=====Cranium===== see [[Cranial bone]] {{ ::cranium.jpg?400|}} see [[cranial]]. [[Intracranial pressure]] (ICP) is pressure inside the bony calvarium and therefore reflects the pressure of the [[brain parenchyma]] and [[cerebrospinal fluid]] (CSF). The [[Monro-Kellie hypothesis]] operates under the assumption that the [[cranium]] is incompressible and the volume inside the cranium is fixed ((Greitz D, Wirestam R, Franck A, Nordell B, Thomsen C, Ståhlberg F. Pulsatile brain movement and associated hydrodynamics studied by magnetic resonance phase imaging. The Monro-Kellie doctrine revisited. Neuroradiology. 1992;34(5):370-80. PubMed PMID: 1407513. )).