Increased density of tentorium and falx: a false positive CT sign of subarachnoid hemorrhage

Can Assoc Radiol J. 1986 Dec;37(4):243-7.


Noncontrast computed tomographic (CT) findings in 10 patients with profound brain swelling or a mass effect revealed a high density of the falx and tentorium and thus suggested subarachnoid hemorrhage. Postmortem examinations performed shortly after the CT scans demonstrated no subarachnoid blood. A review of 100 CT scans drawn at random was carried out to assess the frequency of a hyperdense, noncalcified falx in the same population and failed to demonstrate this finding. Therefore, in the presence of profound brain swelling or a mass effect, factors other than subarachnoid hemorrhage may be responsible for increased density of the falx and tentorium on cranial CT head scans.

MeSH terms

  • Adult
  • Aged
  • Autopsy
  • Brain Edema / diagnostic imaging
  • Brain Neoplasms / diagnostic imaging
  • Cerebellum / diagnostic imaging*
  • Cerebral Infarction / diagnostic imaging
  • Diagnosis, Differential
  • Dura Mater / diagnostic imaging*
  • False Positive Reactions
  • Female
  • Humans
  • Intracranial Pressure
  • Male
  • Middle Aged
  • Subarachnoid Hemorrhage / diagnostic imaging*
  • Subarachnoid Hemorrhage / pathology
  • Tomography, X-Ray Computed*