Abnormal radionuclide deposition patterns adjacent to focal skeletal lesions.

A scintigraphic pattern is described for bone scans with 99m-Tc-polyphosphate and 99m-Tc-diphosphonate in which abnormal tracer accumulation extends beyond the known limits of certain skeletal lesions. The associated pathologic entities include benign and malignant tumors, infection, and trauma. The pathogenesis of "extended patterns" has not been proved but probably relates to regional hyperemia induced by associated lesions. Increased blood flow results in more tracer delivery to otherwise normal bone in the "watershed" areas of hyperemia, producing these patterns.