Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment

PLoS One. 2016 Jan 29;11(1):e0147910. doi: 10.1371/journal.pone.0147910. eCollection 2016.

Abstract

Introduction: The capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned.

Methods: 62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded.

Results: Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS ≤ 2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome.

Conclusions: Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Blood Flow Velocity / drug effects
  • Blood Volume / drug effects
  • Brain Ischemia / diagnosis*
  • Brain Ischemia / diagnostic imaging
  • Brain Ischemia / drug therapy
  • Brain Ischemia / pathology
  • Cerebral Angiography
  • Cerebrovascular Circulation / drug effects
  • Cerebrum / blood supply
  • Cerebrum / drug effects
  • Cerebrum / pathology
  • Female
  • Fibrinolytic Agents / therapeutic use
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Angiography*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Stroke / diagnosis*
  • Stroke / diagnostic imaging
  • Stroke / drug therapy
  • Stroke / pathology
  • Tomography, X-Ray Computed
  • Treatment Outcome

Substances

  • Fibrinolytic Agents

Grant support

This work has been supported by Italian National Health System- Research Program entitled “Nuove conoscenze e problematiche assistenziali nell’ictus cerebrale: un Programma Strategico di Ricerca e Sviluppo” ex art. 12-12bis/D.Lgs n. 502/92, PG/2007/0293184. The authors would also like to thank the Canadian Stroke Network and European Stroke Network, Canadian Institutes of Health Research, Ontario Research Fund and GE Healthcare for partial support of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.