Combined proton MR spectroscopy and dynamic contrast enhanced MR imaging of human intracranial tumours in vivo

A study was undertaken to determine if the vascular characteristics measure d by dynamic contrast-enhanced magnetic resonance imaging (primarily permea bility surface area product and extracellular-extravascular tissue volume f raction) would be beneficial in explaining the inter-lesion metabolic heter ogeneity displayed by human intracranial tumours. Magnetic resonance spectr oscopy was carried out using a single-voxel STEAM sequence and dynamic imag ing was carried out using a combination of pre-contrast proton density-weig hted FSPGR images (to remove the influence of native tissue T-1), bolus inj ection of Gd-DTPA and subsequent T-1-weighted FSPGR dynamic imaging. A two- compartment pharmacokinetic model was employed to determine vascular charac teristics. Results obtained from 12 meningiomas suggest a possible correlat ion between the level of lipids/macromolecules and permeability surface are a product, although the confounding issue of extra-voxel contamination aris ing from lipids in the scalp and skull marrow cannot be ruled out in the mo re superficial lesions. Results obtained from 11 gliomas (four low and seve n high grade) demonstrate that permeability surface area product is not spe cific for the range of vascular characteristics and metabolite profiles obs erved in gliomas and is therefore unable to explain metabolic heterogeneity in these lesions. Copyright (C0 2000 John Wiley & Sons, Ltd.