Diagnostic Imaging Pathways - Stroke

Pathway

Images

Image Gallery Note: These images open in a new page
1a		Ischaemic Stroke Image 1a (Computed Tomography): Acute ischaemic stroke in the right middle cerebral artery territory (arrow).
1b		Ischaemic Stroke Image 1b : Post-mortem specimen ( of a different patient) showing embolic infarct in the region of right middle cerebral artery.
2		Ischaemic Stroke Image 2 (Computed Tomography): Acute ischaemic stroke in the right posterior inferior cerebellar artery territory (arrow) with compression of the fourth ventricle.
3		Haemorrhagic Stroke Image 3 (Computed Tomography): Acute intracranial haemorrhage secondary to a ruptured left arteriovenous malformation (AVM).
4		Haemorrhagic Stroke Image 4 : Post-mortem specimen showing a hypertensive intracerebral haemorrhage in the region of the left thalamus and extending into the lateral ventricles.
5		Old Cystic Infarct Image 5 : Post-mortem specimen showing an old cystic infarct in the left middle cerebral artery territory. Old infarcts appear as cystic spaces of varying size, depending on the size of the artery occluded (an old infarct undergoes liquefactive necrosis and may become a fluid-filled cyst).
6		Dense MCA Sign Image 6: Non-contrast CT head demonstrates dense M1 segment of middle cerebral artery (MCA) [arrow] on the left side. Dense MCA reflects a thrombus causing occlusion of left M1 segment of MCA.
7		Occluded left M1 MCA Image 7: CT Angiogram of head and neck demonstrates occlusion of M1 segment of left middle cerebral artery secondary to thrombus.
8a		Occluded left M1 MCA Image 8a: Catheter Cerebral Angiogram (Digital Subtraction Angiogram) demonstrates no blood flow through occluded left M1 middle cerebral artery prior to mechanical thrombectomy.
8b		Recanalisation of left MCA Image 8b: Catheter Cerebral Angiogram in same patient as image 8a demonstrating recanalization of left MCA and restoration of blood flow after mechanical thrombectomy.

Teaching Points

Teaching Points

• Imaging in the setting of suspected stroke serves a number of purposes
  • To distinguish between haemorrhagic and ischaemic stroke
  • To determine vascular territory of stroke and location and extent of intravascular clot
  • To determine presence and extent of ischaemic core and penumbra
  • To determine aetiology of the stroke
  • To identify alternative causes of clinical symptoms
• A non-contrast CT is the initial imaging modality of choice in suspected stroke. The main value of CT in the acute setting is to exclude haemorrhage or tumour
• Further imaging is dictated by the clinical situation and includes CTA (CT Angiogram) +/- CTP (CT Perfusion) depending on resources and expertise available. CTA/CTP should can be performed while recombinant tissue plasminogen activator (rtPA) is being prepared and should not delay the administration of recombinant tissue plasminogen activator
• For patients who are outside the time window for acute reperfusion therapies [ > 4.5 hours at sites where only IV recombinant tissue plasminogen activator (rtPA) is being considered; > 8hours at sites where endovascular therapy is considered] and for patients with Transient Ischaemic Attack (TIA) , emphasis is on secondary prevention and their imaging work-up should be focused on vascular imaging (MRA or Carotid Doppler or CTA) to assess carotid arteries as a possible source of emboli with secondary prevention in mind. If MRA is obtained, DWI, T1, T2 sequences should be performed as well at the same time

References

References

Date of literature search: May 2016

The search methodology is available on request. Email

References are graded from Level I to V according to the Oxford Centre for Evidence-Based Medicine, Levels of Evidence. Download the document

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