Gliosis: Meaning in a Radiology Report

Gliosis

Also written as: gliotic changes, glial scar, astrogliosis

Gliosis is scar-like tissue the brain forms where it was injured before, for example by a stroke, head injury, infection or surgery.

Seen on: MRI

How it reads in a report

Small area of gliosis in the right frontal lobe at the site of the previous contusion, unchanged since the prior MRI.

What it means

Nerve cells lost from the brain are not replaced. Instead, support cells called glia multiply and fill in the injured area, much like a scar forms in skin. This tissue holds more water than healthy brain, so it looks bright on T2 and FLAIR MRI images. Gliosis often surrounds an area where tissue was lost, called encephalomalacia.

When it matters

Gliosis usually marks an old injury that has healed, not active disease, and it tends to stay the same over time. Small scattered spots in the white matter are common with age and are often linked to small vessel disease. A larger area matters mainly for its cause, which your history often explains. Older scans help confirm it is stable. Scars near the brain surface can occasionally be a source of seizures.

Questions to ask your doctor

What most likely caused this gliosis: an old injury or small vessel changes?
Has it changed compared with my older scans?
Could this scar be linked to any of my symptoms, such as seizures?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.