Extraosseous uptake on bone scintigraphy: Additional information from skeletal examinations

Learning Objectives 1. To provide an overview of bone scintigraphy evaluation of soft tissue abnormalities. 2. To demonstrate specific cases with extra-skeletal accumulation of bone-seeking tracers. 3. To analyze the mechanisms of increased soft-tissue accumulation.

The bone scan remains one of the most frequently performed nuclear medicine studies. It is an important imaging modality to evaluate skeletal disorders. Occasionally, it is also used for the examination of soft-tissue abnormality, such as myositis ossificans, myositis, and so on. Normally, uptake of bone-seeking tracers is seen in the osseous structures and to a lesser degree in the kidneys and bladder. The recognition of specific conditions with extraskeletal accumulation of bone-seeking radiotracers greatly enhances the diagnostic value of the study. However, the extraskeletal uptake of bone-seeking radiotracers is still an unexpected finding in most cases. An additional unusual extra-skeletal uptake in bone scintigraphy is intestinal accumulation. This exhibit will illustrate abnormal patterns of extraosseous uptake on bone scintigraphy of cases collected in our institutions. We will also discuss the etiologies of soft tissue uptake