Incidental Findings on Brain Magnetic Resonance Imaging in Preterm Infants.

BACKGROUND: In recent years, many neonatal intensive care units have adopted the practice of routinely performing brain magnetic resonance imaging (MRI) of extremely preterm (EP) infants at term-equivalent age (TEA). This practice may result in increased identification of incidental findings (IF).

OBJECTIVES: To determine the prevalence and clinical significance of incidental findings on routine MRI of EP infants.

METHODS: We retrospectively reviewed findings on routine brain MRI on 165 EP infants at TEA (gestation < 28 weeks) admitted between June 2015 and December 2017.

RESULTS: Incidental findings were detected in 16/165 (9.7%) infants. This included 9 cases that were clinically significant: 7 (with upper spinal cord abnormalities in 3, a choroid plexus lesion in 1, a pituitary abnormality in 1, and cerebral aqueduct narrowing in 2) required diagnostic intervention, and 2 (1 with an extramedullary arachnoid cyst and 1 with endolymphatic sac dilatation with a hypoplastic cochlear nerve) required diagnostic and therapeutic interventions. The incidental findings in the other 7 cases (a venous anomaly in 2, corpus callosum dysgenesis in 1, an absent septum pellucidum in 2, a frontal scalp mass in 1, and a nasal septum cyst in 1) were not clinically significant.

CONCLUSIONS: Incidental findings were not uncommon on routine brain MRI of EP infants at TEA in our cohort. While most were clinically insignificant, some did require further diagnostic and therapeutic interventions. Prospective large studies on the prevalence and clinical significance of incidental findings on routine brain MRI of EP infants at TEA are required for developing evidence-based management plans and for counselling parents.