FIG 1. MR imaging study of a 37-year-old patient with a grade 3 oligodendroglioma before treatment.

A, Axial T2-weighted image (6000/105.5/2 [TR/TE/NEX]) at the level of the lateral ventricles shows a large heterogeneous tumor mass centered on the insular region and containing a complex cyst.

B and C, rCBV maps of a perfusion-weighted MR image obtained by using a dynamic susceptibility-weighted single shot echo planar sequence (1200/40/1) and 1 mmol/kg meglumine gadoterate bolus injected at a rate of 5 ml/s. B, Areas of increased rCBV (shown in red) are seen in the insular tumor portion. Measurements of the rCBV in that area ranged from 4.74 to 6.82 (mean, 5.49), by using the contralateral white matter as reference. C, There is no increased of rCBV in the temporal tumor portion, situated posterior to the right middle cerebral artery, which is a structure of a high blood volume and therefore shows up as red. The mean rCBV of the temporal tumor was 1.04.

D and E, ADC maps of a diffusion-weighted image (10,000/93.3 [TR/TE]; b = 1,000 s/mm²). D, Axial section at the level of the lateral ventricles shows that the tumor surrounding the complex cyst in right insular region appears hypointense relative to normal white matter. Regions of interest placed in this area had ADC measurements from 0.70 to 0.89 x 10^–3 mm²/s (mean, 0.76) E, Axial section through the temporal lobes shows that the tumor in the right temporal lobe appears hyperintense relative to normal white matter, with ADC measurements ranging from 1.39 to 1.49 x 10^–3 mm²/s (mean 1.44).