Stroke (summary)
This is a basic article for medical students and other non-radiologists
Stroke is a clinical diagnosis where an acute neurological deficit follows a cerebrovascular insult. There are two main groups of stroke: ischemic (>80%) or hemorrhagic (<20%) 1.
On this page:
Reference article
This is a summary article; read more in our article on stroke.
Summary
- anatomy
-
epidemiology
- common
- leading cause of disability
- third highest cause of mortality in the UK 2,3
-
presentation
- sudden neurological deficit
- manifest symptoms depend on the vascular territories involved
- time of onset is important when considering treatment
-
pathophysiology
- brain parenchyma is deprived of blood flow and therefore oxygen
- ischemic
- arteries occluded by thrombus or embolus
- temporary loss of blood flow may occur (TIA)
- cell death results in edema and swelling
-
investigation
- non-contrast CT head in the first instance
- exclude hemorrhage or other cause
- may show hyperdense vessel or evidence of infarction
- CT angiography
- some centers use this to identify blockages and assess collaterals when planning clot retrieval
- MRI
- less commonly used for acute events, but good for identifying infarcts (especially using DWI sequences)
- ultrasound
- carotid Doppler ultrasound in the peri-stroke period to select patients who may benefit from endarterectomy
- non-contrast CT head in the first instance
-
treatment
- thrombolysis or thrombectomy
- ischemic strokes <4.5 hours old
- depends on the local protocol
- should be discussed with an acute stroke service
- stroke patients should be managed in a stroke center
- oral antiplatelet therapy
- medical management of hypertension and risk factor reduction
- thrombolysis or thrombectomy
Imaging
-
role of imaging
- is there evidence of stroke?
- what is the distribution and severity of the stroke?
- is there hemorrhagic transformation?
- is a cause visible, e.g. in situ thrombus?
- are there contraindications to IV thrombolysis?
- are there indications for clot-retrieval?
- is there significant carotid stenosis?
-
radiographic features
- CT
- parenchymal infarction may not be visible in the acute setting
- with time, cytotoxic edema causes reduced density on CT
- clot within a vessel may be seen as hyperdensity
- acute hemorrhage will appear dense
- MRI
- the most important sequence is the DWI (diffusion sequence)
- diffusion restriction in this context is highly sensitive for ischemia
- angiography (CTA/MRA/DSA)
- assessment of arterial supply to confirm whether a clot is present
- perfusion (CT/MRI)
- assessment of ischemic/infarcted areas
- ischemia may be reversible
- carotid Doppler
- not in the acute setting but usually within two weeks following onset
- assessment of the neck vessels looking for carotid stenosis
- if >70% stenosis on affected side, surgery may be offered
- CT
Related Radiopaedia articles
Medical student radiology curriculum
- radiology for students
-
neuroradiology
- imaging
- key findings
- conditions
- presentations
- cardiac radiology
-
chest radiology
- imaging
- key findings
- conditions
- presentations
-
abdominal radiology
- imaging
- key findings
- conditions
- upper GI
- lower GI
- hepatopancreatobiliary
- genitourinary
- vascular
- breast
- presentations
-
musculoskeletal radiology
- imaging
- key findings
- interpretation
- conditions
- upper limb
- lower limb
- pelvic fractures
- proximal femoral fractures
- distal fibula fracture
- 5th metatarsal fracture
- pediatrics
- spine
- major trauma
- joint pain/arthritis
- presentations
- upper limb
- lower limb
- hip trauma
- lower limb injury
- foot and ankle injury
- joint pain/arthritis
-
obstetrics and gynecology imaging
- imaging
- pelvic US - transabdominal
- pelvic US - transvaginal
- hysterosalpingogram
- CT abdomen
- MRI pelvis
- key findings
- endometrial thickening
- ovarian cysts
- conditions
- non-obstetric
- pelvic inflammatory disease
- tubo-ovarian abscess
- ovarian torsion
- ovarian neoplasms
- endometriosis
- endometrial hyperplasia
- endometrial carcinoma
- cervical cancer
- obstetric
- normal pregnancy
- abnormal first trimester
- ectopic pregnancy
- heterotopic pregnancy
- twins
- non-obstetric
- presentations
- PV bleeding
- pelvic pain
- PV discharge
- early pregnancy
- imaging
-
pediatric radiology
- imaging
- key findings
- conditions
- presentations