Authors
Olivia Carney, Emer Hughes, Nora Tusor, Ralica Dimitrova, Lucilio Cordero-Grande, Andrew Chew, Shona Falconer, Joanna Allsop, Jo Hajnal, Daniel Rueckert, Steve Smith, A David Edwards, Mary Rutherford.

Institution(s)
Centre for the Developing Brain,
Department of Perinatal Imaging,
St Thomas’ Hospital, London

Introduction
Interpretation of incidental image findings on MRI imaging of the Term neonatal brain can be challenging as there is a lack of published normative data on low risk term neonates. The purpose of this study was to determine the prevalence of incidental findings in a large group of normal term infants participating in the Developing Human Connectome project (dHCP) with normal neurodevelopmental outcomes at 18 months.

Methods
We conducted a retrospective review of the MRI brain image findings in a large cohort of term neonates (n=500; 279M:221F; GA 37+1 – 42+2w) The MR brain imaging was reviewed by 2 Neuroradiologists and consensus was reached on all reported imaging abnormalities. We also reviewed the results of the Neurodevelopmental assessments (Bayley Scales of Infant and Toddler Development – Bayley III) performed at 18 months as part of the study. No statistical hypothesis was tested.

Results
The main incidental findings included intracranial haemorrhage (23.4%), punctate white matter lesions (PWMLs) (12.4%) and caudothalamic subependymal cysts (9.6%). Subdural haemorrhage was the most common type of intracranial haemorrhage (21.6%). Subdural haemorrhage and PWMLs were more common in ventouse-assisted deliveries compared with Caesarean section deliveries (57% vs 2% and 24% vs 6%, respectively). Acute infarcts were noted in 5 infants (1%). Other incidental findings included mild ventricular dilatation (2%), arachnoid cysts (0.6%) and Developmental venous anomalies (0.8%). The results of the Bayley Scales of Infant and Toddler Development (Bayley III) were: Cognitive score, Mean 99.88 (SD 10.8); Language score: 96.3 (15.2); and Motor score, 101.8 (9.3). Overall 97% of the newborns scored greater than 2SD below the mean.

Conclusions
This study describes the prevalence of incidental findings on MRI brain imaging in a large group of low risk term newborns with normal outcomes. These results can serve as a future reference for the interpretation of incidental findings in clinical and research term neonatal brain MR imaging.

References
http://www.developingconnectome.org