in foot and development of pressure ulcers, increased risk of trauma due to loss of protective sensation
vasculopathy: decreased blood flow to affected tissue and decreased delivery of leukocytes and Abx
increased serum blood glucose: impaired action of neutrophils
ttx of diabetic foot wounds
oral Abx and limited debridement for limited cellulitis
extended IV antibiotics and amputations in advanced disease
key bone findings of diabetic foot wounds on xray
irregularity of cortical bone and periostitis
gross destruction of the cortical and underlying trabecular bone
MRI findings of osteomyelitis
LOW T1 and HIGH T2 intensity
increased bony enhancement on post contrast T1 image
