Place for Interventional Radiology in Acute Stroke Dr Lakmalie Paranahewa MBBS, MD(Radiology), FRCR Consultant Interventional Radiologist Asiri Group of Hospitals
Objectives Imaging in Stroke Neurovascular Interventions in Stroke
Imaging in stroke Goal of Imaging Confirm diagnosis and rule out haemorrhage Exclude mimics Differentiate between Irreversible and Reversible damage (dead vs at risk) Identify cause and location (intra and extracranial vessel occlusion) To plan appropriate therapy and predict outcome
Imaging in stroke Imaging Modalities available CT MRI DSA
Imaging in stroke CT SCAN Readily available Better tolerated by sick patients Acceptable imaging time Exclude haemorrhage (gold standard)
Imaging in stroke CT Differentiate SCAN early between signs irreversibly affected Irreversible brain tissue and reversibly impaired tissue (dead tissue versus tissue at risk) Identify stenosis or occlusion of major extra- and intracranial arteries Dense MCA sign Sylvian Dot sign Insular Ribbon Hypo sign attenuation of brain tissue Obscured Sulcal lentiform effacement nucleus
Imaging in stroke CT Angiogram To asses intra and extra cranial vasculature Plan further management
CT Angiogram Imaging in stroke
Imaging in stroke CT Perfusion To detect volume of tissue at risk Monitor the first pass of an iodinated contrast bolus through the cerebral vasculature.
Imaging in stroke CT Perfusion Study - Parameters CBV - Volume of blood per unit of brain tissue CBF - Volume of blood flow per unit of brain tissue per minute MTT - Time difference between arterial inflow and venous outflow. TTP - Time from injection to max. conc in ROI.
Imaging in stroke CT Perfusion Study - Parameters CT perfusion scan of the head demonstrates findings consistent with large ischemic penumbra. Decreased cerebral blood flow Preserved cerebral blood volume Prolonged time to peak and mean transit time in the left middle cerebral and bilateral anterior cerebral artery distributions
Imaging in stroke CT Perfusion Study Penumbra
MRI SCAN Imaging in stroke Early visible changes More sensitive and specific than CT But Better evaluation of stroke mimics Relatively less available Long scanning times
MRI SCAN Imaging in stroke High T2 and Flair signal - irreversible 2-24 hours from onset
Imaging in stroke MRI SCAN Diffusion Weighted Imaging Most sensitive sequence for stroke imaging.
MRI SCAN DWI Imaging in stroke
MRI SCAN DWI Imaging in stroke
Imaging in stroke MRI SCAN Perfusion Imaging Comparable to CT perfusion imaging
Imaging in stroke Digital Subtraction Angiography Gold standard in vascular imaging To confirm CTA / MRA findings Mainly when endovascular management is planned DSA
Neurovascular intervention in stroke Intrarterial thrombolysis To expand the time window Rapid local delivery of thrombolytic agent through a micro catheter placed at the site of occlusion (1-2 hour infusion) Increased recanalization rates (esp in major vessel occlusion) Reduced haemorrhagic complications (low dose) DSA
Neurovascular intervention in stroke Combined Intrvenous /arterial thrombolysis To combine the advantages of both techniques IV fast + easy IA Direct therapy, Titrated dose Increases recanalization rates Combined Bridging Technique Increased recanalisation rates Better functional outcome at 3 months
Neurovascular intervention in stroke Endovascular Thrombectomy Mercy device Solitare Catch device Vasco35 Neuronet device Phenox Clot Retriever Alligator Retrieval Device
Neurovascular intervention in stroke Thromboaspiration following stent placement Solitare stent Very high recanalisation rates
Neurovascular intervention in stroke
Neurovascular intervention in stroke Thromboaspiration following stent placement
# 1
Time at procedure 4 ½ hours
# 2
Time at procedure 6 hours
# 3
Time at procedure? 12 hours
Neurovascular intervention Conclusion in stroke Primary determinant of successful outcome is Time.
Thank you