ISSUES WITH BONE SCANS Flashcards
complicating factors?
active sterile bone inflammation
- fracture
- diabetic foot
- neoplasms
septic arthritis
false negatives w/ certain antibiotics
reliability issues?
they remain hot for 9-12 months after major bone trauma (fracture, OM, implant)
- fracture
- OM
- Implant
so when the normal (negative) bone rules out the probability of OM in diabetics w/ infected foot ulcers what does this mean?
false + in up to?
false - in up to?
based on these percents, bone scanning is not
25%
17%
this type of scanning? takes a different radionuclide agent? and combines it with TC…
sequential scanning
gallium (67Ga)
major characteristics of gallium (67Ga)?
inflammatory scan, goes to area of inflammation with no affinity
not seen around appendicular skeleton
T/F, peaks do not interfere w/ TC at 140?
T
how does the sequential scanning work?
TC first then scan GA around 18-72 hrs
what is the 67GA half life?
78 hrs, so not given to peds
what is the mechanism of uptake for 67Ga?
high affinity for iron
direct uptake by bacteria and leukocytes
increased vessel permeability
special incongruity of Ga with bone indicates what type of infection?
positive for infection
spatial incongruity of Ga with bone indicates what type of infection?
negative for infection
what is the type of study when we see uptake around the R/L femoral + tibial components and is congruent in terms of spatial uptake and intensity?
equivocal study
why has Ga been abandoned?
high amounts of false negatives
significance of Ga?
more accurate for monitoring OM therapy
major indication is for axial skeleton where the indium studies are inaccurate
significant of 111In?
gets added to WBCs and wherever they go the 111In goes
