Brain and Ventricles in Very Low Birth Weight Infants at Term: A Comparison Among Head Circumference, Ultrasound, and Magnetic Resonance Imaging

Abstract

OBJECTIVES. The aim of this study was to assess the relationship among the size of the lateral ventricles, head-circumference measure, and brain volumes. In addition, the association between ventricular dilatation and various brain lesions was defined. PATIENTS AND METHODS. A total of 257 preterm very low birth weight (≤1500 g) infants who met the inclusion criteria were born in Turku University Central Hospital between 2001 and 2006. A total of 209 (84.8%) of 218 survivors participated in the study. The measurements at term included the ventricular brain ratio, the widths of the frontal and occipital horns of the lateral ventricles by ultrasound, total and regional brain volumes by MRI, and head circumference. Brain lesions were defined by ultrasound at 3 to 5, 7 to 10, and 30 days of age monthly until discharge and by MRI and ultrasound at term. RESULTS. An abnormal ventricular brain ratio (>0.35), an increasing number of dilated ventricular horns, and smaller head circumference were significantly associated with smaller total brain tissue volume. The abnormal ventricular brain ratio and the increasing number of dilated ventricular horns in ultrasound associated with larger ventricular volumes in MRI, and a smaller head circumference was associated significantly with reduced regional brain tissue volumes. Brain lesions were more common in infants with ventriculomegaly. CONCLUSIONS. The ventricular brain ratio, widths of the lateral ventricular horns, and head circumference are appropriate measures for the estimation of both total and regional brain tissue volumes. Ventriculomegaly is strongly associated with brain lesions.