Scintigraphy with Technetium-99m methylene diphosphonate (MDP) delineates a wide spectrum of nonosseous disorders. 99mTechnetium-methylene diphosphonate (MDP) bone isotope may accumulate in many extraosseous sites due to variety of both benign and malignant conditions. Neoplastic, hormonal, inflammatory, ischemic, traumatic, excretory, and artifactual entities demonstrate abnormal soft-tissue uptake of Tc-99m MDP. Mechanisms leading to increased extraosseous Tc-99m MDP uptake includes extracellular fluid expansion, enhanced regional vascularity and permeability, and elevated tissue calcium concentration. Usually metastases in the liver shows focal rather than diffuse uptake of Tc-99m MDP. Recognition of these modes of extraskeletal Tc-99m MDP uptake can enhance the diagnostic value of bone scintigraphy.
Tc-99m MDP Bone Scintigraphy, Liver Uptake, Renal Cell Carcinoma Metastases
