Imaging of the 3 Ps in Stroke An introduction of stroke diagnostics for the non-neurologist

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1 A picture is worth 1000 words but what do they mean? Imaging of the 3 Ps in Stroke An introduction of stroke diagnostics for the non-neurologist Sharon Jaspers Thunder Bay Regional Health Sciences Centre Stroke Prevention Clinic Nurse Practitioner Northern Ontario School of Medicine Assistant Professor

2 Objectives Describe the variety of imaging modalities required for stroke diagnostics Discuss the rationale for imaging modalities utilized in stroke diagnostics

3 Presenter Disclosure Grants/Research Support: Northern Ontario Academic Medicine Association (NOAMA) Clinical Innovation Fund - Co-Investigator for: The Incidence of Carotid Artery Disease in Northwestern Ontario New Evidence Based Toolkit for Triaging TIA & Mild Non-Disabling Stroke in Northwestern DOC Utility Research Study- Research Support Navigate Trial - Co-Investigator Other: Writing Committee Member of the 2014 & 2017 Canadian Stroke Best Practice Recommendations

4 Disclosure cont m-health Solutions and Icentia Services have provided an in-kind contribution of ambulatory cardiac monitors and will be discussed in this simulation. The reason we are using these products, is because they are used in the Stroke Prevention at Thunder Bay Regional Health Sciences Centre. Mitigating Potential Bias Discussion on ambulatory cardiac monitors will include the demonstrated products available at this workshop in addition to other options available in Northwestern Ontario.

5 Disclosure of Commercial Support This program has received product demos from m-health Solutions and Icentia Services to demonstrate options for ambulatory cardiac monitors and will be discussed in this program

6 Mitigating Potential Bias Discussion on ambulatory cardiac monitors will include the demonstrated products available at this workshop in addition to other options available in Northwestern Ontario Remainder of disclosures do not pertain to this presentation

7 What Diagnostic Test do you think is most valuable for diagnosing stroke? 1. CT head 2. MRI head 3. CTA head/neck 4. MRA head/neck

8 The Embrace Trial recommends 1. Prolonged cardiac monitoring to assess for presence of atrial fibrillation 2. Epley Maneouvre to reduce stroke risk 3. Sequential CT testing to determine stroke penumbra progress 4. Hugs for good health

9 Common Cause of Stroke is: 1. Atrial Fibrillation/Flutter 2. Carbon monoxide poisoning 3. Alzheimer's Disease 4. Omega 3 Fatty Acid Exposure

10 Our brains are incredibly complex Image copyright of FRONTIER Frontotemporal Dementia Research Group, n-dominance1.png.

11 ..unless you are Homer Images from

12 Imaging and the 3 Ps Parenchyma Pipes Pump

13 Parenchyma:The functional aspects of the Human Brain 100 billion nerve cells (neurons) All in grey matter Highly organized into functional regions Prolonged processes of the neuron (axons) surrounded by myelin (insulation) White matter

14 ahukewjqj5ay2qxaahvq5omkhsaxbygq_auicigb&biw=1040&bih=878#imgrc=gxnegccrxqbdpm

15 Albers et al. Chest 2004; 126 (3 Suppl): 438S 512S. Thom T, et al. Circulation 2006; 113(6): e85 e151.

16 Parenchyma Assessment: CT scan CT scans use computers and rotating X-ray machines to create images of slices, or crosssections, of the brain. CT scans are a primary method to rule out hemorrhagic stroke or tumor. Ischemic stroke is not usually apparent until 6 12 hrs from symptom onset Often the first diagnostic test when a pt presents to the ED determine if candidate for tpa In many cases, the involved area of the brain does not appear abnormal for the first several hours after the onset of ischemic stroke.

17 CT scan Rapid, cheap, well tolerated, but poor visualization of brain stem and posterior fossa Xrays are absorbed by different degrees by different tissues The colour is the result of how much radiation is absorbed (attenuation) air CSF White matter Old Blood Gray Matter Acute blood Bone Contrast Edema Calcifications Hypodense Hyperdense

Right side CT Head Left Side http://www.radiologyassistant.

18 Right side CT Head Left Side

CT hemorrhage CT CT brain stem infarct http://www.google.ca/imgres?imgurl=http://www.pssjournal.

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19 CT hemorrhage CT CT brain stem infarct 4.jpg&imgrefurl= NFNqd6Ho17sjdhdzzDvjvxgBhos=&h=320&w=310&sz=24&hl=en&start=26&zoom=1&tbnid=YfErDQ7qySeMMM: &tbnh=118&tbnw=114&ei=0kptunexdoecyagii4hoaw&prev=/search%3fq%3dct%2bbrain%2bstem%2binfarct%26start%3d20%26um%3d1%26hl%3den%26safe%3dactive%26sa%3dn%26rls %3Dcom.microsoft:en-us%26tbm%3Disch&um=1&itbs=1

20 Parenchymal Assessment: MRI Middle Cerebral artery Frontal lobe Corpus callosum Lateral ventricle Anterior Cerebral artery Corona radiata Parietal lobe Occipital lobe radiology.med.sc.edu/neuro%20no%20audio.ppt

Parenchyma Assessment: MRI Works by sending bursts of radio waves to head (MAGNETS) Waves disrupt protons (water containing) Once waves stop, protons relax, realign and picture is produced

21 Parenchyma Assessment: MRI Works by sending bursts of radio waves to head (MAGNETS) Waves disrupt protons (water containing) Once waves stop, protons relax, realign and picture is produced T1-2/Flair/DWI variations of protons (tissue) relaxation times Can visualize in various modes. DWI (diffusion weighted imaging) lets you know if it is a fresh/acute stroke Not as precise for hemorrhage Called intensity vs density More sensitive for acute ischemia Can pick up ischemic stroke sooner than CT in hyper acute stage.. More expensive/time than CT MRI axial FLAIR images of Brain show an infarct involving left frontal lobe anterior to sylvian fissure. Area of involvement corresponds to left MCA

22 MRI : ACUTE ISCHEMIC STROKE T1 (hypo intense) CSF is black White matter is white Shows anatomy better T2 (hyper intense) CSF is white White Matter is black Shows pathology better Diffusion (hyper intense) FLAIR (hyper intense) Acute infarcts are white due to edema Shows acute infarct better Infarcts are white due to intracellular edema radiology.med.sc.edu/neuro%20no%20audio.ppt

Parenchyma Assessment: MRI-Diffusion weighted image (DWI) is the MOST sensitive sequence Can be positive within minutes of stroke Produces a high

23 Parenchyma Assessment: MRI-Diffusion weighted image (DWI) is the MOST sensitive sequence Can be positive within minutes of stroke Produces a high intensity signal for 7 days, then settles Maximizes b/w 7 30 days (positive in early stage, then fades) radiology.med.sc.edu/neuro%20no%20audio.ppt

24 MRI contraindications Metallic implants Claustrophobia Pacemakers MR-incompatible prosthetic heart valves Patient Prep: Length, noise- ear plugs, no jewelery,

25 Albers et al. Chest 2004; 126 (3 Suppl): 438S 512S. Thom T, et al. Circulation 2006; 113(6): e85 e151.

26 Pipes Assessment: Vascular Imaging CTA MRA Carotid Doppler Cerebral angiography Purpose is to assess for atherosclerosis, thrombosis or aneurysm

27 Pipes Assessment: Vascular Imaging Diagnostic Test Benefit Limitations CTA -Assessing degree of stenosis of carotid arteries -visualizing vessel character -guides treatment -accuracy -require adequate kidney function to tolerate dye -precautions when on metformin - MRA -Assessing degree of stenosis -no dye involved that impacts kidneys -neurosurgeons prefer CTA Carotid Doppler Cerebral Angiography -Assessing degree of stenosis with less invasive approach -precise, finite imaging Can be used singularly or in conjunction with other treatment eg: clot retrieval -not as accurate --requires interventional radiologist/neurosurgeon -most invasive -more risks/inconvenience for patient

29 3D CTA reconstruction of left MCA total occlusion 3D CTA reconstruction image of the carotid arteries showing a stent in right internal carotid and a 99% stenosis or blockage of the left ICA hotocat/gallery3.cfm%3fimage%3d3dreccarotidctastnt.jpg%26pg%3dangioct&usg=

http://jnnp.bmj.com/content/76/suppl_3/iii19/f9.large.

30 CTA (on left ) right middle cerebral artery stenosis (below) a)basilar artery stenosi b) total left internal carotid occlusion c) left internal carotid stenosis d)right internal carotid stenosis

31 Albers et al. Chest 2004; 126 (3 Suppl): 438S 512S. Thom T, et al. Circulation 2006; 113(6): e85 e151.

PUMP 20-30% of ischemic strokes are related to emboli from heart, can cause significant strokes with major deficits large vessels involved ie AF,

32 PUMP 20-30% of ischemic strokes are related to emboli from heart, can cause significant strokes with major deficits large vessels involved ie AF, PFO, ASD, myoxma, endocarditis, valve disease, recent MI, dilated cardiomyopathy, rheumatic stenosis, ttp://

33 PUMP: Echocardiogram Test that uses sound waves to create a moving picture of heart, assessing valves/structures/presence of clots/thrombi TTE Trans-thoracic echo TEE Trans-esophageal Echo Transducer on chest wall Bubble study: saline solution (salt water) is injected into the body as the cardiologist watches the heart on an ultrasound (echocardiogram) monitor. If a PFO exists, tiny air bubbles will be seen moving from the right to left side of the heart. Transducer/scope inserted in esophagus Better imaging in certain circumstances ie PFO

34 PUMP: Cardiac Rhythm Monitoring Manual pulse rhythm gives clue for possible A-fib ECG Telemetry Holter hours Loop Recorder x 2 weeks Focus is to rule out atrial fibrillation/flutter or paroxysmal A-Fib A-Fib most common cause of cardio-embolic stroke why???? Risk for A-Fib induced stroke increases with age 1.5% risk at age 50 and 24% risk at age 80

35 Summary of 3 Ps Stroke Diagnostic Tests 1. Parenchyma (CT/MRI) Help determine character of lesion and pathology 2. Pipes (Carotid Doppler, CTA, MRA) Help to determine possible etiology of stroke 3. Pump (Echocardiogram, cardiac monitoring) Help to determine possible etiology of stroke

36 What Diagnostic Test do you think is most valuable for diagnosing stroke? 1. CT head 2. MRI head 3. CTA head/neck 4. MRA head/neck

37 The Embrace Trial recommends 1. Prolonged cardiac monitoring to assess for presence of atrial fibrillation 2. Epley Maneouvre to reduce stroke risk 3. Sequential CT testing to determine stroke penumbra progress 4. Hugs for good health

38 Common Cause of Stroke is: 1. Atrial Fibrillation/Flutter 2. Carbon monoxide poisoning 3. Alzheimer's Disease 4. Omega 3 Fatty Acid Exposure

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40 Questions & Discussion

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