CT Brain with or without Contrast

Computed tomography (also CAT or CT scan) of the brain (cerebral hemispheres, cerebellum and brain stem.)


A CT brain is ordered to look at the structures of the brain and evaluate for the presence of pathology, such as mass/tumor, fluid collection (such as an abcess), ischemic processes (such as a stroke). It is particularly good for hemorrhage, trauma or fracture to the skull and for hydrocephalus.

  • Bone abnormalities
  • Brain mass/tumor
  • Fluid collection, such as an abcess
  • Hemorrhage
  • Hydrocephalus
  • Ischemic process, such as a stroke
  • Trauma or fracture of the skull


  • CT of the brain can be done with or without contrast, but it is often not needed.
  • In general, it is preferred that the choice of contrast or no contrast be left up to the discretion of the imaging physician.


Without Contrast:

  • No preparation is required.

With Contrast:

  • Only one CT contrast study should be scheduled within a 48 hour period.
  • BUN & Creatinine must be done within 72 hours of the scan.
  • Nothing but clear liquid after midnight before the scan.
  • NPO 4 hours prior to exam (no food or drink).