Multi-delay ASL can identify leptomeningeal collateral perfusion in endovascular therapy of ischemic stroke

// Xin Lou 1 , Songlin Yu 2 , Fabien Scalzo 2 , Sidney Starkman 2 , Latisha K. Ali 2 , Doojin Kim 2 , Neal M. Rao 2 , Jason D. Hinman 2 , Paul M. Vespa 2 , Reza Jahan 3 , Satoshi Tateshima 4 , Nestor R. Gonzalez 5 , Gary R. Duckwiler 6 , Jeffrey L. Saver 2 , Bryan Yoo 3 , Noriko Salamon 3 , Jinhao Lyu 1 , Lin Ma 1 , Danny JJ Wang 2 and David S. Liebeskind 2 1 Department of Radiology, Chinese PLA General Hospital, Beijing, China 2 Department of Neurology, UCLA Stroke Center, Los Angeles, California, USA 3 Department of Radiology, UCLA Stroke Center, Los Angeles, California, USA 4 Department of Medical Center, UCLA Stroke Center, Los Angeles, California, USA 5 Department of Neurosurgery/Interventional Neuroradiology, UCLA Stroke Center, Los Angeles, California, USA 6 Department of Radiology and Neurosurgery, UCLA Stroke Center, Los Angeles, California, USA Correspondence to: David S Liebeskind, email: // Keywords : collateral circulation; stroke; perfusion imaging; arterial spin-labeling; cerebral blood flow Received : October 21, 2016 Accepted : November 24, 2016 Published : December 10, 2016 Abstract Background and Purpose: Multi-delay arterial spin-labeling (ASL) perfusion imaging has been used as a promising modality to evaluate cerebral perfusion. Our aim was to assess the association of leptomeningeal collateral perfusion scores based on ASL parameters with outcome of endovascular treatment in patients with acute ischemic stroke (AIS) in the middle cerebral artery (MCA) territory. Materials and Methods: ASL data at 4 post-labeling delay (PLD) times (PLD = 1.5, 2, 2.5, 3 s) were acquired during routine clinical magnetic resonance examination on AIS patients prior to endovascular treatment. A 3-point scale of leptomeningeal collateral perfusion grade on 10 anatomic regions was determined based on arterial transit times (ATT), cerebral blood flow (CBF), and arterial cerebral blood volume (CBV), estimated by the multi-delay ASL protocol. Based on a 90-day modified Rankin Scale (mRS), the patients were dichotomized to moderate/good (mRS 0–3) and poor outcome (mRS 4–6) and the regional collateral flow scores were compared. Results: Fifty-five AIS patients with unilateral MCA stroke (mean 73.95±14.82 years) including 23 males were enrolled. Compared with poor outcome patients, patients with moderate to good outcomes had a significantly higher leptomeningeal collateral perfusion scores on CBV (3.01±2.11 vs. 1.82±1.51, p =0.024) but no differences on scores on CBF (2.31±1.61 vs. 1.66±1.32, p =0.231) and ATT (2.67±2.33 vs. 3.42±3.37, p =0.593). Conclusions: Higher leptomeningeal collateral perfusion scores on CBV images by ASL may be a specific marker of clinical outcome after endovascular treatment in patients with acute MCA ischemic stroke. Further study with larger sample size is warranted.