blood-brain barrier
Selective physiological barrier that restricts passage of substances from blood to brain tissue, visible on imaging when disrupted.
Full Definition
The blood-brain barrier (BBB) is a highly selective physiological barrier formed by specialized endothelial cells in brain capillaries that restricts the passage of substances from the bloodstream into the central nervous system. This barrier protects the brain from potentially harmful substances while allowing essential nutrients to pass through. In neuroimaging, BBB integrity is assessed through contrast enhancement patterns, as gadolinium-based agents normally cannot cross an intact barrier. BBB disruption, indicated by abnormal contrast enhancement, is a key imaging finding in various pathological conditions including tumors, infections, inflammation, and stroke.
Usage
Usage note: Always hyphenate; may be abbreviated as BBB after first use.
In Context
- "The contrast enhancement pattern suggests blood-brain barrier breakdown in this region." — Imaging interpretation
- "Blood-brain barrier disruption is an early finding in multiple sclerosis lesions." — Pathophysiology discussion