Contrast mechanism used in fMRI based on paramagnetic deoxyhaemoglobin
Expansion
Blood-Oxygen-Level Dependent
Purpose
Enables non-invasive functional brain mapping
Clinical Context
BOLD exploits susceptibility differences between oxygenated and deoxygenated blood. Active areas have higher oxygenation, lower susceptibility effects, appearing bright in gradient-echo fMRI.
Related Terms
- fMRI
- Brain activation
Key Points
- BOLD effect detects oxygenation changes with neural activity; allows task-based or resting-state fMRI