Concept 1 / 1
Key Concepts to Memorize
The brain's resource demands:
- Only 2% of body weight but consumes a disproportionately high share of O2 and nutrients
- Requires a continuous supply of blood (via arteries); waste removed via veins
- Blood circulation serves two roles: (A) Delivery of O2/nutrients, (B) Clearance of waste (amyloid, tau, CO2)
Cerebral Small Vessel Disease (cSVD):
- = damage to small blood vessels in the brain
- 5 MRI markers of cSVD:
1. White matter hyperintensities
2. Lacunes
3. Microbleeds
4. Perivascular spaces
5. Atrophy
- Prevalence: affects 90% of subjects in late life, 20–50% in midlife
- Clinical impact:
- Present in 50% of dementia cases (incl. Alzheimer's)
- Primary contributor to vascular dementia (2nd most common dementia)
- Behind 80% of intracerebral haemorrhages in late life
- Cause of 25% of ischaemic strokes worldwide
Key concept: asymptomatic → tipping point → symptomatic
- cSVD damage accumulates silently (tolerable) until a tipping point → stroke or dementia (intolerable)
- Goal: detect and intervene _before_ the tipping point
CIR Lab research focus (2 pillars):
1. Quantification — AI-powered tools to describe cSVD quantitatively
2. Modelling — disentangle cSVD complexity; phenotyping, staging, clinical implications
Supervised vs. Unsupervised Learning (Bernal's AI intro):
- Supervised: find a function that maps input features → labels (e.g., classify animal species)
- Unsupervised: find groups based on similarities in input features, with no labels
Domain Randomisation (key specific project):
- Problem: not enough real patient data + not enough variability → model doesn't generalize
- Solution: simulate your own training data with random variations
- Particularly useful when shapes are somewhat consistent across subjects (e.g., brain lesions)
- Advantages: no need for real patient data or manual annotations; train with many varied images
- Disadvantage: the data generation model must be realistic enough — if it's too far from real-world data, the trained model won't transfer