Grading of white matter abnormalities based on ultrasonography and MR imaging
| Description of White Matter Abnormalities | |
|---|---|
| Ultrasonography | |
| Grade 1 | Small foci of abnormal echogenicity less echogenic than choroid plexus |
| Grade 2 | Diffuse foci of increased echogenicity less than the choroid plexus or irregularity of the lateral borders of the periventricular white matter (junction of the normal halo and surrounding cortex) |
| Grade 3 | Focal areas of abnormal echogenicity greater than or equal to the echogenicity of the choroid plexus |
| Grade 4 | Diffuse increased echogenicity greater than or equal to the echogenicity of the choroid plexus |
| Grade 5 | Periventricular cysts (cavitation) defined as anechoic regions with increased through transmission |
| MR imaging | |
| Normal | No periventricular white matter abnormalities |
| Minimal white matter abnormality | Three or fewer areas of T1 signal abnormalities measuring <2 mm |
| Moderate white matter abnormality | Three areas of T1 signal abnormalities or areas measuring >2 mm but <5% of the hemisphere involved* |
| Severe white matter abnormality | T1 signal abnormalities involving >5% of the hemisphere |
* Percent of hemisphere involved estimated by visual inspection.