Neurointervention.  2021 Mar;16(1):20-28. 10.5469/neuroint.2020.00199.

A Multicenter Survey of Acute Stroke Imaging Protocols for Endovascular Thrombectomy

  • 1Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, Korea
  • 2Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea


Identifying current practices in acute stroke imaging is essential for establishing optimal imaging protocols. We surveyed and assessed the current status of acute stroke imaging for endovascular thrombectomy (EVT) at tertiary hospitals throughout South Korea.
Materials and Methods
An electronic questionnaire on imaging protocols for EVT in patients with acute ischemic stroke was e-mailed to physicians at 42 registered tertiary hospitals, and their responses were collected between February and March 2020.
Of the 36 hospitals participating in the survey, 69% (25/36) adopted computed tomography (CT)-based protocols, whereas 31% (11/36) adopted magnetic resonance (MR)-based protocols. Non-enhanced CT (NECT) was the initial imaging study at 28%, NECT with CT angiography (CTA) at 36%, and NECT with CTA and CT perfusion (CTP) at 33% of hospitals. Perfusion imaging was performed at 61% (22/36), CTP at 44% (16/36), and MR perfusion at 17% (6/36) of hospitals. Multiphase CTA was performed at 67%, single-phase CTA at 11%, time-of-flight MR angiography (MRA) at 8%, contrast-enhanced MRA at 8%, and both at 6% of hospitals. For late time window stroke, 50% of hospitals used identical imaging protocols to those for early time window stroke, 39% used additional MR imaging (MRI), and 6% converted the imaging strategy from CT to MRI. Post-processing programs were used at 28% (10/36), and RAPID software at 14% (5/36) of hospitals, respectively. Most hospitals (92%) used the same imaging protocols for posterior and anterior circulation strokes.
Our multicenter survey demonstrated considerable heterogeneity in acute stroke imaging protocols across South Korean tertiary hospitals, suggesting that hospitals refine their imaging protocols according to hospital-specific conditions.


Acute stroke; Thrombectomy; Cerebrovascular stroke


  • Fig. 1. Summary of initial imaging modalities adopted at the participating hospitals. (A) Hospitals adopting computed tomography (CT)-based imaging protocols. (B) Hospitals adopting magnetic resonance-based imaging protocols. DWI, diffusion-weighted imaging; NECT, non-enhanced CT; CTA, CT angiography; CTP, CT perfusion. *”+” implies imaging acquisition in a single session.

  • Fig. 2. Use of perfusion-weighted imaging in routine protocols. (A) Hospitals adopting computed tomography (CT)-based imaging protocols. (B) Hospitals adopting magnetic resonance (MR)-based imaging protocols. CTP, CT perfusion; MRP, MR perfusion.

  • Fig. 3. Detailed technique of noninvasive vascular study in routine protocols. CTA, computed tomography angiography; ToF MRA, time-of-flight magnetic resonance angiography; CE MRA, contrast-enhanced magnetic resonance angiography.

  • Fig. 4. Routine imaging protocols for patients presenting in a late time window. *Further acquisition of magnetic resonance imaging (MRI) after routine computed tomography (CT)-based imaging protocols used in patients presenting in an early time window. †Converting the routine imaging strategy from CT-based to MR-based protocols. ‡Further acquisition of MR perfusion or switching fast MR to conventional MR techniques.

  • Fig. 5. Current usage status of post-processing software programs. OLEA, olea sphere; VITREA, vitrea intelligence; IN-HOUSE, in-house program.


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