Posters SSNR no significant correlation between the time-to-treat, recanalisation rate and the clinical outcome. Significant baseline predictors were the NIHSS on admission and GCS. All four DWI-scoring systems significantly correlated with the clinical outcome. The multivariate analysis revealed that the herein proposed DWIscore was a more reliable predictor of functional outcome (P = 0.004). Conclusion: DWI is a strong predictor for clinical outcome in BAO treated by IAT. The proposed DWI-scoring is a simplified, clinically-weighted scoring system slightly outperformed the previously published scoring systems. Still, the therapeutic decision must be discussed in an interdisciplinary team, including neurologists, and must be guided by the clinical status of the patient. 138 Angiocentric Glioma: A Case Report and Comparison of Imaging findings C. Amaxopoulou 1 , A Pangalu 1 , R.A. Kockro 2 , H. Dohmen- S<strong>ch</strong>eufler 3 , A. Valavanis 1 1 Department of Neuroradiology, University Hospital Züri<strong>ch</strong>, Züri<strong>ch</strong>, Switzerland, 2 Department of Neurosurgery, University Hospital Züri<strong>ch</strong>, Züri<strong>ch</strong>, Switzerland, 3 Department of Neuropathology, University Hospital Züri<strong>ch</strong>, Züri<strong>ch</strong>, Switzerland Introduction: In 2007 the World Health Organization renewed the classification of tumors of the Central Nervous System: Angiocentric glioma was established as a new clinicopathological entity of brain tumors. We present the first case of angiocentric glioma in our institution and overview the current literature of reported cases particularly related to imaging findings. Methods: We report of a nine year old <strong>ch</strong>ild with angiocentric glioma suffering from persistent seizures whi<strong>ch</strong> could not be controlled with medical treatment. We evaluated the MRI and CT findings as well as the histopathologic features in context with the current literature. Results: In this case CT presented a hypodense, non-enhancing lesion of the left mesial temporal lobe. On MR imaging the lesion was non-enhancing and hypointense on T1. It was hyperintense on fluid-attenuated inversion recovery and T2. Microscopically the tumor consisted of monomorphous, bipolar tumor cells with a conspicuous perivascular arrangement in terms of pseudorossetes. The tumor cells were positive reactive for vimentin and glial fibrillary acidic protein and showed epithelial membrane antigene positive “dot like” reactions. Initially a subtotal tumor resection was performed followed by gross total resection due to persistent seizures. On the first follow-up three months after surgery the patient was seizure free and without neurological deficits. Conclusions: We compared our findings with 26 cases in the literature. Seizures were reported the most frequent symptom. Findings on CT and MR imaging were identical to the case reported here. In all but one of the reported cases, complete resection resulted in a long term seizure- and recurrence-free outcome. Complete surgical resection should be the primary goal of treatment in this histological entity. 139 Application of drug-eluting stents for the treatment of symptomatic intracranial stenosis: Preliminary results J. Abu-Isa, P. Mordasini, C. Brekenfeld, U. Fis<strong>ch</strong>er, M. Arnold, M.L. Mono, D. Do, J. Gralla, G. S<strong>ch</strong>roth Inselspital, Bern, Switzerland Introduction: Intracranial stenting for treatment of symptomatic intracranial stenosis is a relatively novel approa<strong>ch</strong> but has been widely applied in the recent years. Although the proceduralrelated complication rate is low the early in-stent re-stenosis rate of these dedicated “bare metal stents” is a matter of concern in the delicate intracranial anatomical setting. Although low restenosis rates have been shown for drug-eluting stents in the cardiovascular field, no data on the intracranial application is available. Methods: Between 2003 and 2009 eleven patients (7 male, 4 female, mean age 57.7 years) were treated with drug-eluting stents (Xience, Endeavor, Promus) for symptomatic intracranial stenosis. Follow-up was performed using trans-cranial ultraso<strong>und</strong> (TCD), magnetic resonance imaging (MRI) and angiography (DSA). Location of target lesion was the intracranial internal carotid artery (ICA) in three cases, vertebral artery (VA) in three cases, medial cerebral artery (MCA) in three cases and the basilar artery (BA) in two cases. Results: The application of the stents was feasible in all cases. Mean follow-up interval was 13.6 months including 10 patients (one patient developed a post-interventional fatal cerebral hyperperfusion syndrome). In nine patients follow-up did not show relevant re-stenosis. In one case of an MCA stenosis TCD revealed asymptomatic (50%) re-stenosis after 3.5 years. Conclusion: The application of drug-eluting stents in the treatment of symptomatic intracranial stenosis is te<strong>ch</strong>nically feasible. The re-stenosis rate in this small group of patients is very low and indicates a positive effect of the drug-eluting stent on pathome<strong>ch</strong>anism of intracranial in-stent re-stenosis. 140 Assessment of cerebral blood flow by selective vessel encoding arterial spin labeling: Ready to <strong>ch</strong>allenge angiography? R. Wiest 1 , M. Hauf 1 , J. Gralla 1 , K. Jann 2 , G. S<strong>ch</strong>roth 1 , H. Mattle 3 , JJ. Wang 4 , A. Federspiel 1 1 Neuroradiology, Inselspital Bern, Switzerland, 2 Psy<strong>ch</strong>iatric Neurophysiology, Psy<strong>ch</strong>iatric University Hospital Bern, Switzerland, 3 Neurology, Inselspital Bern, Switzerland, 4 Neurology and Neuroradiology, University of Pennsylvania, United States Introduction: Arterial Spin Labeling (ASL) is a quickly developing te<strong>ch</strong>nique with a wide range of applications in the field of neuroradiology and neurology. ASL is noninvasive, fast and provides a quantified measure of blood flow in units of ml/100 g/min. Recent advances in ASL have permitted noninvasive evaluation of vascular territories to investigate perfusion deficits and collateral blood flow. Methods: We have tested selective vessel-encoded ASL in ten patients with extra- and intracranial occlusive disease (seven patients with carotid artery (CA) stenosis and three patients with middle cerebral artery (MCA) stenosis. The method was paralleled by non invasive MR-angiography and Digital Subtraction Angiography (DSA). Imaging was performed on a Siemens 3T Trio scanner (Siemens, Erlangen, Germany). Tagging duration was 1375 ms for the tagging pulse train. The post labeling delay was 1000 ms and TR/TE was 3000 ms/52 ms. A total of 20 images were acquired for a set of six cycles. Analysis and computation of selective ASL maps were performed using self written Matlab programs (MathWorks, Inc., Natick, USA). Results: Mean CBF showed a 40% decrease in the affected hemisphere supplied by the stenotic carotid artery (37.7 ml/100 g/min vs. 22.6 ml/100 g/min). In patients with MCA stenosis there was a 31% decrease compared to the contralateral hemisphere (26 ml/100g/min vs. 18 ml/100g/min). In three patients that <strong>und</strong>erwent internal carotid artery stenting mean CBF in the affected hemisphere increased by 29% (from 25 ml/100 g/min to 35 ml/100 g/min) after treatment with marked extension of the supplied vascular territory. Visual analysis of the CBF map in 7 untreated patients allowed a discrimination of 1) the territorial supply of the middle and anterior cerebral artery and 2) anterior cross flow to the affected hemisphere in accordance with DSA. Discrimination between anterior and posterior circulation supply was conclusive only in two patients with CA stenosis compared with DSA. Conclusion: Vessel-encoded ASL may be currently used to map the anterior cerebrovascular territories, anastomoses and treatment response of patients with cerebrovascular disease non-invasively. The discrimination of the anterior and posterior circulation, however, is still a <strong>ch</strong>allenging issue due to confo<strong>und</strong>ing labeling effects at the carotid level during basilar artery tagging. In contrast, angiography must be considered as the “un<strong>ch</strong>allenged” gold standard up to now. This work has been partially granted by the SNF Grant (SPUM) 33CM30-124114 Impact of qualitative MR perfusion imaging on the management of patients with carotid artery disease. Cerebral microbleeds and iron deposition in deep grey matter based on SWI discriminate stable versus progressive mild cognitive impairment (MCI) Sven Haller 1 , A. Barts<strong>ch</strong> 4 , Duy Nguyen 1 , C. Rodriguez 2 , J. Em<strong>ch</strong> 2 , G. Gold 3 , K.O. Lovblad 1 , P. Giannakopoulos 2 1 Neuroradiology, Geneva, Switzerland, 2 Division of Old Age Psy<strong>ch</strong>iatry, Department of Psy<strong>ch</strong>iatry, Geneva, Switzerland, 3 Department of Rehabilitation and Geriatrics, Geneva, Switzerland, 4 Neuroradiology, Heidelberg, Germany 141 SCHWEIZER ARCHIV FÜR NEUROLOGIE UND PSYCHIATRIE 2010;161(4):3–51 www.sanp.<strong>ch</strong> | www.asnp.<strong>ch</strong> 43 S
Posters SSNR Introduction: We investigated whether stable versus progressive mild cognitive impairment (sMCI, pMCI) subjects can be discriminated based on cerebral microbleeds and iron deposition in deep grey matter. Methods: Susceptibility weighted imaging (SWI) was assessed at baseline in 35 healthy controls (HC) and 69 MCI subjects. At follow-up after one year, 40 MCI subjects remained stable (sMCI), while 27 MCI progressed (pMCI), 2 subjects were lost upon follow-up. Cerebral microbleeds were visually analyzed by two experienced neuroradiologists in consensus. Iron deposition in deep grey matter was assessed in a voxel based morphometry (VBM) like voxel-wise statistical analysis after non-linear spatial registration. Results: The number of microbleeds was significantly higher in MCI compared to HC (p
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