MRI measurements of craniospinal and intracranial volume change in healthy and head trauma cases

The volumes of the intracranial space and the craniospinal system as a whole change during the cardiac cycle. These volume changes are caused by the pulsatile arterial inflow to the cranium, venous outflow, from the cranium, and cerebrospinal fluid (CSF) flow that oscillates back and forth between the cranium and the spinal canal. The volume changes can be measured accurately and reproducibly using a dynamic, motion-sensitive MRI technique. It appears intuitive that the volume change of the entire craniospinal system (CSVC) should be greater than the intracranial volume change (ICVC). However, since they exhibit varying temporal information, CSVC can be smaller than ICVC. In the present study, these volume changes were measured in healthy humans and trauma cases. In the trauma cases, it was found that CSVC was smaller than ICVC. The cause was found to be increased pulsatility in the venous flow channels. It is suspected that the resulting relationship between ICVC and CSVC is related to the incidence of trauma, and perhaps CSVC being smaller than ICVC could serve as an indicator.