Table 2.

Categories used to classify structural MRI findings.

Category	Radiological findings on MRI
C1	No abnormality.
C2	Minimal abnormality, such as subependymal hemorrhage or mineralization (e.g. sequelae of germinal matrix hemorrhage) with or without mild ventriculomegaly, with or without mild IVH.
C3	Moderate to severe ventriculomegaly, with or without IVH
C4	Parenchymal abnormality, including evidence of gray and/or white matter injury due to hemorrhage or ischemia, with or without IVH.
C5	Congenital malformation (excluded from further analyses)