Accumulation of sup(99m)Tc-methylene diphosphonate in a So-called conversion defect of the femoral neck

99m-Tc-methylene diphosphonate (sup(99m)Tc-MDP) was found to accumulate in one of the two radiolucent areas of the bilateral femoral neck, both of which were radiographically typical of the so-called conversion defects of the proximal femur, a type of normal roentgen variant. The mechanisms possibly involved in this previously unreported phenomenon are discussed in relation to the apparent discrepancy regarding radionuclide uptake by the two lesions of the same entity in one patient. (orig.)