Radionuclide imaging in the diagnosis of osteoid osteoma.

Oseteoid osteoma is a well-known type of benign bone-forming tumor, which has previously been diagnosed using plain radiograph imaging. However, diagnosis of osteoid osteoma may be delayed due to ambiguities on plain radiograph images; despite the increasing use of magnetic resonance imaging (MRI), this type of misdiagnosis is not uncommon. The aim of the present study was to evaluate the effectiveness of radionuclide imaging scans for the diagnosis of osteoid osteoma, as this form of imaging was proposed to be a more sensitive test. The characteristics of 18 cases of osteoid osteoma were analyzed based on diagnostic imaging and the time from initial recognition of symptoms by the patient to diagnosis. Diagnostic modalities included plain radiograph, computed tomography (CT), MRI and radionuclide imaging. Among the 18 patients, 14 patients had unique positive findings in plain radiographs. The mean duration between initial cognition of symptoms to the diagnosis for these patients was 5.2 months (range, 3.8-9.3 months). A total of 4 patients exhibited no radiographic abnormalities in the initial plain radiographs and were diagnosed a mean of 18.5 months (range, 17-20 months) following the onset of symptoms. Overall, radionuclide imaging was performed on 16 patients and all of the cases demonstrated positive findings. In these cases, 28.6% of osteoid osteoma patients with clinical indications revealed no abnormal findings in plain radiographs. Therefore, in situations such as these, radionuclide imaging may be a useful indicator for diagnosis, as these results have demonstrated that it positively identified all cases of osteoid osteoma. In addition, the results of the present study indicated that if the radionuclide imaging was positive, CT scan was a more valuable diagnostic tool, whereas if the radionuclide imaging was negative, MRI should be recommended for the diagnosis of other undiscovered disease entities.