acute stroke imaging and intervention-dr. n khandelwal

ACUTE STROKE: IMAGING AND INTERVENTIONS PERSPECTIVE

Dr. N KHANDELWALPROF AND HEAD

DEPARTMENT OF RADIODIAGNOSIS & IMAGINGPGIMER, Chandigarh

Aims of Imaging• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• To detect early signs of ischemia.• To detect the site of occlusion.• To take a treatment decision.• To prognosticate the patient.

• EVERYTHING TO BE DONE IN 10-15 MINUTES

Aims of Imaging

• To rule out intracranial hemorrhage.

– NCCT – MRI :FLAIR and gradient echo imaging.

Aims of Imaging

• To rule out intracranial hemorrhage.

Aims of Imaging

• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• Seizure• Mass lesion• Hypoglycemia• Migraine• Metabolic

encephalopathy• Multiple Sclerosis• Epidural/subdural

hematoma

Aims of Imaging

• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• To detect early signs of ischemia.

– Dense artery sign– Loss of gray-white differentiation

Dense Artery Sign

NCCT Head Evaluation

Loss of gray white interface


Loss of insular ribbon


Obscure lentiform nucleus


14 th JULY 11 PM

What we can do to increase the diagnostic confidence ?


Aims of Imaging

• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• To detect early signs of ischemia.• To detect the site of occlusion.

CT Angiography Evaluation

Advanced helical CT application.

High spatial resolution 3d images of the cervical and intracranial vasculature

Permits rapid identification of vessel stenosis/occlusion

• Helpful tip: if no definite occlusion……


Aims of Imaging

• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• To detect early signs of ischemia.• To detect the site of occlusion.• To take a treatment decision.• To prognosticate the patient.

Prognosticating the patient……

• NCCT based approach

• CT angiography based approach

Alberta Stroke Program Early CT Score (ASPECTS)

• Baseline ASPECTS correlated inversely with the NIHSS

• As the ASPECTS decreased, the probability of

dependence, death, and symptomatic hemorrhage increased

TOTAL SCORE =10

SUBTRACT THE NUMBER OF HYPODENSE REGIONS FROM THIS SCORE OF 10.

8-10= GOOD PROGNOSIS

<8= POOR PROGNOSIS

Alberta Stroke Program Early CT Score (ASPECTS)

SCORE : 10-2= 8- GOOD PROGNOSIS

10-5=5. POOR PROGNOSIS




– COLLATERALS IMAGING• SINGLE PHASE CTA• MULTIPHASE CTA

Role of CT Perfusion…

• Limited– wake up strokes– Out of window period strokes

• MR diffusion-perfusion –same status• To decide if treatment would be helpful or

not.

CT Perfusion Parameters

MTT:+++CBF: NormalCBV: Normal

MTT: +++CBF: DecreasedCBV: Normal

Treatment indicated

Treatment may be given

MTT: +++CBF: DecreasedCBV: Decreased Treatment might be

harmful

Aims of Imaging

• To rule out intracranial hemorrhage.• To rule out stroke mimickers.• To detect early signs of ischemia.• To detect the site of occlusion.• To take a treatment decision.

Site of Occlusion

Proximal

Distal

• ICA bifurcation• M1-MCA• MCA bifurcation• A1-ACA• Vertebral-Basilar

artery• P1-PCA

• M2-M4 MCA• A2-A4-ACA• P2-P4 PCA

Mechanical thrombectomy

Thrombolysis

INTERVENTIONS IN ACUTE STROKE

CHOICE OF INTERVENTIONS

– IV THROMBOLYSIS

– IA THROMBOLYSIS

– MECHANICAL THROMBECTOMY

– MECHANICAL ASPIRATION

• Intravenous Thrombolysis (t-PA)

– Treatment of choice in small vessel acute stroke

(<4.5hrs).

– Treatment of choice in large vessel stroke but in

combination with mechanical thrombectomy


iv thrombolysis work….

Why do we need alternative form of treatment ?


Limitations of iv-tPA

– Moderate to poor efficacy in large strokes

– Window period too short

– Risk of bleed


Available Techniques:

•Intra-arterial thrombolysis

•Mechanical clot removal– MERCI– PENUMBRA – STENTRIEVERS– DIRECT ASPIRATION


ESCAPEEXTEND-IASWIFT PRIME

MR-CLEAN

Mechanical Thrombectomy

Stent retrievers


Mechanical ThrombectomyINTERVENTIONS IN ACUTE STROKE

• Ability to restore blood flow immediately,

administer medical therapy and retrieve clot.

• Basically a dedicated, low profile retrievable stent

system which catches the clot and retrieves it.


67y/M

• Weakness over left side of the body• deviation of face towards left side• inability to speak• Duration 4hrs

• Known case of Type 2 DM since 20 years, on medication

Post procedure NCCT

60Y/F

CLINICAL DETAILS:

• Known hypertensive and DM on treatment.• c/o unresponsiveness at 8:20pm with left facial deviation.• h/o vomiting – 2episodes.

O/E:• E1V1M3 status with non reacting pupils ? Posterior

circulation stroke.• NCCT HEAD WITH CT ANGIO.• IV THROMBOLYSIS

Mr.VA; 26 M

• Left facial weakness and right lower limb paresis of 16 hours duration.

• Upper limb paresis 4hrs.

Follow up

• Patient improved in the DSA room.

• Discharge with mRS of 4

• Mechanical Thrombectomy leads to good

outcomes

• Limitation is still the time of intervention

• Puncture to reperfusion time should be

minimized


Disadvantages:

•Blind negotiation of the occluded segment.

•Distal migration of clot fragments

•Complication rate 3-5%.


• Direct Catheter Aspiration– Attractive concept– No handling of thrombus– Minimally invasive– No blind progression of microcatheter

• Problems:– Larger bore catheters usually too stiff– No dedicated systems


Turk AS, et al. J NeuroIntervent Surg 2014;0:1–5. doi:10.1136/neurintsurg-2014-011125



AHA GUIDELINES:

Towards end……

• NCCT– Rule out hemorrhage– Early signs of

ischemia– Prognostication

(ASPECTS scoring)

• CT angiography– Site of blockage– Collateral mapping

• CT Perfusion– Wake up strokes.

• INTERVENTIONS– iv t-PA– Stentrievers– Direct aspiration technique

Time is the key.NCCT and CT angiography mainstay of imaging.

November 11-13, 2016Venue: Lecture theatre complex, PGIMER, Chandigarh

In collaboration with Society of Breast Imaging (SBI), USA

Thank You

acute stroke imaging and intervention-dr. n khandelwal

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