Gestational age‐related changes in relaxation times of neonatal brain by quantitative synthetic magnetic resonance imaging

Abstract

Objective: This study aimed to explore the correlation between T1 and T2 relaxation times of synthetic MRI (SyMRI) and gestational age (GA) in each hemisphere of preterm and term newborns at the initial 28 days of birth. Methods: Seventy preterm and full-term infants were prospectively included in this study. All subjects completed 3.0 T routine MRI and SyMRI (MAGiC) one-stop scanning within 28 days of birth (aged 34-42 W at examination). The SyMRI postprocessing software (v8.0.4) was used to measure the T1 and T2 relaxation values of each brain region. The linear regression equations of quantitative relaxation values with GA were established to compare the variation speed in each brain region. Results: A significant linear and negative correlation was found between relaxation times and GA in the neonate cerebral cortex and subcortical gray and white matter regions (All p<.05). The relaxation time of the left centrum semiovale decreased with maximum variance with increasing GA among all white matter regions (T1: b = -51.45, β = -0.65, p < .0001; T2: b = -8.77, β = -0.71, p < .0001), whereas the right posterior limb of internal capsule showed minimal variance (T1: b = -27.94, β = -0.60, p < .0001; T2: b = -3.25, β = -0.68, p < .0001). Among all gray matter regions, the right globus pallidus and thalamus indicated the most significant decreasing degree of T1 and T2 relaxation values with GA (right globus pallidus T1: b = -33.14, β = -0.64, p < .0001; right thalamus T2: b = -3.94, β = -0.81, p < .0001), and the right and left occipital lobes indicated the least significant decreasing degree of T1 and T2 relaxation values with GA, respectively (right occipital lobes T1: b = -11.18, β = -0.26, p = .028; left occipital lobes T2: b = -1.22, β = -0.27, p = .024).Conclusions: SyMRI could quantitatively evaluate the linear changes of T1 and T2 relaxation values with GA in brain gray and white matter of preterm and term neonates.

Quantitative assessment of preoperative brain development in pediatric congenital heart disease patients by synthetic MRI

“…Vanderhasselt et al reported that neonates with severe postnatal disorders had prolonged local tissue relaxation times, particularly in the PLIC and the central portion of the CS, which had the highest accuracy in predicting at-risk status [ 20 ]. Recent studies have shown that the T1 and T2 relaxation values obtained by SyMRI are closely related to the degree of myelin development, which can reflect subtle differences in early brain development and is an effective indicator for assessing brain maturity [ 8 ]. In this study, we quantitatively assessed the preoperative brain development of infants and children with CHD by SyMRI, compared the differences in relaxation values between the two groups of subjects in different brain regions, and analyzed the correlation between the significantly different parameter values and Gesell development scores.…”

“…Synthetic magnetic resonance imaging (SyMRI) is an emerging imaging modality that facilitates quantitative analysis of tissues by simultaneously obtaining multiple contrast images and multiple quantitative maps in a single scan over a short period. Studies on quantitative relaxation values in the central nervous system have been reported in the literature [ 6 – 8 ]. Quantitative information, such as longitudinal relaxation time (T1) and transverse relaxation time (T2) relaxation values, which can reflect changes in the myelin content of the brain, can aid imaging physicians in the detection of subtle brain lesions.…”