Expand ("E")   Collapse

Age: 48

Sex: Male

Indication: Unresponsive

Pseudo-Subarachnoid Hemorrhage

Mimicking True Subarachnoid Hemorrhage

Findings Relating to the Mimic

  • Diffuse sulcal effacement and symmetric hypoattenuation and loss of gray-white differentiation throughout the supratentorial and infratentorial brain with basal cisternal hyperattenuation favored to reflect pseudosubarachnoid hemorrhage. Symmetric effacement of the ventricular system.


  • In the setting of diffuse cerebral edema, the basal cisterns, falx and tentorium can appear hyperdense.
  • Typically the attenuation value is less than that of true subarachnoid hemorrhage (in the reference listed below, pseudo-SAH ranged from 29 to 33 HU versus 60 to 70 in true SAH).
  • Potentially secondary to a combination of cerebral edema in the surrounding parenchyma, displacement of CSF in the extra-axial space, and engorgement of superficial vessels.

📣 Feedback?

⌨️  Keyboard Shortcuts ("K")

⌨️ Keyboard Shortcuts

View shortcuts


  Full screen




  Save the case

  Close case/tab

Previous Slice (Scroll)

Next Slice (Scroll)

 Toggle presets

 Previous series (if multiple)

 Next series (if multiple)

  Previous case (⌘ ◄ on a mac)

  Next case (⌘ ► on a mac)