Stroke Imaging. Discussion in Picture Form (mostly) Jeremy Hopkin M.D Neuroradiology lead IHC

Transcription

1 Stroke Imaging Discussion in Picture Form (mostly) Jeremy Hopkin M.D Neuroradiology lead IHC

2 Goals Lots of pictures little text Limit use of technical jargon Historical neuro imaging - biased to stroke Review current modalities and strength/weakness IHC approach to stroke imaging Have some fun (hopefully) End early

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5 Skull x rays

6 Ventriculostomy air contrast

7 Pneumoencephalography air contrast

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12 oldendorf Even if it could be made to work as you suggest, we cannot imagine a significant market for such an expensive apparatus which would do nothing but make a radiographic cross-section of a head.

13 First CT Hounsfield

14 Contrast - CTA

15 Contrast - CTP

16 MRI

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21 Modalities for further discussion: -CT -CTA -CTP -MRI Focus on ischemic stroke but at least touch on hemorrhagic

22 CT hemorrhagic stroke

23 Blood or Calcification?

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25 CT -Ischemic stroke 4 hours

26 CT 3.5 hours

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29 CT - hemorrhage

30 CT subacute/chronic fogging

31 CT - chronic

32 CT accuracy?

33 CT - Dense MCA

34 CTA hemorrhagic stroke

35 CTA ischemic stroke

36 CTA ischemia Source images

37 CTA multi phase collateral

38 CTP ischemic stroke

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41 Inherent limitations of technique: Flow Hematocrit Oxygen extraction Chronicity of ischemia Metabolic demands of tissue Temperature Genetics Quick understanding of market potential by vendors Development of multiple systems in collateral Usually proprietary methods End is fairly dissimilar products trying to be utilized for the same goal Extensive and confusing literature If A=B, and B=C and C=D does A=D? They are often compared to one another or another surrogate marker for stroke but are not consistently compared to DWI

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43 CTP - RAPID

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45 CTP bottom line CORRELATES with final infarct volume Wide variability between techniques/software Some software packages seem to be more precision (RAPID) CANNOT accurately depict final infarct volume Does it matter? Is correlation good enough for patient selection?

46 MRI hemorrhagic stroke

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49 MRI ischemic stroke DWI Sensitivity/Specificity 95+ % Volume accuracy typically within 5 cc Ranges from 0-20cc

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52 Advanced techniques - Summary

53 What we know - imaging MRI Best non invasive evaluation of infarct core Slightly more sensitive for blood than CT Still relatively slow CT Great for detecting blood Not great for core fast CTA Great for detecting occlusion CTA SI moderate for detecting core Fast CTP Moderate for detecting infarct core Pretty fast RAPID software is likely most precise and is fast

54 Approach to acute stroke imaging Be fast Triage, access to equipment and transport Streamline and standardize imaging towards speed Open and standardized communication pathways Be accurate Use best evidence to standardize image acquisition, post process and display Repetitive/Constant peer review Be reproducible Standardized reporting Be open to innovation and flexible to incorporate new data System approach lends itself to constant review of data and agility to respond quickly

55 IHC approach (in evolution) CT (Service process model complete) ASPECTS score report Communication (documented) CTA (Service process model in process) Performed for all stroke cases (ischemic/hemorrhagic) Used at all centers seeing acute stroke patients with capability Used liberally to screen for LVO with stroke symptoms CTA SI ASPECTS score report Communication of LVO (documented) CTP (Service process model in process) Deployed selectively (typically at endovascular centers) RAPID software at endovascuar centers MRI (not developed) Use liberally for stroke mimics, difficult cases or standard acute cases if available Standardize rapid stroke protocols

56 How do we get this done? NSCP Guidance council for all things neuro Neuro lead takes information from NSCP to inform SPM process development ISMC Guidance council for radiology Voting control from each group single representative SPM presented and voted upon Incentive/punitive for SPM use SPM subject to yearly review at minimum

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59 Lessons from the past Potentially obsolete or underutilized technology may resurface sometimes in unexpected ways Need for advanced imaging is almost always underestimated Slow becomes fast Less accurate becomes more accurate FUTURE - Move from anatomic towards physiologic/metabolic imaging fused with anatomy

60 Future directions stroke (Opinion) More MRI. Speed? Screening? Got to make this fast. How is this not one of the first things on an EMR? More MRI compatible devices More MRI with non compatible devices Culture. Speed over quality. Historically this has been used in a non emergent setting. CT techs and MRI techs don t think the same. Barrow experience Physiologic/metabolic imaging. O2 imaging? Better outcomes with improved risk stratification and selection CT advances Dual energy for thrombus morphology? Dual energy and core detection? New perfusion techniques?? New technology from endovascular or diagnostic side

61 M2 occlusion Do you treat?

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63 Goals Lots of pictures little text Limit use of technical jargon Historical neuro imaging - biased to stroke Review current modalities and strength/weakness IHC approach to stroke imaging Have some fun (hopefully) End early