Abstract #2120

Accordance of ASL Delay Time & Bolus Arrival Times in Parenchyma

Kay Jann¹, Martinus Hauf², Frauke Kellner-Weldon², Marwan Mohamed El-Koussy², Claus Kiefer², Andrea Federspiel¹, Gerhard Schroth²

¹Department of Psychiatric Neurophysiology, University Hospital of Psychiatry / University of Bern, Bern, Switzerland; ²University Institute of Diagnostic & Interventional Neuroradiology, Inselspital & University of Bern, Bern, Switzerland

The time needed by labelled blood to reach the cortical capillaries (parenchyma phase) has to be accounted for in ASL, therefore a delay between labelling and readout is introduced. The duration of this delay is limited by the fast T1 relaxation-time to only a few seconds. In patients with steno-occlusive arterial disease (SOAD) above the labelling plane (intracranial stenosis) this time window might be too narrow due to prolonged arrival times to the parenchyma. We estimated to what extent arrival is delayed in patients with SOAD and from which vascular compartment the ASL signal origins at a given delay time.