22. European Stroke Conference 231 Brain imaging Enlarged perivascular spaces in cerebral amyloid angiopathy A. Charidimou1, Z. Jaunmuktane2, JC. Baron3, P. Varlet4, A. Peeters5, H.R. Jäger6, S. Brandner7, D.J. Werring8 Stroke Research Group, UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London, UNITED KINGDOM1, Division of Neuropathology and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UNITED KINGDOM2, Department of Clinical Neurosciences, University of Cambridge, Adden-brooke’s Hospital, Cambridge, UNITED KINGDOM3, Department of Neuropathology, Hospital Sainte-Anne, and University Paris Descartes, Paris, FRANCE4, Department of Neurology, Cliniques Universitaires UCL Saint Luc, Avenue Hippocrate, Brussels, BELGIUM5, Lysholm Department of Neuroradiology, UCL Institute of Neurology and National Hospital for Neurology and Neurosur-gery, London, UNITED KINGDOM6, Division of Neuropathology and Department of Neurodegen-erative Disease, UCL Institute of Neurology, Queen Square, London, UNITED KINGDOM7, Stroke Research Group, UCL Institute of Neurology and The National Hospital for Neurology and Neuro-surgery, Queen Square, London, UNITED KINGDOM8 Background: Cerebral amyloid angiopathy (CAA) is a common age-related small vessel disease, associated with lobar intracerebral haemorrhage (ICH) and cognitive impairment. The gold standard for CAA diagnosis is histopathological analysis; new non-invasive diagnostic markers are therefore needed. We investigated enlarged perivascular spaces (EPVS) on MRI - a recently-recognized indi-cator of small vessel disease. We tested the hypothesis that the prevalence of more severe centrum semiovale EPVS would be higher in patients with CAA compared to patients with non-CAA related spontaneous ICH. Methods: We analysed consecutive patients with histopathologically confirmed CAA and patients with spontaneous ICH but no evidence of CAA on histopathology, as a control group. EPVS were rated on axial T2-weighted MR images in basal ganglia and centrum semiovale using a validated 4-point visual rating scale. The sensitivity and specificity of existing diagnostic criteria for patholog-ically proven CAA with and without the addition of severe centrum semiovale EPVS were calculat-ed. Results: A total of 15 CAA patients and 10 control non-CAA ICH patients were included in our study. Severe centrum semiovale EPVS were present in 12/15 (80%) patients with CAA compared to 1/10 (10%) controls (p=0.001). There was no difference in the prevalence basal ganglia EPVS in the two groups. The “classic” Boston criteria showed a sensitivity of 92.9% (95% CI 66–99.8%), while inclusion of centrum semiovale EPVS score >20 in the criteria increased their sensitivity to 100% (95% CI 76.8–100%) (not statistically significant) without lowering the specificity. Conclusion: Our data suggest that severe centrum semiovale EPVS are a promising new neuroim-aging marker to aid the in vivo diagnosis of CAA. These findings require confirmation in larger co-horts with pathological verification of CAA, to determine whether this marker usefully increases the sensitivity of current diagnostic criteria. 408 © 2013 S. Karger AG, Basel Scientific Programme 232 Brain imaging Quantitated T1 and T2 MRI in acute ischemic stroke: A step towards a “Tissue Window” Therapeutic Paradigm S. Mishra1, R. Kosior2, V. Nambiar3, S. Bal4, R. Frayne5, M.L. Lauzon6, U. Tuor7, P.A. Barber8 Calgary Stroke Program, Foothills Medical Centre, University of Calgary, Calgary, CANA-DA1, Siemens Family MR Centre, Foothills Medical Centre, University of Calgary, Calgary, CAN-ADA2, Calgary Stroke Program, Foothills Medical Centre, University of Calgary, Calgary, CANA-DA3, Health Sciences Centre, University of Manitoba, Winnipeg, CANADA4, Siemens Family MR Centre, Foothills Medical Centre, University of Calgary, Calgary, CANADA5, Siemens Family MR Centre, Foothills Medical Centre, University of Calgary, Calgary, CANADA6, Siemens Family MR Centre, Foothills Medical Centre, University of Calgary, Calgary, CANADA7, Calgary Stroke Pro-gram, Foothills Medical Centre, University of Calgary, Calgary, CANADA8 Background: The “time window” paradigm restricts availability of acute stroke therapies, and concerns remain over potentially devastating hemorrhagic transformation. We hypothesize that quantitative (q) MRI T1 and T2 provides an index of stroke severity, predicting response to treatment stratified by the “tissue properties” of ischemic brain. Methods: Acute ischemic stroke patients with confirmed middle cerebral artery occlusion on CT Angiography were imaged with MRI (3T) within 6 hours of symptom onset and at 24 hours. T1 mapping was per-formed based on a 3D-GRE-LL sequence (22 phases, FA/TI/TR = 3.5 degree/13 ms/3 ms) or a DES-POT1 sequence (two SPGR acquisitions, FA =4 ms and FA = 18 ms, with TR = 7.5 ms). T2 mapping was performed using CPMG sequence (eight echo times, 30 ms to 240 ms) or 16 echo times (15 to 240 ms). Volumetric and absolute value analysis of the infarct core was conducted on the ADC, T1 and T2 maps. Results: Fourteen patients were included. Median NIHSS was 15. Median time from onset to first MRI was 228 min (IQR-177). Eleven had detectable ADC lesions; median infarct volume on ADC increased from 13 ml (37) at baseline to 29 ml (66) at 24 hrs. Distinct differences in qT1 and qT2 evolution were observed. Eight (57%) patients showed early T1 changes on the initial MRI (Image1). These changes reversed in 3 patients at 24 hours (Image2). The median absolute ipsi-contralateral T1 value was 314 ms (322) at baseline and 42 ms (236) at 24 hrs. For T2, median absolute ipsi-contralateral values were 23 ms (25) at baseline and 39 ms (34) at 24 hrs. Conclusion: This study shows the presence of qT1 and qT2 changes in acute ischemic stroke. Presence of qT2 concomitant to reduced ADC suggests the existence of both cytotoxic and vasogenic edema. These findings suggest qMRI can define ischemic “tissue properties”, and may help in determining stroke severity and the risk of hemorrhagic transformation.
Karger_ESC London_2013
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