26. Neuroradiology. Imaging of acute intracranial vascular diseases. Stroke.
- Ischaemic stroke
- Gold standard: Multimodal CT evaluation
- Non-contrast CT
- CT angiography
- CT perfusion
- Diffusion weighted MRi
- Shows ischaemia within minutes
- Ischaemia causes decreased tissue water diffusion
- Phases
- Acute phase
- CT cannot reliably detect ischaemia this early (< 24 hours)
- However, CT may detect the embolus itself (hyperdense artery, often middle cerebral a.)
- Subacute phase (after 12-24 hours)
- Ischaemic tissue is hypodense
- Ischaemic tissue swells -> mass effect
- Chronic phase (after days)
- Ischaemic tissue becomes less hypodense (but is still hypodense)
- Acute phase
- Gold standard: Multimodal CT evaluation
- Haemorrhagic stroke
- Gold-standard: Multimodal CT evaluation
- Non-contrast CT
- CT angiography
- CT perfusion
- Phases
- Acute phase (< 24 hours)
- Hyperdense (blood)
- Subacute phase (after 24 hours)
- Isodense with brain
- Chronic phase (after days)
- Hypodense
- Acute phase (< 24 hours)
- Gold-standard: Multimodal CT evaluation
- Brain aneurysm
- CT or MR angiography