title: A computer assisted comparison of 99Tcm-methylene-diphosphonate and 99Tcm-pyrophosphate bone imaging.
abstract: A total of 350 patient studies were carried out using clinical trials' batches of the Technetium (MDP) agent for bone scintigraphy (The Radiochemical Centre), and a commercially available Technetium pyrophosphate agent (CIS). The bone seeking properties of 99Tcm Sn-methylene-diphosphonate (MDP) and 99Tcm Sn-pyrophosphate (PYP) were evaluated by their comparative uptake in compact bone, cancellous bone and soft tissue using a region-of-interest technique. From these data uptake ratios were computed in order to correlate the values with (a) the amount of 99Tcm-MDP injected, (b) the time after injection and (c) the age of patients examined. All ratios derived with 99Tcm-MDP were superior to those using 99Tcm-PYP and were not dependent on the amount of 99Tcm-MDP injected. Uptake ratios determined for 99Tcm-MDP (1.5 h to 2.5 h after injection) were found to be higher than those for 99Tcm-PYP 2.5 to 3.5 h after injection. Soft tissue accumulation of 99Tcm-MDP, visible on scintiphotos, occurred only in 26% of cases but with 99Tcm-PYP, in 75% out of all cases studied. A decrease of cancellous bone/compact bone ratios with increasing age of the patients was found with both radiopharmaceuticals. This is most probably correlated with a diminished mass and/or surface of the cancellous bone in the elderly patient.
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D003201:Computers; D011756:Diphosphates; D004164:Diphosphonates; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011877:Radionuclide Imaging; D013667:Technetium
chemical_list: D011756:Diphosphates; D004164:Diphosphonates; D013667:Technetium