This investigation is directed to using the advances in MRI acquisition to focus on movement of blood through the arteries and veins of the brain and on the movement of CSF through certain passageways in such a way that actual volumes of fluid movement per millisecond can be calculated. Noam Alprin and others at his laboratory have developed this method over the last several decades so that the MR imaging device can be used to evaluate the dynamics of brain fluid circulation in patients with major neurological symptoms. In the course of these investigations a subject with a large skull defect due to injury was studied before having a closure plate installed and after the plate was installed. As can be seen in the “open skull” and “closed skull” data there are significant changes in the capacity of the skull system to accept a volume of the cardiac pulse. The pulse volume was reduced significantly after closure. That means the cardiac pulse volume entering the skull system is larger when the skull is open than when closed. In this case because the skull opening is rather large
The pulse volume in the open skull condition is twice that of the closed condition.This doesn’t mean that the pulse pressure is greater. Quite the contrary. There is less resistance to the volume of blood coming into the skull so the actual pulse volume can be larger Actually the skull opening allows the pulse pressure to be lower (the volume enters more easily) and the ICP to be lower along the same line as thedata presented by Ohara in the Japanese study.