The sign refers to the presence of gas (pneumocephalus) between the tips of the frontal lobes with a heaped-up appearance giving the silhouette-like appearance of Mount Fuji 1-3. It suggests that the pressure of the gas is at least greater than that of the surface tension of cerebrospinal fluid between the frontal lobes 1-3. The sign is caused by cortical veins tethering the frontal lobes, resulting in their striking appearance 5.
The appearance of this sign often warrants immediate surgery to prevent permanent neurological damage. However, conservative management in patients with no signs of raised intracranial pressure has also been described 4.
- 1. Michel SJ. The Mount Fuji sign. Radiology. 2004;232 (2): 449-50. doi:10.1148/radiol.2322021556 - Pubmed citation
- 2. Heckmann JG, Ganslandt O. Images in clinical medicine. The Mount Fuji sign. N. Engl. J. Med. 2004;350 (18): 1881. doi:10.1056/NEJMicm020479 - Pubmed citation
- 3. Mattick A, Goodwin P. Mount Fuji sign on CT following trauma. J Trauma. 2005;59 (1): 254. J Trauma (link) - Pubmed citation
- 4. Sebastian B, Moideen J. Mount Fuji is Not as “Active” as We Think. (2018) Indian Journal of Neurosurgery. 77 (11): 880. doi:10.1055/s-0038-1667388 - Pubmed
- 5. Anne G. Osborn, Gary L. Hedlund, Karen L. Salzman. Osborn's Brain. (2017) ISBN: 9780323477765