Regional cerebral blood flow in children from 3 to 5 months of age

Abstract

Background and purpose: Understanding the relationship between brain and behavior in early childhood requires a probe of functional brain development. We report the first large study of regional CBF by use of arterial spin-labeling in young children.

Materials and methods: Cerebral blood flow by use of arterial spin-labeling was measured in 61 healthy children between the ages of 3 and 5 months. Blood flow maps were parcellated into 8 broadly defined anatomic regions of each cerebral hemisphere.

Results: There was no sex effect; however, group analysis demonstrated significantly greater CBF in the sensorimotor and occipital regions compared with dorsolateral prefrontal, subgenual, and orbitofrontal areas (P < .0001). A significant age effect was also identified, with the largest increase in blood flow between 3 and 5 months occurring in the following regions: orbitofrontal (P < .009), subgenual (P < .002), and inferior occipital lobe (P = .001).

Conclusions: These results are consistent with prior histologic studies demonstrating regional variation in brain maturation and suggest that arterial spin-labeling is sensitive to regional as well as age-related differences in CBF in young children.

Fig 1.

A and B, Brain segmentation process of the 9-month template is shown; C, 4-month T1 image; D, corresponding atlas after mathematica transformation. E, CBF image; F, CBF image with the atlas overlaid to demonstrate how well they are registered; G, the 8 segments projected onto the cortical surface.

Fig 2.

Regional differences in CBF. Although there were no significant differences within the 3 higher flow regions (sensorimotor, parieto-occipital, and inferior-occipital; P = .43) or within the 3 lower flow regions (subgenual, orbito-frontal, and dorsolateral prefrontal; P = .15), mean CBF between the high and low groups was highly significant. The mixed model fit age in a continuous manner, but, for illustrative purposes, age is split at the median. Horizontal dotted line is the median CBF value across all regions and ages.

Fig 3.

Regions with CBF above study population median are shown in shades of red and those regions with CBF below the median are shown in shades of blue. Darker color indicates greater deviation from the median flow. Thus, the sensorimotor (SM) region had the highest flow above the median and the dorsolateral prefrontal (DLPF) region had the lowest flow below the median.

Fig 4.

Cerebral blood flow versus age within each region; ρ is Spearman rank correlation coefficient.