Age-Dependent Signal Intensity Changes in the Structurally Normal Pediatric Brain on Unenhanced T1-Weighted MR Imaging

Abstract

BACKGROUND AND PURPOSE: Various pathologic and nonpathologic states result in brain parenchymal signal intensity changes on unenhanced T1-weighted MR imaging. However, the absence of quantitative data to characterize typical age-related signal intensity values limits evaluation. We sought to establish a range of age-dependent brain parenchymal signal intensity values on unenhanced T1WI in a sample of individuals (18 years of age or younger) with structurally normal brains. MATERIALS AND METHODS: A single-center retrospective study was performed. Gadolinium-naïve pediatric patients with structurally normal MR brain imaging examination findings were analyzed (n = 114; 50% female; age range, 68 days to 18 years). ROI signal intensity measurements were obtained from the globus pallidus, thalamus, dentate nucleus, pons, and frontal lobe cortex and subcortical white matter. Multivariable linear regression was used to analyze the relationship between signal intensity values and age. RESULTS: Results demonstrated a statistically significant association between signal intensity values and linear age in all neuroanatomic areas tested, except the frontal gray matter, (P , .01). There were no statistically significant differences attributable to patient sex. CONCLUSIONS: Age-dependent signal intensity values were determined on unenhanced T1WI in structurally normal pediatric brains. Increased age correlated with increased signal intensity in all brain locations, except the frontal gray matter, irrespective of sex. The biologic mechanisms underlying our results remain unclear and may be related to chronologic changes in myelin density, synaptic density, and water content. Establishing age-dependent signal intensity parameters in the structurally normal pediatric brain will help clarify developmental aberrations and enhance gadolinium-deposition research by providing an improved understanding of the confounding effect of age.

The switch from Gd-DTPA to Gd-DOTA is not associated with decrease of the T1 signal intensity of the pallidus and dentate in a pediatric population

“…Third, due to the frequent location of pediatric tumors of the central nervous system in the posterior cranial fossa, in our series we could assess the dentate nucleus in a smaller number of cases than the globus pallidus. However similar effects of GBCAs and age on the T1 SI of these two nuclei are established (1)(2)(3)(4)(5)(6)32) and were partially observed after the switch in the present study.…”

“…Of the 57 control patients without prior CE-MRI scans, 45 were excluded due to the above exclusion criteria and 19 were excluded because the MRI showed brain abnormalities. Since age is associated with increasing T1 SI in the pallidus and caudate (31,32), we finally assessed GM nuclei T1 SI in three groups of age-matched patients: nine patients with at least six cumulative administrations of GBCA who switched from Gd-DTPA to Gd-DOTA; 18 patients who had received at least six administrations of GD-DOTA; and nine control patients without prior administrations of GBCA.…”

Maternal deprivation and milk replacement affect the integrity of gray and white matter in the developing lamb brain

“…The mean T1w signal intensity was calculated for each GM, WM, and CSF segmentation. The mean CSF value was used to normalise that of GM and WM, as previously done in a pediatric study (Flood et al., 2019).…”

“…This is a relevant indicator of early GM and WM maturation because changes in T1w signal intensity can reflect a decrease in water content and an increase in macromolecules in the brain (Barkovich et al, 1988;Shroff et al, 2010). Based on data reported in humans (Barkovich et al, 1988;Flood et al, 2019;Serag et al, 2011;Westlye et al, 2010), we hypothesized higher values in WM than in GM and increasing values in both brain tissues throughout development of mother-reared lambs. We found the highest values of T1 signal intensity in the WM, which were 1.5 times greater than those measured in GM whatever the timepoint of acquisition.…”

“…Magnetic resonance imaging (MRI) enables longitudinal investigation of various morphometric and microstructural indicators of brain maturation. In particular, T1-weighted (T1w) signal intensity (Flood et al, 2019;Luby et al, 2013) and diffusion tensor imaging (DTI) parameters (Dubois et al, 2006(Dubois et al, , 2014Hüppi & Dubois, 2006) have been used to quantify maturation of the growing brain. Based on studies in humans (Deoni et al, 2013;Luby et al, 2013) and nonhuman primates (Liu et al, 2019), we examined the longitudinal impact of maternal deprivation on these morphometric and microstructural characteristics of the lamb brain.…”