title: Increased activity on immediate phase of bone imaging does not always indicate increased blood volume.
abstract: The immediate Tc-99m MDP image of a neoplastic right wrist mass in a 10-year-old boy demonstrated intense focal accumulation that suggested a very vascular tumor, but delayed images showed only slightly increased activity in the mass. A Tc-99m labeled RBC study was performed to permit whole-body blood pool imaging for other vascular lesions, and it did not demonstrate an increased blood volume in the mass. Biopsy showed the tumor to be a Ewing's sarcoma, probably of soft tissue origin. The sarcoma was not very vascular. The intense immediate accumulation of Tc-99m MDP in this case may be attributed to increased microvascular permeability.
mesh_terms: D001706:Biopsy; D001810:Blood Volume; D001859:Bone Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D002199:Capillary Permeability; D002648:Child; D003937:Diagnosis, Differential; D004912:Erythrocytes; D006801:Humans; D008297:Male; D008833:Microcirculation; D011877:Radionuclide Imaging; D012512:Sarcoma, Ewing / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D013669:Technetium Tc 99m Medronate; D014457:Ulna / Q000473:pathology
chemical_list: D013669:Technetium Tc 99m Medronate