Table 4.

Proposal of a structured CUS assessment of white matter injury.

Mild	Bilateral hyperechoic change in white matter near the superolateral angle of the lateral ventricles on coronal images (flaring); most pronounced in posterior frontal to occipital areas; gradually disappearing over days
Moderate	a. Hyperechoic change persisting beyond the first week with heterogeneous appearance (patchy); hyperechoic “gliotic” nodules under the pre- and/or post-central gyrus (=pathological flaring)	Atypical variants Clusters of multiple hyperechoic dots in corona radiata in ELBW infants
	b. Homogeneous hyperechoic change followed by one or two of signs of white matter loss	Atypical variants Homogeneous hyperechoic change without cavitation but with secondary hyperechoic change in pulvinar
	c. Localized cyst formation adjacent to the external angle of the lateral ventricle in the subrolandic area	Atypical variants Isolated bilateral anterior frontal cystic periventricular leukomalacia Isolated bilateral postrolandic cystic periventricular leukomalacia
Severe	a. Hyperechoic change persisting beyond the first week with heterogeneous appearance (patchy) associated with more than two signs of white matter loss in serial scans
	b. Extensive cysts in fronto-parietal and occipital periventricular white matter (cystic periventricular leukomalacia)
White matter volume assessment at term equivalent age
	Coronal measurements indicating frontal white matter loss	Levene ventricular index at the foramen of Monro: >13 mm Roof to floor distance of the frontal horn at the foramen of Monro: >3 mm
	Parasagittal measurements indicating peritrigonal and occipital white matter loss	Midbody >10 mm roof to floor distance thalamo-occipital distance >24 mm
	Measurement of enlarged subarachnoid spaces	Coronal width of the interhemispheric fissure, measured at the foramen of Monro: distance between hemispheres >3 mm Sino-cortical width in coronal view at the foramen of Monro >4 mm
	Measurement of thinning of corpus callosum	Thickness of the body of corpus callosum in midsagittal view <1.5 mm