- Bone scan:
- generally considered sensitive but not specific;
- bone scans may help to r/o associated conditions such as a
stress frx;
-
Triphasic Bone Scan:
- may add higher degree of specificity;
- first stage is the radionucleotide arteriogram:
- increased uptake is suggestive of RSD;
- second stage is the blood pool stage:
- this is suggestive of RSD if there is diffuse increase in activity in the MCP and juxta articular regions of the digits;
- third stage is the delayed stage (typically 3-4 hours)
- is suggestive if there is diffuse assymetric uptake in radiocarpal, intercarpal, MCP and IP joint in the affected limb;
- third phase is the most important phase;
