Efficacy of skull imaging in routine bone scanning

The frequency of abnormal skull images in patients undergoing ⁹⁹Tc(m) Sn diphosphonate bone imaging is reviewed. In 181 patients with known malignant tumors, 47% had abnormal scans of the axial skeleton and 28% had abnormal skull images. Only 2 of these 181 patients had abnormal skull images and a normal scan of the axial skeleton. In 38 patients with benign disorders the skull image was abnormal in 6, all with Paget's disease. No patient with a benign disorder had skull involvement alone.