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22. European Stroke Conference 9 Brain imaging A 15:50 - 16:00 3T MR Spectroscopy assessment of metabolic changes in the recently salvaged human ischemic penumbra A. Bivard1, V. Krishnamurthy2, P. Stanwell3, C. Levi4, S. Davis5, M. Parsons6 University of Melbourne, Melbourne, AUSTRALIA1,University of Newcastle, Newcastle, AUSTRALIA2, University of Newcastle, Newcastle, AUSTRALIA3, University of Newcastle, Newcastle, AUSTRALIA4, University of Melbourne, Melbourne, AUSTRALIA5, University of Newcastle, Newcastle, AUSTRALIA6 We undertook a magnetic resonance spectroscopy (MRS) assessment of salvaged penumbra to investigate metabolic markers of tissue health. Methods: 30 ischemic stroke patients, presenting to hospital within 6 hours of symptom onset, with evidence of penumbra on acute CT perfusion imaging, were treated with IV thrombolysis and recruited. Twenty-four to 48 hours after isch-emia stroke onset, patients were scanned on 3T MRI using MRS (single voxel PRESS TE 30), and diffusion-weighted imaging (DWI). Spectroscopy voxels were placed in the salvaged pen-umbral grey matter tissue (as determined by comparing baseline CTP with follow-up DWI to identify previously hypoperfused areas that had not infarcted), and in the homologous contra-lateral region. Ten age-matched control participants were also enrolled in the study and under-went the same MRI/MRS protocol. Results: In reperfused penumbra, MRS showed significant metabolite changes when compared to the contralateral hemisphere (CH) and control grey mat-ter (CGM). Penumbra creatine (CR 3.58 range 2.67-6.74) was increased compared to CH (2.8 range 1.17-5.12, p 0.049) and CGW (2.53 range 1.74-3.81, 0.091), while penumbra glutamate (GLU, 5.94 range 2.93-7.58) was similar to the CH (5.71 range 3.72-7.84) and lower compared to CGM (6.9 range 6.17-7.8, p=0.046). Reperfused penumbra myo-inositol (INS, 3.61 range 1.49-6.6) was decreased compared to CH (4.7 range 3.59-6.14) and CGM (5.01 range 3.74- 5.89, p=0.05), while Lactate was increased in the penumbra (0.92 range 0-3.5) compared to the CH (0.55 range 0-1.98) and CGM (0.56 range 0-1.4). NAA showed a large range of values in the penumbra (5.68 range 2.13-7.11) compared to CH (6.33 range 5.01-7.73) and CGM (7.55 range 6.81-8.54). Discussion: Following reperfusion, despite normal structural imaging, the sal-vaged penumbra shows significant metabolite changes that may reflect tissue injury. However, it is uncertain how these metabolic changes relate to long term function of salvaged penumbra. 8 Brain imaging A 15:40 - 15:50 Evolution of the apparent diffusion coefficient (ADC) in acute stroke following thrombol-ysis. Results from the ongoing single-centre study “MR perfusion imaging during thromboly-sis” M. Kablau1, M. Griebe2, K. Szabo3, J. Gregori4, J. Sauter-Servaes5, M. Wolf6, P. Eisele7, A. Gass8, M.G. Hennerici9, M. Günther10, R. Kern11 Department of Neurology, UniversitaetsMedizin Mannheim, University of Heidelberg, Mannheim, GERMANY1,Department of Neurology, UniversitaetsMedizin Mannheim, Uni-versity of Heidelberg, Mannheim, GERMANY2, Department of Neurology, Universitaets- Medizin Mannheim, University of Heidelberg, Mannheim, GERMANY3, Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen, GERMANY4, Department of Neurology, UniversitaetsMedizin Mannheim, University of Heidelberg, Mannheim, GERMANY5, Depart-ment of Neurology, UniversitaetsMedizin Mannheim, University of Heidelberg, Mannheim, GERMANY6, Department of Neurology, UniversitaetsMedizin Mannheim, University of Hei-delberg, Mannheim, GERMANY7, Department of Neurology, UniversitaetsMedizin Mannheim, University of Heidelberg, Mannheim, GERMANY8, Department of Neurology, Universitaets- Medizin Mannheim, University of Heidelberg, Mannheim, GERMANY9, Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen, GERMANY10, Depart-ment of Neurology, UniversitaetsMedizin Mannheim, University of Heidelberg, Mannheim, GERMANY11 Introduction: Reduced apparent diffusion coefficient (ADC) of ischemic brain infarction is as-sumed to be caused by cytotoxic edema. Data about the early time course of ADC changes in hyperacute stroke are limited but have shown variable courses regarding size and ADC value evolution. Methods: Patients with acute symptoms suggestive of hemispheric stroke with time from symp-tom onset <4.5 hrs were examined with 3-Tesla stroke MRI including diffusion-weighted imag-ing (DWI) and ADC. After exclusion of cerebral hemorrhage, so far 18 patients have been treat-ed with IV tissue plasminogen activator (tPA) during continued MRI. 17 patients underwent follow-up MRI within 24-72h. If an acute lesion on DWI/ADC was confirmed on initial and/ or follow-up MRI (n = 13), we analyzed the difference of mean relative ADC values and of the lesion size between pre-treatment and follow-up MRI. Results: ADC characteristics were evaluated in 10 patients with embolic and in 3 patients with lacunar lesion patterns. At pre-treatment-MRI, there was a 17% mean reduction of the relative ADC. At follow-up, ADC values were highly dynamic with two different types of evolution: 7 patients had a further ADC decline (-15.8%), of whom 6 patients showed a progression of the lesion size. In 6 patients ADC values increased (+21.1%), of whom 4 showed an unchanged le-sion size or a partial reversibility of the lesion (n=1). Patients with decreasing ADC values were older (81 vs. 68 yrs; p=0.03), showed a worse early clinical outcome (median NIHSS on dis-charge 5 vs. 3; p=0.03) and a trend towards later tPA treatment (173 vs. 125 min; p=0.09). Conclusion: MRI during IV tPA is able to detect hyperacute ischemic tissue changes; ADC hy-pointensity might be reversible under certain conditions. The fate of ischemic tissue after IV tPA treatment is highly variable with either in- or decreasing ADC values. Decreasing ADC val-ues appear to be associated with older age, later treatment, infarct growth and worse outcome. 48 © 2013 S. Karger AG, Basel Scientific Programme


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