Predicting developmental outcomes in preterm infants: A simple white matter injury imaging rule

Abstract

Objective: To develop a simple imaging rule to predict neurodevelopmental outcomes at 4.5 years in a cohort of preterm neonates with white matter injury (WMI) based on lesion location and examine whether clinical variables enhance prediction.

Methods: Sixty-eight preterm neonates born 24-32 weeks' gestation (median 27.7 weeks) were diagnosed with WMI on early brain MRI scans (median 32.3 weeks). 3D T1-weighted images of 60 neonates with 4.5-year outcomes were reformatted and aligned to the posterior commissure-eye plane and WMI was classified by location: anterior or posterior-only to the midventricle line on the reformatted axial plane. Adverse outcomes at 4.5 years were defined as Wechsler Preschool and Primary Scale of Intelligence full-scale IQ <85, cerebral palsy, or Movement Assessment Battery for Children, second edition percentile <5. The prediction of adverse outcome by WMI location, intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), and retinopathy of prematurity (ROP) was assessed using multivariable logistic regression.

Results: Six children had adverse cognitive outcomes and 17 had adverse motor outcomes. WMI location predicted cognitive outcomes in 90% (area under receiver operating characteristic curve [AUC] 0.80) and motor outcomes in 85% (AUC 0.75). Adding IVH, BPD, and ROP to the model enhances the predictive strength for cognitive and motor outcomes (AUC 0.83 and 0.88, respectively). Rule performance was confirmed in an independent cohort of children with WMI.

Conclusions: WMI on early MRI can be classified by location to predict preschool age outcomes in children born preterm. The predictive value of this WMI classification is enhanced by considering clinical factors apparent by term-equivalent age.

Figure 1. White matter injury (WMI) identification method

(A) Bilateral punctate WMI in an unformatted image seen in the axial, sagittal, and coronal planes. (B) Identification and alignment of the posterior commissure (PC), left eye (LE), and right eye (RE) on the same plane in the axial T1-weighted image and sagittal T1-weighted image. (C) Axial images at the level immediately above the curving of the ventricles, with punctate WMI located posterior to the midventricle line in green (left) and located both anterior and posterior to the midventricle line (right).

Figure 2. Borderline cases

Reformatted axial T1-weighted images at the level immediately above the curving of the ventricles, showing punctate white matter injury (WMI) adjacent to the midventricle line (green). The image on the left (A) was classified by both raters as posterior-only. It is important to note that although only a few punctate lesions are seen on this slice, total WMI volume for this subject was 480.69 mm³. This child had normal cognitive and motor outcomes. The image on the right (B) was a case of disagreement among raters due to the right-sided hyperintensity (arrow) abutting the midventricle line and was classified as posterior-only after measurement of ventricle length. This child had a normal cognitive and an adverse motor outcome.