SPECT-CT for characterization of extraosseous uptake of 99mTc-methylene diphosphonate on bone scintigraphy.

Bone scintigraphy is a sensitive and popular method for imaging a wide array of benign or malignant skeletal abnormalities. However, the uptake of tracers used for bone scintigraphy may be observed in various extraosseous sites, thereby limiting its specificity. It is difficult to correctly localize such sites of uptake on planar bone scintigraphy alone. The addition of hybrid single-photon emission computed tomography-computed tomography (SPECT-CT) under such circumstances is very useful. The present essay illustrates the commonly encountered extraosseous uptake of 99mTc-methylene diphosphonate (MDP) and the usefulness of hybrid SPECT-CT in clarifying 99mTc-MDP uptake.