Use of dynamic susceptibility-contrast MRI (DSC-MRI) to assess perfusion changes in the ipsilateral brain parenchyma from glioblastoma

Abstract

We investigated the effect of increased tumor perfusion using dynamic susceptibility-contrast magnetic resonance imaging (DSC-MRI) in glioblastoma (GBM) patients on the surrounding ipsilateral brain tissue with respect to perfusion of the normal, unaffected contralateral brain and of the tumor. DSC-MRI was performed in 11 patients with glioblastoma using a multislice T2*-weighed EPI sequence (TR/TE = 2,000/62 ms; FOV 240 mm; matrix 128 x 128; slice thickness 6 mm) on a standard clinical 1.5 Tesla scanner during intravenous injection of 40 cc Gadolinium-DTPA at a flow rate of 5 cc/s. Maps for relative regional cerebral blood volume (rCBV) and relative regional cerebral blood flow (rCBF) were created and relative values analyzed in relation to the arterial input. Relative CBV and CBF were significantly higher in gray matter than in the respective white matter (paired t-test; P < 0.001) with a high correlation for both perfusion parameters between the gray and the white matter in both ipsilateral and contralateral brain (P < 0.001). The highest values for rCBV and rCBF were found in solid tumor tissue with a significant positive correlation between tumor and the adjacent gray matter (for both rCBV and rCBF; P < 0.001). In GBM patients there is increased metabolism and thus increased rCBV and rCBF within the tumor. This increased perfusion of the tumor is not at the expense of perfusion of the ipsilateral normal brain parenchyma and in fact, the rCBV and rCBF values are linked to tumor-induced changes in rCBV and rCBF.