Page 231

Karger_ESC London_2013

London, United Kingdom 2013 5 Brain imaging Arterial spin labeling for hypoperfusion assessment in steno-occlusive disease: benefit of new approaches using transit delay adjustment S. Martin1, F. Samson2, V.I. Madai3, M. Mutke4, O. Zaro-Weber5, S. Hetzer6, M. Günther7, J. Sobesky8 Charité Berlin/ Centrum für Schlaganfallforschung Berlin (CSB), Berlin, GERMANY1, Fraun-hofer MEVIS, Bremen, GERMANY2, Charité Berlin/ Centrum für Schlaganfallforschung Berlin (CSB), Berlin, GERMANY3, Charité Berlin/ Centrum für Schlaganfallforschung Berlin (CSB), Ber-lin, GERMANY4, Max-Planck-Institute for Neurological Research, Cologne, GERMANY5, Berlin Center for Advanced Neuroimaging (BCAN), Berlin, GERMANY6, Fraunhofer MEVIS, Bremen, GERMANY7, Charité Berlin/ Centrum für Schlaganfallforschung Berlin (CSB), Berlin, GERMA-NY8 BACKGROUND: In magnetic resonance imaging (MRI), arterial spin labeling (ASL) allows for the measurement of cerebral blood flow (CBF) without the need of an exogenic contrast agent. A major current limita-tion of this technique is the sensitivity to arterial transit delay (ATD) as present in vessel pathology. We evaluated a novel ASL technique (3D-GRASE) with ATD adjustment in comparison to standard DSC (dynamic susceptibility contrast)-MRI in patients with steno-occlusive disease. METHODS: As part of a prospective, WHO-registered study (“PEGASUS”, registration number: DRKS00003198) patients with unilateral steno-occlusion of the ICA or MCA (internal or middle cerebral artery) >70% were imaged on a Magnetom Tim Trio 3T system (Siemens/Germany) as follows. 3D-GRASE: 20 inversion times (TI), range 300 ms-3150 ms; DSC-MRI: single-shot GRE-EPI; 5 ml Gadovist®. DSC maps for CBF and time to peak (TTP) were generated off-line (PMA, ASIST-Japan). ASL maps for relative CBF and bolus-arrival-time (BAT) were generated off-line (Fraunhofer MEVIS tool). After visual rating, cortical ROIs (regions of interest, diameter 20 mm, n=120 per patient) were used for further comparison of CBF values (Spearman, Bland-Altman (BA) plot, relative ROI values for pooled analysis). RESULTS: In 27 patients, the maps of CBF and TTP/BAT showed a good qualitative agreement between ASL and DSC technique with respect to site, extent and severity of hypoperfusion/tracer delay (Fig. 1). In the pooled ROI analysis, a significant correlation was found for ASL and DSC based CBF values (rho=0.55; p<0.0001). The BA plot found no bias, a small average difference, but a relevant varia-tion E-Poster Session Red Cerebrovasc Dis 2013; 35 (suppl 3)1-854 231 of differences. CONCLUSION: Our preliminary results suggest that new ASL sequences (e.g. 3D GRASE with Multi-TI) with ad-justment for arterial transit delay, may allow for an improved estimation of CBF and hypoperfusion by ASL in patients with steno-occlusive disease.


Karger_ESC London_2013
To see the actual publication please follow the link above