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Case series
Pioneering artificial intelligence-based real time assistance for intracranial liquid embolization in humans: an initial experience
  1. Yuya Sakakura1,
  2. Osamu Masuo2,
  3. Takeshi Fujimoto3,
  4. Tomoaki Terada4,
  5. Kenichi Kono5,6
    1. 1Department of Neurosurgery, NTT Medical Center Tokyo, Shinagawa-ku, Japan
    2. 2Department of Neuroendovascular Surgery, Yokohama Municipal Citizen's Hospital, Yokohama, Japan
    3. 3Department of Neurosurgery, Numata Neurosurgery & Cardiovascular Hospital, Numata, Gunma, Japan
    4. 4Department of Neurosurgery, Showa University Northern Yokohama Hospital, Yokohama, Kanagawa, Japan
    5. 5Department of Neurosurgery, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan
    6. 6iMed Technologies, Bunkyo-ku, Tokyo, Japan
    1. Correspondence to Dr Yuya Sakakura, Department of Neurosurgery, NTT Medical Center Tokyo, Shinagawa-ku, Japan; yuya.sakakura{at}


    Background Liquid embolization in neuroendovascular procedures carries the risk of embolizing an inappropriate vessel. Operators must pay close attention to multiple vessels during the procedure to avoid ischemic complications. We report our experience with real time artificial intelligence (AI) assisted liquid embolization and evaluate its performance.

    Methods An AI-based system (Neuro-Vascular Assist, iMed technologies, Tokyo, Japan) was used in eight endovascular liquid embolization procedures in two institutions. The software automatically detects liquid embolic agent on biplane fluoroscopy images in real time and notifies operators when the agent reaches a predefined area. Safety, efficacy, and accuracy of the notifications were evaluated using recorded videos.

    Results Onyx or n-butyl-2-cyanoacrylate (NBCA) was used in the treatment of arteriovenous malformation, dural arteriovenous fistula, meningioma, and chronic subdural hematoma. The mean number of true positive and false negative notifications per case was 31.8 and 2.8, respectively. No false positive notifications occurred. The precision and recall of the notifications were 100% and 92.0%, respectively. In 28.3% of the true positive notifications, the operator immediately paused agent injection after receiving the notification, which demonstrates the potential effectiveness of the AI-based system. No adverse events were associated with the notifications.

    Conclusions To the best of our knowledge, this is the first report of real time AI assistance with liquid embolization procedures in humans. The system demonstrated high notification accuracy, safety, and potential clinical usefulness in liquid embolization procedures. Further research is warranted to validate its impact on clinical outcomes. AI-based real time surgical support has the potential to advance neuroendovascular treatment.

    • Liquid Embolic Material
    • Arteriovenous Malformation
    • Technology
    • Fistula
    • Subdural

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    • X @CeoImed

    • Contributors KK conceived the idea of the study and supervised its conduct. YS and KK drafted the original manuscript. OM, TF, TT, and KK were involved in the treatments of the patients in the case series. All authors reviewed the manuscript draft and critically revised it. All authors approved the final version of the manuscript for publication.

    • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

    • Competing interests YS received honoraria from iMed Technologies. OM received lecture fee from Daiichi Sankyo Company. KK is a CEO and holds shares in iMed Technologies.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.