Brain Ischemia: CT and MRI Techniques in Acute Stroke

  • Howard A. RowleyEmail author
  • Pedro Vilela


The past year has seen rapid advances in acute stroke therapy based on advanced imaging selection [1–5]. The main aim of imaging in acute ischemic stroke (AIS) is to rule out hemorrhage and stroke mimics, to define the extension of established infarct (core), and to identify the occlusion site, which are the main factors involved in the acute treatment decision: conservative, IV thrombolysis, and mechanical thrombectomy [1–5]. Additional relevant information includes the extension of the core (or penumbra), the type and length of the clot, and the individual collateral circulation that may allow the individual AIS treatment strategies.


Stroke Thrombolysis Computed tomography Magnetic resonance imaging 



The authors acknowledge the contribution of Prof Dr Jens Fiehler for his generous contributions to the manuscript, figures, and concepts.


  1. 1.
    Berkhemer OA, Fransen PSS, Beumer D, van den Berg LA, Lingsma HF, Yoo AJ et al (2015) A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med 372(1):11–20CrossRefPubMedGoogle Scholar
  2. 2.
    Saver JL, Goyal M, Bonafe A, Diener H-C, Levy EI, Pereira VM et al (2015) Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med 372(24):2285–2295CrossRefPubMedGoogle Scholar
  3. 3.
    Jovin TG, Chamorro A, Cobo E, de Miquel MA, Molina CA, Rovira A et al (2015) Thrombectomy within 8 hours after symptom onset in ischemic stroke. N Engl J Med 372(24):2296–2306CrossRefPubMedGoogle Scholar
  4. 4.
    Goyal M, Demchuk AM, Menon BK, Eesa M, Rempel JL, Thornton J et al (2015) Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med 372(11):1019–1030CrossRefPubMedGoogle Scholar
  5. 5.
    Campbell BCV, Mitchell PJ, Kleinig TJ, Dewey HM, Churilov L, Yassi N et al (2015) Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med 372(11):1009–1018CrossRefPubMedGoogle Scholar
  6. 6.
    Muir KW, Buchan A, von Kummer R, Röther J, Baron J-C (2006) Imaging of acute stroke. Lancet Neurol 5(9):755–768CrossRefPubMedGoogle Scholar
  7. 7.
    Wintermark M, Rowley HA, Lev MH (2009) Acute stroke triage to intravenous thrombolysis and other therapies with advanced CT or MR imaging: pro CT. Radiology 251(3):619–626CrossRefPubMedGoogle Scholar
  8. 8.
    Köhrmann M, Schellinger PD (2009) Acute stroke triage to intravenous thrombolysis and other therapies with advanced CT or MR imaging: pro MR imaging. Radiology 251(3):627–633CrossRefPubMedGoogle Scholar
  9. 9.
    Saver JL (2006) Time is brain--quantified. Stroke 37(1):263–266CrossRefPubMedGoogle Scholar
  10. 10.
    Jauch EC, Saver JL, Adams HP, Bruno A, Connors JJB, Demaerschalk BM et al (2013) Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 44:870–947CrossRefPubMedGoogle Scholar
  11. 11.
    Rowley HA (2013) The alphabet of imaging in acute stroke: does it spell improved selection and outcome? Stroke 44(6 Suppl 1):S53–S54CrossRefPubMedGoogle Scholar
  12. 12.
    Salottolo KM, Fanale CV, Leonard KA, Frei DF, Bar-Or D (2011) Multimodal imaging does not delay intravenous thrombolytic therapy in acute stroke. Am J Neuroradiol 32(5):864–868CrossRefPubMedGoogle Scholar
  13. 13.
    Latchaw RE, Alberts MJ, Lev MH, Connors JJ, Harbaugh RE, Higashida RT et al (2009) Recommendations for imaging of acute ischemic stroke: a scientific statement from the American Heart Association. Stroke 40(11):3646–3678CrossRefPubMedGoogle Scholar
  14. 14.
    Hill MD, Rowley HA, Adler F, Eliasziw M, Furlan A, Higashida RT et al (2003) Selection of acute ischemic stroke patients for intra-arterial thrombolysis with pro-urokinase by using ASPECTS. Stroke 34(8):1925–1931CrossRefPubMedGoogle Scholar
  15. 15.
    Puetz V, Sylaja PN, Coutts SB, Hill MD, Dzialowski I, Mueller P et al (2008) Extent of hypoattenuation on CT angiography source images predicts functional outcome in patients with basilar artery occlusion. Stroke 39(9):2485–2490CrossRefPubMedGoogle Scholar
  16. 16.
    Puetz V, Khomenko A, Hill MD, Dzialowski I, Michel P, Weimar C et al (2011) Extent of hypoattenuation on CT angiography source images in basilar artery occlusion: prognostic value in the Basilar Artery International Cooperation Study. Stroke 42(12):3454–3459CrossRefPubMedGoogle Scholar
  17. 17.
    Kimura K, Sakamoto Y, Aoki J, Iguchi Y, Shibazaki K, Inoue T (2011) Clinical and MRI predictors of no early recanalization within 1 hour after tissue-type plasminogen activator administration. Stroke 42(11):3150–3155CrossRefPubMedGoogle Scholar
  18. 18.
    Riedel CH, Zimmermann P, Jensen-Kondering U, Stingele R, Deuschl G, Jansen O (2011) The importance of size: successful recanalization by intravenous thrombolysis in acute anterior stroke depends on thrombus length. Stroke 42(6):1775–1777CrossRefPubMedGoogle Scholar
  19. 19.
    Lansberg MG, Straka M, Kemp S, Mlynash M, Wechsler LR, Jovin TG et al (2012) MRI profile and response to endovascular reperfusion after stroke (DEFUSE 2): a prospective cohort study. Lancet Neurol 11(10):860–867CrossRefPubMedPubMedCentralGoogle Scholar
  20. 20.
    Dani KA, Thomas RGR, Chappell FM, Shuler K, Muir KW, Wardlaw JM (2012) Systematic review of perfusion imaging with computed tomography and magnetic resonance in acute ischemic stroke: heterogeneity of acquisition and postprocessing parameters: a translational medicine research collaboration multicentre acute stroke imaging study. Stroke 43(2):563–566CrossRefPubMedGoogle Scholar
  21. 21.
    Lansberg MG, Lee J, Christensen S, Straka M, De Silva DA, Mlynash M et al (2011) RAPID automated patient selection for reperfusion therapy: a pooled analysis of the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) and the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) Study. Stroke 42(6):1608–1614CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Mlynash M, Lansberg MG, De Silva DA, Lee J, Christensen S, Straka M et al (2011) Refining the definition of the malignant profile: insights from the DEFUSE-EPITHET pooled data set. Stroke 42(5):1270–1275CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Olivot J-M, Albers GW (2011) Diffusion-perfusion MRI for triaging transient ischemic attack and acute cerebrovascular syndromes. Curr Opin Neurol 24(1):44–49CrossRefPubMedGoogle Scholar
  24. 24.
    Rowley HA (2005) Extending the time window for thrombolysis: evidence from acute stroke trials. Neuroimaging Clin N Am 15(3):575–587, xCrossRefPubMedGoogle Scholar
  25. 25.
    Thomalla G, Cheng B, Ebinger M, Hao Q, Tourdias T, Wu O et al (2011) DWI-FLAIR mismatch for the identification of patients with acute ischaemic stroke within 4 · 5 h of symptom onset (PRE-FLAIR): a multicentre observational study. Lancet Neurol 10(11):978–986CrossRefPubMedGoogle Scholar
  26. 26.
    Kucinski T, Majumder A, Knab R, Naumann D, Fiehler J, Väterlein O et al (2004) Cerebral perfusion impairment correlates with the decrease of CT density in acute ischaemic stroke. Neuroradiology 46(9):716–722CrossRefPubMedGoogle Scholar
  27. 27.
    Fiehler J, Knudsen K, Kucinski T, Kidwell CS, Alger JR, Thomalla G et al (2004) Predictors of apparent diffusion coefficient normalization in stroke patients. Stroke 35(2):514–519CrossRefPubMedGoogle Scholar
  28. 28.
    Fiehler J, Foth M, Kucinski T, Knab R, von Bezold M, Weiller C et al (2002) Severe ADC decreases do not predict irreversible tissue damage in humans. Stroke 33(1):79–86CrossRefPubMedGoogle Scholar
  29. 29.
    Yoo AJ, Pulli B, Gonzalez RG (2011) Imaging-based treatment selection for intravenous and intra-arterial stroke therapies: a comprehensive review. Expert Rev Cardiovasc Ther 9(7):857–876CrossRefPubMedPubMedCentralGoogle Scholar
  30. 30.
    Baron JC (2001) Mapping the ischaemic penumbra with PET: a new approach. Brain 124(Pt 1):2–4CrossRefPubMedGoogle Scholar
  31. 31.
    Menon BK, d’Esterre CD, Qazi EM, Almekhlafi M, Hahn L, Demchuk AM et al (2015) Multiphase CT angiography: a New tool for the imaging triage of patients with acute ischemic stroke. Radiology 275(2):510–520CrossRefPubMedGoogle Scholar
  32. 32.
    Gonzalez RG (2012) Low signal, high noise and large uncertainty make CT perfusion unsuitable for acute ischemic stroke patient selection for endovascular therapy. J NeuroIntervent Surg 4(4):242–245CrossRefGoogle Scholar
  33. 33.
    Gonzalez RG, Copen WA, Schaefer PW, Lev MH, Pomerantz SR, Rapalino O et al (2013) The Massachusetts General Hospital acute stroke imaging algorithm: an experience and evidence based approach. J NeuroIntervent Surg 5(Supplement 1):i7–i12CrossRefGoogle Scholar
  34. 34.
    Schaefer PW, Souza L, Kamalian S, Hirsch JA, Yoo AJ, Kamalian S et al (2015) Limited reliability of computed tomographic perfusion acute infarct volume measurements compared with diffusion-weighted imaging in anterior circulation stroke. Stroke 46(2):419–424CrossRefPubMedPubMedCentralGoogle Scholar
  35. 35.
    Hacke W, Kaste M, Bluhmki E, Brozman M, Dávalos A, Guidetti D et al (2008) Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke. N Engl J Med 359(13):1317–1329CrossRefPubMedGoogle Scholar
  36. 36.
    Singer OC, Humpich MC, Fiehler J, Albers GW, Lansberg MG, Kastrup A et al (2008) Risk for symptomatic intracerebral hemorrhage after thrombolysis assessed by diffusion-weighted magnetic resonance imaging. Ann Neurol 63(1):52–60CrossRefPubMedGoogle Scholar
  37. 37.
    Lansberg MG, Thijs VN, Bammer R, Kemp S, Wijman CAC, Marks MP et al (2007) Risk factors of symptomatic intracerebral hemorrhage after tPA therapy for acute stroke. Stroke 38(8):2275–2278CrossRefPubMedPubMedCentralGoogle Scholar
  38. 38.
    Yoo AJ, Verduzco LA, Schaefer PW, Hirsch JA, Rabinov JD, Gonzalez RG (2009) 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 40(6):2046–2054CrossRefPubMedPubMedCentralGoogle Scholar
  39. 39.
    Yoo AJ, Barak ER, Copen WA, Kamalian S, Gharai LR, Pervez MA et al (2010) Combining acute diffusion-weighted imaging and mean transmit time lesion volumes with National Institutes of Health Stroke Scale Score improves the prediction of acute stroke outcome. Stroke 41(8):1728–1735CrossRefPubMedGoogle Scholar
  40. 40.
    Olivot J-M, Mosimann PJ, Labreuche J, Inoue M, Meseguer E, Desilles J-P et al (2013) Impact of diffusion-weighted imaging lesion volume on the success of endovascular reperfusion therapy. Stroke 44(8):2205–2211CrossRefPubMedPubMedCentralGoogle Scholar
  41. 41.
    Sanák D, Nosál V, Horák D, Bártková A, Zelenák K, Herzig R et al (2006) Impact of diffusion-weighted MRI-measured initial cerebral infarction volume on clinical outcome in acute stroke patients with middle cerebral artery occlusion treated by thrombolysis. Neuroradiology 48(9):632–639CrossRefPubMedGoogle Scholar
  42. 42.
    Jovin TG, Yonas H, Gebel JM, Kanal E, Chang Y-F, Grahovac SZ et al (2003) The cortical ischemic core and not the consistently present penumbra is a determinant of clinical outcome in acute middle cerebral artery occlusion. Stroke 34(10):2426–2433CrossRefPubMedGoogle Scholar
  43. 43.
    Hakimelahi R, Yoo AJ, He J, Schwamm LH, Lev MH, Schaefer PW et al (2012) Rapid identification of a major diffusion/perfusion mismatch in distal internal carotid artery or middle cerebral artery ischemic stroke. BMC Neurol 12:132CrossRefPubMedPubMedCentralGoogle Scholar
  44. 44.
    Schellinger PD, Bryan RN, Caplan LR, Detre JA, Edelman RR, Jaigobin C et al (2010) Evidence-based guideline: The role of diffusion and perfusion MRI for the diagnosis of acute ischemic stroke: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 75:177–185CrossRefPubMedPubMedCentralGoogle Scholar
  45. 45.
    Kidwell CS, Saver JL, Mattiello J, Starkman S, Vinuela F, Duckwiler G et al (2000) Thrombolytic reversal of acute human cerebral ischemic injury shown by diffusion/perfusion magnetic resonance imaging. Ann Neurol 47(4):462–469CrossRefPubMedGoogle Scholar
  46. 46.
    Guadagno JV, Warburton EA, Jones PS, Fryer TD, Day DJ, Gillard JH et al (2005) The diffusion-weighted lesion in acute stroke: heterogeneous patterns of flow/metabolism uncoupling as assessed by quantitative positron emission tomography. Cerebrovasc Dis 19(4):239–246CrossRefPubMedGoogle Scholar
  47. 47.
    Kranz PG, Eastwood JD (2009) Does diffusion-weighted imaging represent the ischemic core? An evidence-based systematic review. Am J Neuroradiol 30(6):1206–1212CrossRefPubMedGoogle Scholar
  48. 48.
    Chalela JA, Kang D-W, Luby M, Ezzeddine M, Latour LL, Todd JW et al (2004) Early magnetic resonance imaging findings in patients receiving tissue plasminogen activator predict outcome: Insights into the pathophysiology of acute stroke in the thrombolysis era. Ann Neurol 55(1):105–112CrossRefPubMedGoogle Scholar
  49. 49.
    Chemmanam T, Campbell BCV, Christensen S, Nagakane Y, Desmond PM, Bladin CF et al (2010) Ischemic diffusion lesion reversal is uncommon and rarely alters perfusion-diffusion mismatch. Neurology 75(12):1040–1047CrossRefPubMedGoogle Scholar
  50. 50.
    Campbell BCV, Purushotham A, Christensen S, Desmond PM, Nagakane Y, Parsons MW et al (2012) The infarct core is well represented by the acute diffusion lesion: sustained reversal is infrequent. J Cereb Blood Flow amp Metab 32(1):50–56CrossRefGoogle Scholar
  51. 51.
    Dani KA, Thomas RGR, Chappell FM, Shuler K, MacLeod MJ, Muir KW et al (2011) Computed tomography and magnetic resonance perfusion imaging in ischemic stroke: definitions and thresholds. Ann Neurol 70(3):384–401CrossRefPubMedGoogle Scholar
  52. 52.
    Kidwell CS (2013) MRI biomarkers in acute ischemic stroke: a conceptual framework and historical analysis. Stroke 44(2):570–578CrossRefPubMedGoogle Scholar
  53. 53.
    Fiorella D, Heiserman J, Prenger E, Partovi S (2004) Assessment of the reproducibility of postprocessing dynamic CT perfusion data. AJNR Am J Neuroradiol 25(1):97–107PubMedGoogle Scholar
  54. 54.
    Carroll TJ, Teneggi V, Jobin M, Squassante L, Treyer V, Hany TF et al (2002) Absolute quantification of cerebral blood flow with magnetic resonance, reproducibility of the method, and comparison with H2(15)O positron emission tomography. J Cereb Blood Flow Metab 22(9):1149–1156CrossRefPubMedGoogle Scholar
  55. 55.
    Wintermark M, Albers GW, Alexandrov AV, Alger JR, Bammer R, Baron JC et al (2008) Acute Stroke Imaging Research Roadmap. Stroke 39(5):1621–1628CrossRefPubMedGoogle Scholar
  56. 56.
    Bivard A, Krishnamurthy V, Stanwell P, Levi C, Spratt NJ, Davis S et al (2014) Arterial spin labeling versus bolus-tracking perfusion in hyperacute stroke. Stroke 45(1):127–133CrossRefPubMedGoogle Scholar
  57. 57.
    Bivard A, Levi C, Spratt N, Parsons M (2013) Perfusion CT in acute stroke: a comprehensive analysis of infarct and penumbra. Radiology 267(2):543–550CrossRefPubMedGoogle Scholar
  58. 58.
    Wintermark M, Flanders AE, Velthuis B, Meuli R, van Leeuwen M, Goldsher D et al (2006) Perfusion-CT assessment of infarct core and penumbra: receiver operating characteristic curve analysis in 130 patients suspected of acute hemispheric stroke. Stroke 37(4):979–985CrossRefPubMedGoogle Scholar
  59. 59.
    Wintermark M, Reichhart M, Thiran J-P, Maeder P, Chalaron M, Schnyder P et al (2002) Prognostic accuracy of cerebral blood flow measurement by perfusion computed tomography, at the time of emergency room admission, in acute stroke patients. Ann Neurol 51(4):417–432CrossRefPubMedGoogle Scholar
  60. 60.
    Butcher K, Parsons M, Baird T, Barber A, Donnan G, Desmond P et al (2003) Perfusion thresholds in acute stroke thrombolysis. Stroke 34(9):2159–2164CrossRefPubMedGoogle Scholar
  61. 61.
    Schaefer PW, Barak ER, Kamalian S, Gharai LR, Schwamm L, Gonzalez RG et al (2008) Quantitative assessment of core/penumbra mismatch in acute stroke: CT and MR perfusion imaging are strongly correlated when sufficient brain volume is imaged. Stroke 39(11):2986–2992CrossRefPubMedGoogle Scholar
  62. 62.
    Bivard A, McElduff P, Spratt N, Levi C, Parsons M (2011) Defining the extent of irreversible brain ischemia using perfusion computed tomography. Cerebrovasc Dis 31(3):238–245CrossRefPubMedGoogle Scholar
  63. 63.
    Bivard A, Levi C, Krishnamurthy V, Hislop-Jambrich J, Salazar P, Jackson B, Davis S, Parsons M (2014) Defining acute ischemic stroke tissue pathophysiology with whole brain CT perfusion. J Neuroradiol 41(5):307–315CrossRefPubMedGoogle Scholar
  64. 64.
    Kamalian S, Kamalian S, Maas MB, Goldmacher GV, Payabvash S, Akbar A et al (2011) CT cerebral blood flow maps optimally correlate with admission diffusion-weighted imaging in acute stroke but thresholds vary by postprocessing platform. Stroke 42(7):1923–1928CrossRefPubMedPubMedCentralGoogle Scholar
  65. 65.
    Campbell BCV, Christensen S, Levi CR, Desmond PM, Donnan GA, Davis SM et al (2011) Cerebral blood flow is the optimal CT perfusion parameter for assessing infarct core. Stroke 42(12):3435–3440CrossRefPubMedGoogle Scholar
  66. 66.
    Olivot J-M, Mlynash M, Thijs VN, Kemp S, Lansberg MG, Wechsler L et al (2009) Optimal Tmax threshold for predicting penumbral tissue in acute stroke. Stroke 40(2):469–475CrossRefPubMedPubMedCentralGoogle Scholar
  67. 67.
    Kamalian S, Kamalian S, Konstas AA, Maas MB, Payabvash S, Pomerantz SR et al (2012) CT perfusion mean transit time maps optimally distinguish benign oligemia from true “at-risk” ischemic penumbra, but thresholds vary by postprocessing technique. Am J Neuroradiol 33(3):545–549CrossRefPubMedPubMedCentralGoogle Scholar
  68. 68.
    Cenic A, Nabavi DG, Craen RA, Gelb AW, Lee T-Y (1999) Dynamic CT measurement of cerebral blood flow: a validation study. AJNR Am J Neuroradiol 20(1):63–73PubMedGoogle Scholar
  69. 69.
    Souza LCS, Yoo AJ, Chaudhry ZA, Payabvash S, Kemmling A, Schaefer PW et al (2012) Malignant CTA collateral profile is highly specific for large admission DWI infarct core and poor outcome in acute stroke. Am JNeuroradiol 33(7):1331–1336CrossRefGoogle Scholar
  70. 70.
    Angermaier A, Langner S, Kirsch M, Kessler C, Hosten N, Khaw AV (2011) CT-angiographic collateralization predicts final infarct volume after intra-arterial thrombolysis for acute anterior circulation ischemic stroke. Cerebrovasc Dis 31(2):177–184CrossRefPubMedGoogle Scholar
  71. 71.
    Agarwal S (2015) Is CT-based perfusion and collateral imaging sensitive to time since stroke onset? Front Neurol 6:1–7Google Scholar
  72. 72.
    Tan JC, Dillon WP, Liu S, Adler F, Smith WS, Wintermark M (2007) Systematic comparison of perfusion-CT and CT-angiography in acute stroke patients. Ann Neurol 61(6):533–543CrossRefPubMedGoogle Scholar
  73. 73.
    Bhatia R, Hill MD, Shobha N, Menon B, Bal S, Kochar P et al (2010) Low rates of acute recanalization with intravenous recombinant tissue plasminogen activator in ischemic stroke: real-world experience and a call for action. Stroke 41(10):2254–2258CrossRefPubMedGoogle Scholar
  74. 74.
    Vilela P, Goulão A (2005) Ischemic stroke: carotid and vertebral artery disease. Eur Radiol 15(3):427–433CrossRefPubMedGoogle Scholar
  75. 75.
    Lev MH, Farkas J, Rodriguez VR, Schwamm LH, Hunter GJ, Putman CM et al (2001) CT angiography in the rapid triage of patients with hyperacute stroke to intraarterial thrombolysis: accuracy in the detection of large vessel thrombus. J Comput Assist Tomogr 25(4):520–528CrossRefPubMedGoogle Scholar
  76. 76.
    Shrier DA, Tanaka H, Numaguchi Y, Konno S, Patel U, Shibata D (1997) CT angiography in the evaluation of acute stroke. AJNR Am J Neuroradiol 18(6):1011–1020PubMedGoogle Scholar
  77. 77.
    Knauth M, von Kummer R, Jansen O, Hähnel S, Dörfler A, Sartor K (1997) Potential of CT angiography in acute ischemic stroke. AJNR Am J Neuroradiol 18(6):1001–1010PubMedGoogle Scholar
  78. 78.
    Bash S, Villablanca JP, Jahan R, Duckwiler G, Tillis M, Kidwell C et al (2005) Intracranial vascular stenosis and occlusive disease: evaluation with CT angiography, MR angiography, and digital subtraction angiography. AJNR Am J Neuroradiol 26(5):1012–1021PubMedGoogle Scholar
  79. 79.
    Kim EY, Heo JH, Lee SK, Kim DJ, Suh S-H, Kim J et al (2006) Prediction of thrombolytic efficacy in acute ischemic stroke using thin-section noncontrast CT. Neurology 67(10):1846–1848CrossRefPubMedGoogle Scholar
  80. 80.
    Moftakhar P, English JD, Cooke DL, Kim WT, Stout C, Smith WS et al (2013) Density of thrombus on admission CT predicts revascularization efficacy in large vessel occlusion acute ischemic stroke. Stroke 44(1):243–245CrossRefPubMedGoogle Scholar
  81. 81.
    Fiehler J, Albers GW, Boulanger J-M, Derex L, Gass A, Hjort N et al (2007) Bleeding risk analysis in stroke imaging before thromboLysis (BRASIL): pooled analysis of T2*-weighted magnetic resonance imaging data from 570 patients. Stroke 38(10):2738–2744CrossRefPubMedGoogle Scholar

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© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Department of RadiologyUniversity of WisconsinMadisonUSA
  2. 2.NeuroradiologyHospital Beatriz ÂngeloLoures, LisbonPortugal

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