Background US is a safe and useful tool to evaluate neonatal brain. Its accuracy in revealing abnormalities and predicting prognosis is still to be completely defined. Aim of this study is to assess the diagnostic value and the prognostic accuracy of US in newborns with HIE.
Methods During a 17 months period, newborns with HIE were prospectively recruited. US was performed by a microconvex probe 6.5–7.5 MHz (Esaote AU4) within 24–72 hours of life and at 5–7 days of life. The following pathological patterns were defined: diffuse hyperechogenicity, split-like ventricles; basal ganglia hyperechogenicity, parasagittal hyperechogenicity. Outcome at 24 months of life is reported (Griffiths test).
Results 30 term newborns were recruited (Sarnat I, II, III: 16, 13 and 1, respectively); US was normal in 21 newborns and pathological in 9 patients (interobserver agreement 0.6). 21 patients developed normal outcome, 4 transient hypertonia, 4 cerebral palsy, 1 was lost at follow-up. US sensitivity and specificity in predicting motor outcome were 100% and 84%, respectively (PPV and NPV: 50% and 100%, respectively). Among pathological lesions those associated with normal motor outcome were lesions at parasagittal level. Mean (SD) GQ was 103 (9) and 80 (33) in patients with normal and pathological US, respectively (p<0.05).
Discussion US showed good sensitivity in detecting lesions associated with increased risk of adverse outcome. However, 50% of patients with pathological US showed a normal outcome, especially those with parasagittal hyperechogenicity. US performed in real-time, by expert neonatologists, using state-of-the-art US equipments may show better accuracy than reported in the past.