Kim Annink

76 Chapter 4 Table 1: Continued Normal-mildly abnormal (0) Moderately abnormal (1) Severely abnormal (2) Total points Hyperechogenicity subcortical white matter Normal echogenicity or minor hyperechogenicity. Focal hyperechogenicity of the subcortical white matter. Moderate differentiation of white and (subcortical) grey matter. Clear “tramlines” sign; hyperechogenicity of subcortical white matter almost similar to sulci with hyposignal intensity of cortex in between. Hyperechogenicity thalamus Normal echogenicity or minor hyperechogenicity. Moderate or focal hyperechogenicity thalamus. The hyperechogenicity is severe and diffuse. Hyperechogenicity putamen Normal echogenicity or minor hyperechogenicity. Moderate or focal hyperechogenicity putamen The hyperechogenicity is severe and diffuse. Absent (0) Present (1) Total points Four column sign Normal echogenicity to minor hyperechogenicity On the coronal CUS plane there is a four column sign caused by moderate or severe bilateral hyperechogenicity of the thalamus and putamen. Visibility PLIC The PLIC is not visible as a hypo-echogenic line between the putamen and thalamus. The PLIC is clearly visible as a hypo-echogenic line between the hyperechogenic putamen and thalamus. After the development of the scoring system, a neonatologist, with more than ten years of experience in neonatal neurology and CUS, scored all CUS in cohort I (observer 1). First, the association between all separate items and adverse outcome was determined. Because of multicollinearity all white matter items were summed into a white matter score, the deep grey matter items into a grey matter score and the resistance index remained a separate item. Next, the association between the different composite scores in the scoring system and adverse outcome was calculated.