Central nervous system disorders

VII./3.4.: Perfusion studies

Both CT and MRI can detect the passage of the contrast bolus in the tumor. Very quick measuring times are required on the course of both CT and MRI examinations in order to be able to detect the transit time of contrast bolus at certain times. Vascularisation and environmental effects of meningeoma can be concluded from these values (echo-planar contrast enhanced T2* weighted MR sequence is used). On CT increasing density, on MR signal loss can be observed according to the appropriate timing of contrast passage.

Obtained diagrams are characteristic of permeability – distribution between intravascular and extravascular compartments (neither CT nor used MRI contrast agent has intracellular distribution). Comparison of intratumoral regional cerebral blood flow (rCBV) with that of the contralateral white matter provides the perfusion diagrams. Obtained results can be demonstrated well using both methods (CT/MRI) if colors are rendered to the values of blood content (color mapping). These perfusion diagrams are also useful in the differential diagnostics of benignity vs. malignancy (see above the external carotid artery versus pial and cortical blood supply).