Prolonged injection angiography for diagnosing intracranial neoplasms.

Prolonged injection angiography (PIA), in which large amounts of contrast material are administered for three or four seconds, was used to visualize the vasculature of 70 intracranial neoplasms. Tumor stains were demonstrated better with or solely by PIA in all pituitary adenomas with suprasellar extension and in most meningiomas. PIA was less effective in tumors with marked arteriovenous shunts or in low-grade gliomas. PIA is especially indicated when avascular or hypovascular masses are encountered on conventional angiography or when contrast enhancement is encountered on computed tomography (CT). PIA is also indicated to demonstrate neoplasms which are not enhanced with contrast media on CT since PIA demonstrates the venous anatomy surrounding the tumors especially well.