Brain MRI is helpful in the diagnosis of glioblastoma multiforme. On brain MRI, glioblastoma multiforme is characterized by a butterfly shaped mass, which is hypointense on T1-weighted MRI and hyperintense on T2-weighted MRI.
MRI
Brain MRI is helpful in the diagnosis of glioblastoma multiforme. On brain MRI, glioblastoma multiforme is characterized by:
Susceptibility artifact on T2 from blood products (or occasionally calcification)
Low intensity rim from blood product
Located inside the peripheral enhancing component
Absent dual rim sign
DWI/ADC
Solid component
Elevated signal on DWI is common in solid / enhancing component
Diffusion restriction is typically intermediate similar to normal white matter, but significantly elevated compared to surrounding vasogenic edema (which has facilitated diffusion)
ADC values correlate with grade:
WHO IV (GBM) = 745 ± 135 x 10-6 mm2/s
WHO III (anaplastic) = 1067 ± 276 x 10-6 mm2/s
WHO II (low grade) = 1273 ± 293 x 10-6 mm2/s
ADC threshold value of 1185 x 10-6 mm2/s sensitivity (97.6%) and specificity (53.1%) in the discrimination of high-grade (WHO grade III & IV) and low-grade (WHO grade II) gliomas
Non-enhancing necrotic / cystic component
Majority (>90%) have facilitated diffusion (ADC values > 1000 x 10-6 mm2/s)
MR perfusion
rCBV elevated compared to lower grade tumors and normal brain
