Diagnosis of osteoid osteoma using computed tomography.

Osteoid osteoma is a benign lesion of bone generally diagnosed using conventional radiography or conventional tomography. Computed tomography can be used in difficult cases to localize a clinically suspected lesion. In this report we present two patients in whom an osteoid osteoma was detected using computed tomographic scanning; in an additional patient computed tomography failed to localize a lesion, probably because the slice thickness was too great. Because the nidus of the lesion is small--generally several millimeters in diameter--accurate CT localization requires that narrowly collimated, closely spaced sections be obtained.