Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
MRI
Brain MRI is helpful in the diagnosis of glioblastoma. On brain MRI, glioblastoma is characterized by:[1]
|
MRI component
|
Features
|
- T1
|
|
- T1 C+ (Gd)
|
- Enhancement is variable
- Typically peripheral and irregular with nodular components
- Usually completely surrounds necrosis
|
- T2/FLAIR
|
- Hyperintense
- Surrounded by vasogenic edema
- Flow voids
|
- GE/SWI
|
- 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
|
- MR spectroscopy
|
- Choline: increased
- Lactate: increased
- Lipids: increased
- NAA: decreased
- Myo-inositol: decreased
|
-
Image 1b. Sagittal MRI with contrast of a glioblastoma WHO grade IV in a 15-year-old boy
-
Image 1a. Coronal MRI with contrast of a glioblastoma WHO grade IV in a 15-year-old boy
Patient #1: Presented with increasing headaches
Patient #2
References
Template:WikiDoc Sources