- Discussion:
- for detection of AVN,
technetium-99 methylene-diphosphonate bone-
scanning is a useful technique;
- bone-scanning may be less sensitive in the detection of AVN at early
stage of the disease or when both hips are involved symmetrically;
- reactive of bone at the edge of the infarcted segment will show an increased
uptake of the isotope on the delayed image;
- a photopenic area (cold area) located anterolaterally which is surrounded by
an area of increased activity is most consistent w/ dx of avascular necrosis;
- diff dx:
-
reflex sympathetic dystrophy
-
transient osteoporosis;
- infection;
- tumors;
