Figure 2a. Graphs depict age-related volume changes in (a) intracranial space and (b) whole brain in our 116 healthy volunteers. Volume intercepts at birth are based on quantitative MR imaging findings of Huppi et al (55). (c) Graph shows that our in vivo age-related intracranial space growth rates are similar to those of previous postmortem studies (table 115 in the study by Blinkov and Glezer [19]; Lichtenberg [20]). (d) Graph shows similar growth rates in our in vivo whole brain volume (red symbols), estimated in vivo whole brain weight (black symbols; estimated whole brain weight = brain weight + CSF weight), and brain weight (open symbols) from 11 previously published postmortem studies (tables 111, 113, 115, 117, 119 in reference 19) (41-46). In the present study and in each published study, volume or weight at each age is plotted as a function of a percentage of the maximum volume or weight for that study. Postmortem weight includes CSF, but our in vivo MR imaging whole brain volume does not. Therefore, during development, CSF weight makes a small contribution to the reported brain weight, but, with aging, its weight makes a successively greater contribution. (On x axes, age scales change after 20-year point.)