MR Angiography in the Study of Brain Gliomas

Abstract

Magnetic Resonance and Magnetic Resonance Angiography (MRA) data, obtained from 44 patients with brain gliomas (13 low-grade astrocytoma [LGA], 6 anaplastic astrocytoma [AA], 25 glioblastoma [GBM]), were analysed to evaluate further relevant information linked to tumour malignancy grading and the potential role of MRA in the diagnostic work-up of neuroepithelial brain tumours. MR scanning was performed with a 1.5 superconductive system utilising SE, T1 and SE T2 sequences; signal intensity, perilesional oedema, degenerative changes, tumour borders, enhancement after Gadolinium-DTPA (Gd-DTPA) infusion and the presence of haemorrhagic areas were considered. Feeding vessels, venous drainage, tumour vascularity, displacement or encasement of the main vessels were considered in the analysis of MRA data, performed with the time-of-flight technique (3D and 2D sequences). Oedema, degenerative changes and enhancement after Gd-DTPA were demonstrated only in AA and GBM; the margins of these tumours were irregular and signal intensity was dishomogeneous with haemorrhagic areas in two cases of GBM. In LGA oedema and enhancement were present in four out of 13 cases and degenerative changes only in one. Tumour margins were regular in nine cases and irregular in four; the signal intensity was always homogeneous. Displacement and encasement of the main vessels were better demonstrated with MRA, above all for AA and GBM. Signs of neovascularity were demonstrated only in GBM, in particular the feeding vessels in 14 out of 25 cases, tumour vascularity in six and venous drainage in ten cases.