Edinburgh Imaging

Acute CTA for Thrombectomy in Stroke (ACTATS)

ACTATS teaches about CT & CTA review & interpretation in the context of thrombectomy. A Medtronic educational development grant, as well as support from the Thrombectomy Advisory Group & NHS National Services Scotland, enables free registration & access.

ACTATS Acute CTA for Thrombectomy in Stroke


  • We will send you a password for logging in
  • Registration is free due to:


  • ACTATS launched on 07 May 2020
  • Set aside seven (7) hours to work through all materials



The Acute CT Angiography for Thrombectomy in Stroke (ACTATS) training tool has been developed in preparation for the launch of a Scotland-wide thrombectomy service.

Creation of this tool was supported by educational development grants from Medtronic.

The creation of this tool was also supported by the Thrombectomy Advisory Group, NHS Scotland & NHS National Services Scotland.



  • Three (3) didactic lectures
    1. Basic CT interpretation in stroke
    2. CTA Anatomy of the head & neck
    3. Acute CTA for Thrombectomy in Stroke (ACTATS)
  • MCQs to test your learning from the didactic lectures
  • A series of 28 validated, plain CT & CTA stroke cases for practice
  • A five (5) question feedback survey to help us improve the training tool
  • A certificate of completion, downloadable after you complete all MCQs, all cases & all feedback survey questions
    • You will see the link to the certificate once you complete the feedback survey

The third didactic lecture, Acute CTA for Thrombectomy in Stroke (ACTATS), covers approaches to assessing CT Angiography (CTA), which have been used in various thrombectomy & thrombolysis trials.

While the approach may change in the future, the current combination of lectures, MCQs & cases will help you develop a systematic approach to CTA.

The series of 28 validated, plain CT & CTA stroke cases are all real cases collated from the International Stroke Trial 3 (IST-3)

  • The interface allows you to select & manipulate images similarly to a PACS session.
  • Each case includes a structured questionnaire to help you develop a systematic approach to acute stroke CT / CTA review.
  • Feedback includes seeing how an expert panel of Neuroradiologists approached each case & question.



Participation is eligible for CPD / CME.

  • We expect each lecture & MCQ to take 40 minutes to complete i.e. set aside 2 hours for all of them.
  • We expect the 28 validated cases to take 5 hours to complete.
  • This course provides 7 CPD credits in accordance with the CPD Scheme of the Royal College of Radiologists.
  • The exit certificate states this credit allocation & is downloadable after you complete all MCQs, all cases & all feedback survey questions.
    • You will see the link to the certificate once you complete the feedback survey


Learning objectives

Lecture 1: Basic CT interpretation in stroke.
  • An approach to plain CT brain scans in the context of hyperacute / acute stroke
  • Learning objectives:
    • State the role of CT in stroke work-up
    • List basic findings in CT stroke imaging including those associated with:
      • Haemorrhage
      • Infarct
    • Re-enforce the above objectives through case review


Lecture 2: CTA anatomy of the head & neck.
  • Anatomical orientation to head & neck arteries as they appear on CTA.
  • Learning objectives:
    • Describe technical factors for CTA acquisition
    • List normal neck arteries & their relationships
    • Identify neck arteries on cross-sectional CTA images


Lecture 3: Acute CTA for thrombectomy in stroke (ACTATS).
  • An approach to CT Angiography, specifically with a view to identifying thrombectomy candidates
  • Learning objectives:
    • State the aims of angiographic imaging
    • List different angiographic imaging modalities
    • Describe CTA acquisition & display
    • Compare 3D & 4D CTA displays
    • Interpret basic CTA in the context of stroke
    • Discuss the role of CTA in stroke decision making
    • State the limitations of CTA


FAQ: Who are Readers 1,2 & 3, are these students on the course or neuroimaging specialists?

  • Readers 1, 2 & 3 are all experienced Neuroradiologists.

    • They are not other people going through ACTATS.

    • The Neuroradiologists all interpreted these scans as part of a clinical trial, long before we set up ACTATS; their opinions are independent of the ACTATS project.

    • Some ACTATS questions do not map back onto the clinical trial questionnaire: some answers were never collected & we do not have an expert opinion.

    • Reader 3 did not review all the cases in the clinical trial: sometimes there is no answer from Reader 3.


  • Once we have 100 completed questionnaires, we aim to anonymize & average the answers provided by all participants; you will be able to see how, on average, all participants answered all questions.


  • Answers are different between expert readers because of the human variability in interpretations.

    • Rather than present an average or agreed score, we take the view that it is important for participants to see where even experts disagree.
    • This should be reassuring when it comes to the clinical scenario: not everyone will agree.
    • This should alert you to the kinds of cases where agreement is straightforward versus where agreement is difficult to achieve & a second or third opinion needs to be sought - it's a reflection of real life.




Thrombectomy networks, affiliations & teaching resources