Post on 11-Jan-2016
Stroke ImagingStroke Imaging
Dr Kneale MetcalfDr Kneale Metcalf
Stroke Physician (NNUHFT)Stroke Physician (NNUHFT)
OverviewOverview
Modalities availableModalities available When to use?When to use? TargetsTargets Real world imagingReal world imaging Future aspirationsFuture aspirations
Hyperacute StrokeHyperacute Stroke
Diagnosis difficultiesDiagnosis difficulties
Patient stability issuesPatient stability issues VomitingVomiting AirwayAirway Low GCSLow GCS SeizuresSeizures
CT ScanCT Scan
First time every timeFirst time every time ?? Posterior, late presentation?? Posterior, late presentation
FastFast SafeSafe
? Radiation? Radiation Available Available
CT ScannerCT Scanner
Early CT scanEarly CT scan
Give Radiologist correct informationGive Radiologist correct information TIME of onset neurologyTIME of onset neurology Side and details of neurologySide and details of neurology Associated headache?Associated headache? Trauma?Trauma? Anticoagulant?Anticoagulant? Relevant PMHRelevant PMH
CancerCancer StrokeStroke Neurosurgery / clips etc.Neurosurgery / clips etc.
Early CT scanEarly CT scan
Often normalOften normal
Why do?Why do? Exclude haemorrhageExclude haemorrhage Exclude tumourExclude tumour Grade for thrombolysis riskGrade for thrombolysis risk
Dense Middle Cerebral Dense Middle Cerebral ArteryArtery
Do early infarct signs Do early infarct signs matter?matter?
Help confirm diagnosisHelp confirm diagnosis
Dense middle cerebral arteryDense middle cerebral artery 10% chance opening with IV thromolysis10% chance opening with IV thromolysis ? May lead to intra-arterial or mechanical ? May lead to intra-arterial or mechanical
treatmentstreatments
Prognosis for thrombolysisPrognosis for thrombolysis 1/3 MCA territory1/3 MCA territory
ASPECTSASPECTS
Canadian studyCanadian study Academic CT head interpretationAcademic CT head interpretation Leads to 10 point scoring system on Leads to 10 point scoring system on
plain axial CT headplain axial CT head Scores of <7 increased functional Scores of <7 increased functional
dependence + increased risk of dependence + increased risk of deathdeath
ASPECTSASPECTS
Scored from two axial slicesScored from two axial slices One at thalamic level / basal gangliaOne at thalamic level / basal ganglia One just above ganglionic structures One just above ganglionic structures
(such that none are seen)(such that none are seen) 10 points 10 points
One subtracted for each area of early One subtracted for each area of early ischemic change (thus score 10=normal ischemic change (thus score 10=normal scan)scan)
Core messageCore message
Extensive early infarction may be Extensive early infarction may be poor prognostic indicator for poor prognostic indicator for outcome from thrombolysisoutcome from thrombolysis
Intracerebral Intracerebral HaemorrhageHaemorrhage
Main causesMain causes HypertensionHypertension Cerebral Amyloid Angiopathy (CAA)Cerebral Amyloid Angiopathy (CAA) RaritiesRarities
Hypertensive bleedHypertensive bleed
Cerebral Amyloid Cerebral Amyloid AngiopathyAngiopathy
Can be more subtleCan be more subtle
Core messageCore message
Main causes of intracerebral Main causes of intracerebral haemorrhage are amyloid haemorrhage are amyloid angiopathy and hypertensionangiopathy and hypertension
TumourTumour
Can be subtleCan be subtle History reviewHistory review
Non acute onsetNon acute onset SeizuresSeizures HeadacheHeadache CancerCancer
Plain CT may not showPlain CT may not show ContrastContrast
Subtle sub-acute LEFT Subtle sub-acute LEFT weaknessweakness
Post contrastPost contrast
Brain tumoursBrain tumours
Often contrast Often contrast enhance enhance
May have vasogenic May have vasogenic oedemaoedema
May respect grey / May respect grey / white junctionwhite junction
Other mimicsOther mimics
Subdural haematoma Subdural haematoma Sub arachnoid haemorrhageSub arachnoid haemorrhage
++++
Subdural haematoma Subdural haematoma
Sub arachnoid Sub arachnoid haemorrhagehaemorrhage
Don’t miss mimicsDon’t miss mimics
History just as important as the History just as important as the scan!scan!
Timing of CT changesTiming of CT changes
InfarctInfarct
HaemorrhageHaemorrhage
HaemorrhageHaemorrhage
Core messageCore message
After 10-14 days both haemorrhage After 10-14 days both haemorrhage and infarct both look like a black and infarct both look like a black holehole
Important to be able to distinguish Important to be able to distinguish old from new infarctsold from new infarcts
Urgent Scans Urgent Scans
% of URGENT scans performed % of URGENT scans performed within 60mins of arrival to hospital within 60mins of arrival to hospital (Best Prac + NICE quality standard)(Best Prac + NICE quality standard)
90% by April 201190% by April 2011 Best practice = scan + reportBest practice = scan + report
What are indications for What are indications for an urgent scan?an urgent scan?
GCS <13GCS <13 On WarfarinOn Warfarin Bleeding tendencyBleeding tendency Severe headacheSevere headache Papilloedema / neck stiff / feverPapilloedema / neck stiff / fever Progressive / fluctuating symptomsProgressive / fluctuating symptoms For thrombolysisFor thrombolysis
MRI scanMRI scan
Why do an MRI?Why do an MRI?
If stroke uncertainIf stroke uncertain To confirm vascular territoryTo confirm vascular territory Look for multi-territory involvementLook for multi-territory involvement
Look for previous haemorrhageLook for previous haemorrhage
Main MRI sequencesMain MRI sequencesDiffusionDiffusion
Main MRI sequencesMain MRI sequencesGradient-echo (T2*)Gradient-echo (T2*)
CT PerfusionCT Perfusion
Concept of ischaemic pemumbraConcept of ischaemic pemumbra
CT PerfusionCT Perfusion
Cerebral blood volumeCerebral blood volume Cerebral blood flowCerebral blood flow
MismatchMismatch
CT PerfusionCT Perfusion
Wake up strokesWake up strokes Large strokesLarge strokes Timing questionsTiming questions MimicsMimics
FutureFuture
More CT PerfusionMore CT Perfusion More MRIMore MRI Movement towards acute arterial Movement towards acute arterial
imagingimaging
SummarySummary
Brain imaging from Stroke Physician Brain imaging from Stroke Physician perspectiveperspective
Targets – why + howTargets – why + how Where imaging may goWhere imaging may go