Determinants of Indices of Cerebral Volume in Former Very Premature Infants at Term Equivalent Age

Abstract

Conventional magnetic resonance imaging (MRI) at term equivalent age (TEA) is suggested to be a reliable tool to predict the outcome of very premature infants. The objective of this study was to determine simple reproducible MRI indices, in premature infants and to analyze their neonatal determinants at TEA. A cohort of infants born before 32 weeks gestational age (GA) underwent a MRI at TEA in our center. Two axial images (T2 weighted), were chosen to realize nine measures. We defined 4 linear indices (MAfhlv: thickness of lateral ventricle; CSI: cortex-skull index; VCI: ventricular-cortex index; BOI: bi occipital index) and 1 surface index (VS.A: volume slice area). Perinatal data were recorded. Sixty-nine infants had a GA (median (interquartile range)) of 30.0 weeks GA (27.0; 30.0) and a birth weight of 1240 grams (986; 1477). MRI was done at 41.0 (40.0; 42.0) weeks post menstrual age (PMA). The inter-investigator reproducibility was good. Twenty one MRI (30.5%) were quoted abnormal. We observed an association with retinopathy of prematurity (OR [95CI] = 4.205 [1.231–14.368]; p = 0.017), surgery for patent ductus arteriosus (OR = 4.688 [1.01–21.89]; p = 0.036), early onset infection (OR = 4.688 [1.004–21.889]; p = 0.036) and neonatal treatment by cefotaxime (OR = 3.222 [1.093–9.497]; p = 0.03). There was a difference for VCI between normal and abnormal MRI (0.412 (0.388; 0.429) vs. 0.432 (0.418; 0.449); p = 0,019); BOI was higher when fossa posterior lesions were observed; VS.A seems to be the best surrogate for cerebral volume, 80% of VS.As’ variance being explained by a multiple linear regression model including 7 variables (head circumference at birth and at TEA, PMA, dopamine, ibuprofen treatment, blood and platelets transfusions). These indices, easily and rapidly achievable, seem to be useful but need to be validated in a large population to allow generalization for diagnosis and follow-up of former premature infants.

Ultrasonographic Estimation of Total Brain Volume: 3D Reliability and 2D Estimation. Enabling Routine Estimation During NICU Admission in the Preterm Infant

“…Interestingly, the intra- and interobserver agreement of the anteroposterior and vertical axis is almost perfect in our study. While our results for anteroposterior axis are consistent with the results obtained in other studies ( 6 , 21 ), we propose a systematic approach ensuring a 90 degrees angle among the anteroposterior axis and the vertical axis. Moreover, the proposed vertical axis takes into account the orientation of the sagittal view and the vermis anatomical landmarks, not the foramen magnum as suggested by Graça et al ( 12 ) as we did not want to add the distance of the cisterna magna to a measure of brain growth, given its physiologic variability.…”

Brain Volumes and Developmental Outcome in Childhood Following Fetal Growth Restriction Leading to Very Preterm Birth

“…Further, any stage of ROP was related to reductions in cerebellar cortex volumes and these relationships remained significant after adjustment for confounders. In a recent study, presence of ROP was associated with smaller biometric measurements and higher prevalence of brain abnormalities on term-equivalent age MRI ( Naud et al, 2017 ). We recently reported a relationship between any stage of ROP and reduced WM and cerebellar volume at term age as determined by MRI ( Sveinsdottir et al, 2018 ).…”

Visual Maturation at Term Equivalent Age in Very Premature Infants According to Factors Influencing Its Development

“…Cerebral imaging is interesting for assessing the development of vision ( Chau et al, 2013 ; Padilla et al, 2015 ; Naud et al, 2017 ). The cerebral volume seems related to visual development and the occurrence of abnormalities.…”

“…The cerebral volume seems related to visual development and the occurrence of abnormalities. Cerebral volume indices such as VSA, which is a standardized spherical surface area calculation ( Naud et al, 2017 ), was significantly associated with visual acuity in the multivariate analysis. Given the interest of the VSA and the link between the development of the posterior fossa and the retina, it would be helpful to develop an indicator of occipital brain volume development.…”

“…MRI was categorized as “MRI globally normal” or “MRI globally abnormal” when lesions were present, such as supra-tentorial injury (sequelae of germinal matrix hemorrhage, subependymal hemorrhage, and diffuse or cystic periventricular leukomalacia) and sub-tentorial or fossa posterior lesions. The following indices of cerebral volume were measured: CSI and VSA ( Naud et al, 2017 ).…”