The abnormal bone scan in intracranial lesions.

In 43 patients with abnormal brain scans restudied within 2-7 days with 99mTc-labeled ethane-1, hydroxy-1, diphosphonate (EHDP), cerebral infarctions, primary and metastatic neoplasms, chronic subdural hematoma, arteriovenous malformations and inflammatory lesions were visualized. The localization of EHDP in primary and metastatic neoplasms is usually less apparent than pertechnetate. Conversely, the localization of EHDP in cerebral infarctions is usually more apparent than pertechnetate. 99mTc-EHDP, in conjunction with pertechnetate, may become useful in differentiating cerebral infarctions from neoplasms. Further, skull scans must be interpreted with the appreciation that bone-seeking radiopharmaceuticals may localize in a variety of intracranial lesions.