99mTc-MDP uptake and histological changes during rat bone marrow regeneration.

An established experimental model of tibial bone regeneration in rats was used in order to try to provide further information on the binding site of 99mTc-MDP, which is still not clearly defined. Four groups of rats on which surgical tibial bone marrow evacuation was performed and two control groups (nonoperated animals and sham-operated animals) underwent bone scan during the different stages of marrow regeneration; they were killed immediately after, and histological examination carried out. The correlation between the scintigraphic and the histological findings suggests that 99mTc-MDP binds primarily to calcification sites in young bone trabecules.