Functional bone imaging in the detection of ischemic osteopathies.

The efficiency and accuracy of a functional imaging technique in the detection of ischemic osteopathy is reviewed over a 10-year period. The study includes 161 patients who had trauma, 101 patients who had suspected Perthes disease, 43 patients who had dysbarism, and 22 patients who had renal transplants on steroid immunosuppressive therapy. After intravenous injection of 7.7 MBq kg-1 Tc-99m HDP data were collected on all patients during the first 20 minutes, accretion rate functional images were produced, and static bone scans performed after 3 hours. All patients were followed up until a definitive diagnosis (clinical and radiologic) of avascular necrosis or osteochondritis was confirmed or denied. Of the 327 patients studied, 114 had positive accretion rate images and 213 negative accretion rate images. There were 8 false-positive scan results and 2 false-negative scan results. The overall predictive accuracy was 97% (disease prevalence 33%) with a sensitivity rate of 98% and a specificity rate of 96%. The authors conclude that the technique is a valuable predictive diagnostic indicator for ischemic osteopathies.