Specific classification of MRI features
| Imaging Feature with: | Classification Criteria |
|---|---|
| Regular enhancing margin | |
| Yes | Smooth enhancing margin on post-Gd T1 |
| No | Lack of smooth enhancing margin on post-Gd T1 |
| Fungating margin | |
| Yes | Thick heterogeneous brushlike enhancing rim on post Gd T1 |
| No | Lack of thick heterogeneous brushlike enhacing rim on post-Gd T1 |
| Cystic | |
| Yes | A well-circumscribed region with low T1 and high T2 signal; loses signal on the FLAIR sequence |
| No | Lack of well-circumscribed region with low T1 and high T2 signal; does not lose signal on the FLAIR sequence |
| Proportion of necrosis | |
| Yes | An area within the tumor that had high signal on T2 and low signal on T1; had heterogeneous enhancement on post-Gd T1; the proportion of the tumor estimated to represent more than 5% necrosis |
| No | Less than 5% or none |
| Proportion of edemaa | |
| Limited (<50% of the entire abnormality) | Less than half of the entire abnormality is estimated to represent vasogenic edema |
| Extensive (> 50% of the entire abnormality) | More than half of the entire abnormality is estimated to represent vasogenic edema |
| Multifocal and multicentric lesion | |
| Yes | Two or more enhancing intra-axial tumors on post-Gd T1 |
| No | One intra-axial tumor on post-Gd T1 |
| Hemorrhage | |
| Yes | Tumor has an area of internal high or isolated T1 and low T2; area of internal high T1 and high T2; area of internal low T1 and low T2. Takes into account that the signal characteristics differ depending on the age of the hemorrhage. SWI sequences were also used. |
| No | No hemorrhage |
Note:—Gd indicates gadolinium.
↵a The protocol for measuring PTE grade was based on that by Wu et al5 and Hartmann et al.22