Detection of cranial metastases by F-18 FDG positron emission tomography.

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scanning has been useful in the management of various cancers. The normal glucose use of gray matter often limits the detection of metastatic lesions to the brain and skull with FDG PET. The authors report two cases of calvarial metastases: one with pheochromocytoma and the other with non-small-cell lung carcinoma. These cases illustrate the crucial role that FDG PET can play when patients are examined for metastases. The important concept of contrast resolution that is achieved with PET imaging is discussed as an advantage that significantly overcomes its limited spatial resolution in detecting small lesions that may not be detected by anatomic imaging techniques with high spatial resolution.