Table 3

Overview of different MeVO stroke imaging protocols

MeVO stroke imaging protocolsStudies in which the protocol was usedAdvantagesDisadvantages
NCCT+CTARomano et al 202027 (+DWI if symptom onset unknown)
Atchaneeyasakul et al 202046
Compagne et al 201923
Qureshi et al 201748
Sarraj et al 201649
Menon et al 2019 24 (CTP/MRI was available in some patients)
Coutinho et al 201650
Bhogal et al 201752 (either NCCT+CTA or MRI)
De Castro Afonso et al 201926
Grieb et al 201930
  • Wide availability

  • Inexpensive

  • Fast

  • Robust against patient motion

  • No post-processing needed

  • Option to use multiphase CTA, including color-coded time-variant mCTA maps and mCTA-derived CTP-like maps14 58

  • If single-phase CTA is used MeVOs may be missed59

  • Little information about collateral status if single-phase CTA is used

  • Current ASPECTS thresholds for LVO EVT are probably not optimal for MeVO EVT

  • ASPECTS does not capture ischemic changes in ACA and PCA MeVO stroke

NCCT+CTA + CTPHaussen et al 2020a34
Jiang et al 201925
Vargas et al 201737
Navia et al 201629
Menon et al 2019 24 (CTP/MRI was available in some patients)
Coutinho et al 201650 (CTP/MRI was available in some patients)
Grossberg et al 201845
Altenbernd et al 201828
Pfaff 201654 (either NCCT+CTA + CTP or DWI+MRA + PWI)
  • Higher information content compared with NCCT+CTA only

  • Estimates for ischemic penumbra and “core” volumes, also for ACA and PCA MeVO stroke

  • Does not exclusively rely on ASPECTS for ischemic “core” assessment

  • Option to use either single or multiphase CTA

  • Unvailability or limited availability of CTP in smaller hospitals

  • Limited accuracy of “core” and penumbra estimates due to variability in post-processing mechanisms

  • Susceptibility to patient motion

MRI (DWI-MRI±PWI)Romano et al 202027 (NCCT +CTA, DWI only if symptom onset unknown)
Menon et al 201924 (CTP/MRI was available in some patients)
Bhogal et al 201752 (either NCCT+CTA or MRI)
Pfaff et al 201654 (either NCCT+CTA + CTP or DWI+MRA + PWI)
  • DWI: Highest sensitivity for acute small infarcts

  • PWI: Estimates ischemic penumbra and “core” volumes, also for ACA and PCA MeVO stroke

  • Limited availability of MRI and particularly PWI in many hospitals

  • Contraindications

  • Limited accuracy of PWI “core” and penumbra estimates due to variability in post-processing mechanisms

  • Susceptibility to patient motion

  • Various pitfallsin MRI interpretation due to artifacts (eg, slow flow, metal artifacts due to dental fillings, etc.)

  • NCCT = non contrast head CT, CTA = CT angiography, CTP = CT perfusion, DWI = diffusion-weighted imaging, MRA = MR angiography, PWI = perfusion-weighted imaging, ACA = anterior cerebral artery, PCA = posterior cerebral artery, LVO = large vessel occlusion, ASPECTS = Alberta Stroke Program Eearly CT Score