Intracranial cavity volume can be accurately estimated from the weights of intracranial contents: confirmation by the dental plaster casting method

Intracranial cavity volume is used to evaluate brain size relative to the intracranial space. This volume can theoretically be obtained from the weights and densities of the brain and surrounding cerebrospinal fluid (weight method). However, the accuracy of this method has not been examined. In this study, we examined the reliability of the weight method, by comparing the intracranial cavity volumes of 41 post-mortem cases obtained by the weight method (ICVw) with those obtained by a dental plaster casting method (ICVcast) which was shown to be unbiased. The ICVw was not significantly different from the ICV cast (P = 0.49, paired t-test), and the standard error of difference was 18 ml (1.3% of ICVcast). These results show that the weight method is reliable, and applicable to routine autopsies.