Sequelae of Premature Birth in Young Adults : Incidental Findings on Routine Brain MRI

Clin Neuroradiol. 2021 Jun;31(2):325-333. doi: 10.1007/s00062-020-00901-6. Epub 2020 Apr 14.

Abstract

Background and purpose: Qualitative studies about the abnormalities appreciated on routine magnetic resonance imaging (MRI) sequences in prematurely born adults are lacking. This article aimed at filling this knowledge gap by (1) qualitatively describing routine imaging findings in prematurely born adults, (2) evaluating measures for routine image interpretation and (3) investigating the impact of perinatal variables related to premature birth.

Methods: In this study two board-certified radiologists assessed T1-weighted and FLAIR-weighted images of 100 prematurely born adults born very preterm (VP <32 weeks) and/or at very low birth weight (VLBW <1500 g) and 106 controls born at full term (FT) (mean age 26.8 ± 0.7 years). The number of white matter lesions (WML) was counted according to localization. Lateral ventricle volume (LVV) was evaluated subjectively and by measurements of Evans' index (EI) and frontal-occipital-horn ratio (FOHR). Freesurfer-based volumetry served as reference standard. Miscellaneous incidental findings were noted as free text.

Results: The LVV was increased in 24.7% of VP/VLBW individuals and significantly larger than in FT controls. This was best identified by measurement of FOHR (AUC = 0.928). Ventricular enlargement was predicted by low gestational age (odds ratio: 0.71, 95% CI 0.51-0.98) and presence of neonatal intracranial hemorrhage (odds ratio: 0.26, 95% CI 0.07-0.92). The numbers of deep and periventricular WML were increased while subcortical WMLs were not.

Conclusion: Enlargement of the LVV and deep and periventricular WMLs are typical sequelae of premature birth that can be appreciated on routine brain MRI. To increase sensitivity of abnormal LVV detection, measurement of FOHR seems feasible in clinical practice.

Keywords: Diagnostic imaging; Lateral ventricles; Neuroradiology; Preterm birth; White matter diseases.