gliosis
Pronunciation: glee-OH-sis
Proliferation of glial cells in response to brain injury, appearing as areas of increased signal intensity on MRI imaging.
Full Definition
Gliosis represents the brain's primary response to injury, characterized by the proliferation and hypertrophy of astrocytes and other glial cells. This reactive process occurs following various insults including trauma, infection, ischemia, radiation, or tumor infiltration. On magnetic resonance imaging, gliosis typically appears as areas of increased T2 and FLAIR signal intensity that may be difficult to distinguish from tumor recurrence or other pathological processes. While gliosis serves a protective function by forming glial scars to isolate damaged tissue, extensive gliosis can contribute to seizure development and neurological dysfunction.
Usage
Usage note: Distinguish from tumor recurrence, which may require advanced imaging techniques or biopsy for definitive diagnosis.
In Context
- "MRI demonstrated extensive gliosis in the right temporal lobe consistent with prior surgical resection and radiation therapy." — Follow-up imaging report