gadolinium enhancement
Increased signal intensity on T1-weighted MRI following intravenous gadolinium-based contrast agent administration, indicating blood-brain barrier disruption or vascularity.
Full Definition
Gadolinium enhancement refers to the increased signal intensity observed on T1-weighted MRI sequences after intravenous administration of gadolinium-based contrast agents. In normal brain, the blood-brain barrier prevents gadolinium from entering the extracellular space, so enhancement indicates barrier disruption, increased vascularity, or lack of a blood-brain barrier. Enhancement patterns provide crucial diagnostic information: ring enhancement suggests necrotic centers with viable peripheral tissue, nodular enhancement indicates solid lesions with disrupted barriers, and linear enhancement may represent inflammation or infection. The timing, pattern, and degree of enhancement help differentiate between neoplastic, inflammatory, infectious, and vascular pathologies.
Usage
Usage note: Specify enhancement pattern (ring, nodular, linear) when describing pathology.
In Context
- "The lesion showed avid gadolinium enhancement with central necrosis, consistent with glioblastoma." — Neuro-oncology report
- "No gadolinium enhancement was observed, arguing against an active inflammatory process." — Multiple sclerosis evaluation