Acute CT Brain
Brain CT quality and artifacts

CT brain image quality depends on the quality of the CT scanner, the skills of the radiographer, and the cooperation of the patient. There are common artifacts that should be taken in to consideration when viewing CT brain images. Some of these artifacts are unavoidable.

Medical artifacts

As with assessment of any radiological investigation, the presence of medical artifacts should be noted.

Movement artifact

Agitated patients may move during the acquisition of CT images. It may be difficult to exclude pathology if there is movement artifact and selected images may need to be repeated.

Beam-hardening and scatter artifact

CT images of the brain often show dark or bright streaks. These are most commonly seen as lines running between two dense parts of the skull, such as the prominences of the inner table of the skull, or between the petrous bones.

These artifacts are partly due to scattering of the X-ray beam and partly due to alteration of the average power of the X-ray beam as it passes through relatively dense structures.

Single slice v image stack

It is important to view CTs of the brain as a stack of images, and not to assess a single slice in isolation of those above or below it.

Contrast enhancement

Administration of intravenous contrast material may provide additional information regarding pathological processes seen on CT brain images. Usually a non-contrast CT is performed first and if there is an abnormality that is thought to represent a solid or cystic mass lesion then, assuming there are no contraindications, intravenous contrast may be given and the scan repeated.