Comparison of direct magnification radiography and mammographic film-screen systems in the detection of subperiosteal, intracortical and endosteal bone resorption

Purpose: To compare direct magnification radiography and mammographic film-screen systems in osseous changes of the hand in hyperparathyroidism. Materials and methods: The hands of 60 patients who were suspected to have primary (5), secondary or tertiary (both 55) hyperparathyroidism were evaluated with direct magnification radiography and a mammographic film-screen system (S12.5). Posterior-anterior views of each hand were obtained with both techniques. The magnification radiographs were made with a focal spot size of 40 or 60 mu m, digital luminescence radiography (S600/1200), and a x 6 or 8 magnification. The 240 films were evaluated for subperiosteal, intracortical and endosteal resorptive changes by five radiologists using a grading according to five levels of confidence. Results: A significant improvement (p < 0.05) in the diagnosis of periosteal and intracortical bone resorption was shown, but no significant changes in endosteal resorption with direct magnification radiography. As compared to mammographic film-screen systems, magnification radiography improved the diagnostic accuracy (24%). The time needed for the evaluation of periosteal and intracortical bone resorption was shortened with direct magnification radiography (-4 %/-15 %), and the time for giving the diagnosis decreased (-10 %).