Development of Corpus Callosum in Preterm Infants Is Affected by the Prematurity: In Vivo Assessment of Diffusion Tensor Imaging at Term-Equivalent Age

Tatsuji Hasegawa,Masafumi Morimoto,Kenichi Isoda,Sachiko Tokuda,Takenori Tozawa,Kei Yamada,Shigemi Morioka,Aki Murakami,Akira Nishimura,Tomohiro Chiyonobu,Hajime Hosoi,Tsunehiko Nishimura

doi:10.1203/pdr.0b013e3182084e54

Tatsuji Hasegawa, Masafumi Morimoto + Show 10 more

Open Access

https://doi.org/10.1203/pdr.0b013e3182084e54

Copy DOI

Abstract

Callosal injury in preterm infants is a key factor affecting neurodevelopmental outcome. We investigated the characteristics of corpus callosum (CC) in preterm infants without apparent white matter lesions. We studied 58 preterm infants divided into three groups of 23-25, 26-29, and 30-33 wk GA. Diffusion tensor imaging (DTI) was obtained at term-equivalent age. The CC was parcellated into the genu, body, isthmus, and splenium. We measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of each CC subdivision using tractography and manual region of interest analysis. The cross-sectional areas were also measured. At the isthmus and splenium in the 23-25 GA group, the FA was significantly lower and the size was also significantly reduced. Furthermore, the FA and cross-sectional areas in the posterior CC decreased linearly with decreasing GA. There were no differences in FA and cross-sectional areas in other CC subdivisions, and no differences in ADC in any CC subdivisions, among the GA groups. We demonstrated that preterm infants without apparent white matter lesions affect development of the posterior CC depending on the degree of prematurity.

Highlights

Mortality rates of preterm infants have decreased in recent years primarily because of the development of neonatal intensive care [1,2]
There were no differences in fractional anisotropy (FA) and cross-sectional areas in other corpus callosum (CC) subdivisions, and no differences in apparent diffusion coefficient (ADC) in any CC subdivisions, among the GA groups
Sixty-four infants were excluded from the study, and the Abbreviations: ADC, apparent diffusion coefficient; CC, corpus callosum; Diffusion tensor imaging (DTI), diffusion tensor imaging; FA, fractional anisotropy; Magnetic resonance (MR), magnetic resonance; OL, oligodendrocyte; PVL, periventricular leukomalacia; ROI, region of interest; WM, white matter

Summary

Introduction

Mortality rates of preterm infants have decreased in recent years primarily because of the development of neonatal intensive care [1,2]. The degree of callosal injury in preterm infants is considered an important factor that strongly affects neurodevelopmental outcome. WM injury can result in lower FA and higher ADC This approach is useful in assessing microstructural WM injury and has been used in preterm infants at term-equivalent age (20 – 23). If the characteristics of callosal injury in preterm infants can be reliably assessed using DTI at term-equivalent age, this may allow prediction of later neurodevelopmental outcome. The aim of our study was to investigate whether callosal injury in preterm infants exhibits a characteristic distribution and a relationship with prematurity. Because the relationship between the degree of callosal injury and prematurity is unknown, we assessed the correlation between the measured parameters and GA at birth

Objectives

Methods

Results

Conclusion