Scintigraphy of meningiomas: radiologic--pathologic correlations in 32 cases.

Abstract

Abstract Ninety per cent of meningiomas were detectible by radioisotopic imaging in both the authors' series of 32 patients and in a review of the literature, a slightly lower accuracy than by cerebral angiography. These tumors were best demonstrated in images taken 1–2 min after the intravenous injection of 99m Tc pertechnetate. The tumor concentration tended to fade after one to several hours, unlike the majority of intracerebral tumors which often show an increasing concentration with time. Eighty-one per cent of these meningiomas showed increased perfusion in first transit rapid sequential images, usually appearing about 15 sec after injection. This abnormal perfusion tends to be more marked, appears later and persists longer than in most intracerebral neoplasms. The perfusion study does not improve the tumor detection rate but helps to identify them as meningiomas. A reasonable correlation was found between the degree of increased tumor perfusion and the intensity of the angiographic tumor stain. Both, however, failed to correlate to the degree of tumor vascularity evaluated histologically. No distinguishing features were found in the radioisotopic studies or angiographically between the four major histological types of meningioma, except that the angioblastic type invariably showed marked vascularity.