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CC BY-NC-ND 4.0 · Ann Natl Acad Med Sci 2019; 55(04): 193-201
DOI: 10.1055/s-0040-1701321
Review Article

Acute Stroke Imaging: Current Trends

Chirag Kamal Ahuja
1   Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research, Chandigarh, Punjab, India
,
Vivek Gupta
2   Department of Interventional Neuroradiology, Paras Hospital, Panchkula, Haryana, India
,
Niranjan Khandelwal
1   Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research, Chandigarh, Punjab, India
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Abstract

The management of acute ischemic stroke has witnessed a paradigm change in the last few years with the advent of mechanical thrombectomy. Imaging plays a key role in evaluation and patient selection. Computed tomography (CT) forms the workhorse in most centers due to its widespread availability and quick performance, though magnetic resonance imaging (MRI) can also be adopted as a reasonable alternative. The key role of imaging is to rule out hemorrhage and other stroke mimics while at the same time establish early signs of ischemia and provide detailed information of cervicocranial vasculature and salvageable brain parenchyma; all in the shortest timeframe. Key imaging predictors of good clinical outcomes are good Alberta stroke protocol early CT score (ASPECTS) (greater than 6) and collateral scores. Selection of patients beyond the standard window period of 6 to 8 hours has become possible by tissue perfusion imaging with some recent trials demonstrating the utility of thrombectomy even up to 24 hours. Quick MRI-based protocols are being devised to achieve similar information as on CT with no adverse effects related to radiation and contrast effects. Research is underway to decipher the intricacies of blood flow in the brain through more sophisticated imaging methods in attempt to increase the base for mechanical thrombectomy, which will benefit more number of patients.

Keywords

ischemic stroke - mechanical thrombectomy - computed tomography - MRI - cervicocranial vasculature - salvage brain parenchyma


Publication History

Article published online:
12 February 2020

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  • References

  • 1 National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 1995; 333: 1581-1587
    CrossrefPubMedGoogle Scholar
  • 2 Goyal M, Demchuk AM, Menon BK. et al; ESCAPE Trial Investigators. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med 2015; 372 (11) 1019-1030
    CrossrefPubMedGoogle Scholar
  • 3 Emberson J, Lees KR, Lyden P. et al; Stroke Thrombolysis Trialists’ Collaborative Group. Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials. Lancet 2014; 384 (9958): 1929-1935
    CrossrefPubMedGoogle Scholar
  • 4 Saver JL. Time is brain–quantified. Stroke 2006; 37 (01) 263-266
    CrossrefPubMedGoogle Scholar
  • 5 Goyal M, Jadhav AP, Bonafe A. et al. SWIFT PRIME investigators. Analysis of workflow and time to treatment and the effects on outcome in endovascular treatment of acute ischemic stroke: results from the SWIFT PRIME randomized controlled trial. Radiology 2016; 279 (03) 888-897
    CrossrefPubMedGoogle Scholar
  • 6 Menon BK, Almekhlafi MA, Pereira VM. et al. STAR Study Investigators. Optimal workflow and process-based performance measures for endovascular therapy in acute ischemic stroke: analysis of the Solitaire FR thrombectomy for acute revascularization study. Stroke 2014; 45 (07) 2024-2029
    CrossrefPubMedGoogle Scholar
  • 7 Siesjö BK. Pathophysiology and treatment of focal cerebral ischemia. Part II: mechanisms of damage and treatment. J Neurosurg 1992; 77 (03) 337-354
    CrossrefPubMedGoogle Scholar
  • 8 Weinstein PR, Hong S, Sharp FR. Molecular identification of the ischemic penumbra. Stroke 2004; 35 (11) (Suppl. 01) 2666-2670
    CrossrefPubMedGoogle Scholar
  • 9 Smith AG, Rowland Hill C. Imaging assessment of acute ischaemic stroke: a review of radiological methods. Br J Radiol 2018; 91 (1083) 20170573
    PubMedGoogle Scholar
  • 10 Na DG, Kim EY, Ryoo JW. et al. CT sign of brain swelling without concomitant parenchymal hypoattenuation: comparison with diffusion- and perfusion-weighted MR imaging. Radiology 2005; 235 (03) 992-48
    CrossrefPubMedGoogle Scholar
  • 11 Riedel CH, Zoubie J, Ulmer S, Gierthmuehlen J, Jansen O. Thin-slice reconstructions of nonenhanced CT images allow for detection of thrombus in acute stroke. Stroke 2012; 43 (09) 2319-2323
    CrossrefPubMedGoogle Scholar
  • 12 Srinivasan A, Goyal M, Al Azri F, Lum C. State-of-the-art imaging of acute stroke. Radiographics 2006; 26 (Suppl. 01) S75-S95
    CrossrefPubMedGoogle Scholar
  • 13 Patel SC, Levine SR, Tilley BC. et al. National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Lack of clinical significance of early ischemic changes on computed tomography in acute stroke. JAMA 2001; 286 (22) 2830-2838
    CrossrefPubMedGoogle Scholar
  • 14 Barber PA, Demchuk AM, Zhang J, Buchan AM. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet 2000; 355 (9216) 1670-1674
    CrossrefPubMedGoogle Scholar
  • 15 Jovin TG, Chamorro A, Cobo E. et al; REVASCAT Trial Investigators. Thrombectomy within 8 hours after symptom onset in ischemic stroke. N Engl J Med 2015; 372 (24) 2296-2306
    CrossrefPubMedGoogle Scholar
  • 16 Wintermark M, Rowley HA, Lev MH. Acute stroke triage to intravenous thrombolysis and other therapies with advanced CT or MR imaging: pro CT. Radiology 2009; 251 (03) 619-626
    CrossrefPubMedGoogle Scholar
  • 17 Menon BK, Goyal M. Imaging paradigms in acute ischemic stroke: a pragmatic evidence-based approach. Radiology 2015; 277 (01) 7-12
    CrossrefPubMedGoogle Scholar
  • 18 Elijovich L, Goyal N, Mainali S. et al. CTA collateral score predicts infarct volume and clinical outcome after endovascular therapy for acute ischemic stroke: a retrospective chart review. J Neurointerv Surg 2016; 8 (06) 559-562
    CrossrefPubMedGoogle Scholar
  • 19 Menon BK, d’Esterre CD, Qazi EM. et al. Multiphase CT angiography: a new tool for the imaging triage of patients with acute ischemic stroke. Radiology 2015; 275 (02) 510-520
    CrossrefPubMedGoogle Scholar
  • 20 Riedel CH, Zimmermann P, Jensen-Kondering U, Stingele R, Deuschl G, Jansen O. The importance of size: successful recanalization by intravenous thrombolysis in acute anterior stroke depends on thrombus length. Stroke 2011; 42 (06) 1775-1777
    CrossrefPubMedGoogle Scholar
  • 21 Nogueira RG, Jadhav AP, Haussen DC. et al; DAWN Trial Investigators. Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct. N Engl J Med 2018; 378 (01) 11-21
    CrossrefPubMedGoogle Scholar
  • 22 Albers GW, Marks MP, Kemp S. et al. DEFUSE 3 Investigators. DEFUSE 3 Investigators. Thrombectomy for stroke at 6 to 16 hours with selection by perfusion imaging. N Engl J Med 2018; 378 (08) 708-718
    CrossrefPubMedGoogle Scholar
  • 23 Konstas AA, Goldmakher GV, Lee TY, Lev MH. Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 1: theoretic basis. Am J Neuroradiol 2009; 30 (04) 662-668
    CrossrefPubMedGoogle Scholar
  • 24 Kidwell CS, Alger JR, Saver JL. Beyond mismatch: evolving paradigms in imaging the ischemic penumbra with multimodal magnetic resonance imaging. Stroke 2003; 34 (11) 2729-2735
    CrossrefPubMedGoogle Scholar
  • 25 Aviv RI, d’Esterre CD, Murphy BD. et al. Hemorrhagic transformation of ischemic stroke: prediction with CT perfusion. Radiology 2009; 250 (03) 867-877
    CrossrefPubMedGoogle Scholar
  • 26 Austein F, Riedel C, Kerby T. et al. Comparison of perfusion CT software to predict the final infarct volume after thrombectomy. Stroke 2016; 47 (09) 2311-2317
    CrossrefPubMedGoogle Scholar
  • 27 Nael K, Khan R, Choudhary G. et al. Six-minute magnetic resonance imaging protocol for evaluation of acute ischemic stroke: pushing the boundaries. Stroke 2014; 45 (07) 1985-1991
    CrossrefPubMedGoogle Scholar
  • 28 Hjort N, Christensen S, Sølling C. et al. Ischemic injury detected by diffusion imaging 11 minutes after stroke. Ann Neurol 2005; 58 (03) 462-465
    CrossrefPubMedGoogle Scholar
  • 29 Luby M, Warach SJ, Nadareishvili Z, Merino JG. Immediate changes in stroke lesion volumes post thrombolysis predict clinical outcome. Stroke 2014; 45 (11) 3275-3279
    CrossrefPubMedGoogle Scholar
  • 30 Yoo AJ, Verduzco LA, Schaefer PW, Hirsch JA, Rabinov JD, González RG. MRI-based selection for intra-arterial stroke therapy: value of pretreatment diffusion-weighted imaging lesion volume in selecting patients with acute stroke who will benefit from early recanalization. Stroke 2009; 40 (06) 2046-2054
    CrossrefPubMedGoogle Scholar
  • 31 Parsons MW, Christensen S, McElduff P. et al; Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) Investigators. Pretreatment diffusion- and perfusion-MR lesion volumes have a crucial influence on clinical response to stroke thrombolysis. J Cereb Blood Flow Metab 2010; 30 (06) 1214-1225
    Google Scholar
  • 32 Singer OC, Berkefeld J, Lorenz MW. et al. MR Stroke Study Group Investigators. Risk of symptomatic intracerebral hemorrhage in patients treated with intra-arterial thrombolysis. Cerebrovasc Dis 2009; 27 (04) 368-374
    CrossrefPubMedGoogle Scholar
  • 33 Kim JH, Bang OY, Liebeskind DS. et al; UCLA-Samsung Stroke Collaborators. Impact of baseline tissue status (diffusion-weighted imaging lesion) versus perfusion status (severity of hypoperfusion) on hemorrhagic transformation. Stroke 2010; 41 (03) e135-e142
    CrossrefPubMedGoogle Scholar
  • 34 Bash S, Villablanca JP, Jahan R. et al. Intracranial vascular stenosis and occlusive disease: evaluation with CT angiography, MR angiography, and digital subtraction angiography. AJNR Am J Neuroradiol 2005; 26 (05) 1012-1021
    PubMedGoogle Scholar
  • 35 Gillard JH, Oliverio PJ, Barker PB, Oppenheimer SM, Bryan RN. MR angiography in acute cerebral ischemia of the anterior circulation: a preliminary report. AJNR Am J Neuroradiol 1997; 18 (02) 343-350
    PubMedGoogle Scholar
  • 36 Bivard A, Krishnamurthy V, Stanwell P. et al. Arterial spin labeling versus bolus-tracking perfusion in hyperacute stroke. Stroke 2014; 45 (01) 127-133
    CrossrefPubMedGoogle Scholar
  • 37 Kidwell CS, Chalela JA, Saver JL. et al. Comparison of MRI and CT for detection of acute intracerebral hemorrhage. JAMA 2004; 292 (15) 1823-1830
    CrossrefPubMedGoogle Scholar
  • 38 Thomalla G, Rossbach P, Rosenkranz M. et al. Negative fluid-attenuated inversion recovery imaging identifies acute ischemic stroke at 3 hours or less. Ann Neurol 2009; 65 (06) 724-732
    CrossrefPubMedGoogle Scholar
  • 39 Kufner A, Galinovic I, Brunecker P. et al. Early infarct FLAIR hyperintensity is associated with increased hemorrhagic transformation after thrombolysis. Eur J Neurol 2013; 20 (02) 281-285
    CrossrefPubMedGoogle Scholar
  • 40 Smith EE, Fonarow GC, Reeves MJ. et al. Outcomes in mild or rapidly improving stroke not treated with intravenous recombinant tissue-type plasminogen activator: findings from Get With The Guidelines-Stroke. Stroke 2011; 42 (11) 3110-3115
    CrossrefPubMedGoogle Scholar