Kim Annink

58 Chapter 3 Table 1: Continued Patient characteristics Hypothermia (n=20) No hypo- thermia (n=13) p-value hypothermia vs. no hypothermia Controls (n=22) p-value HIE vs. controls Predominant type of supra- tentorial brain injury, n (%) Watershed Basal ganglia thalami Near total injury 3 (15.0%) 12 (60.0%) 5 (25.0%) 2 (15.4%) 8 (61.5%) 3 (23.1%) 0.99 n/a n/a n/a n/a Field strength MRI, n (%) 1.5 Tesla 3.0 Tesla 0 (0.0%) 20 (100.0%) 11 (84.6%) 2 (15.4%) <0.001 0 (0.0%) 22 (100.0%) 0.002 Postnatal age at MRI in days, median (IQR) 4.0 (3.0 - 4.8) 2.0 (1.0 - 4.5) 0.02 7.5 (5.0 – 9.0) p<0.001 Postnatal age at death in days, median (IQR) 4.5 (3.0 – 5.0) 4.0 (2.0 – 6.0) 0.95 n/a n/a Days between MRI and death, median (IQR) 0.0 (0.0 – 1.0) 1.0 (0.5 – 1.0) 0.05 n/a n/a Interrater variability ADC measurements The correlation of ADC values between the two different observers was good for the cerebellar hemispheres (r=0.87, p<0.001), the vermis (r=0.80, p<0.001) and the DN (r=0.93, p<0.001). ADC values Mean ADC values in the DN (HIE: 1004 ± 152x10 -6 mm 2 /s; controls: 1140 ± 82x10 -6 mm 2 /s; p<0.001) and cerebellar vermis (HIE: 785 ± 113x10 -6 mm 2 /s; controls: 859 ± 72x10 -6 mm 2 /s; p=0.009) were significantly lower in neonates with HIE compared to controls, but there was no significant difference in ADC values in the cerebellar hemispheres (HIE: 1072 ± 121x10 -6 mm 2 /s; controls: 1115 ± 89x10 -6 mm 2 /s; p=0.162) (Figure 3A,B). ADC values in the infants with HIE were not correlated with postnatal age at MRI.