Assistive artificial intelligence for ultrasound image interpretation in regional anaesthesia: an external validation study

James Simeon Bowness*, David Burckett-St Laurent, Nadia Hernandez, Pearse Keane, Clara Lobo, Eleni Moka, Amit Pawa, Meg Rosenblatt, Nick Sleep, Alasdair Taylor, Glenn Woodworth, Asta Vasalauskaite, J Alison Noble, Helen Higham

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


BACKGROUND: Ultrasonound is used to identify anatomical structures during regional anaesthesia and to guide needle insertion and injection of local anaesthetic. ScanNav Anatomy Peripheral Nerve Block (Intelligent Ultrasound, Cardiff, UK) is an artificial intelligence-based device that produces a colour overlay on real-time B-mode ultrasound to highlight anatomical structures of interest. We evaluated the accuracy of the artificial-intelligence colour overlay and its perceived influence on risk of adverse events or block failure.

METHODS: Ultrasound-guided regional anaesthesia experts acquired 720 videos from 40 volunteers (across nine anatomical regions) without using the device. The artificial-intelligence colour overlay was subsequently applied. Three more experts independently reviewed each video (with the original unmodified video) to assess accuracy of the colour overlay in relation to key anatomical structures (true positive/negative and false positive/negative) and the potential for highlighting to modify perceived risk of adverse events (needle trauma to nerves, arteries, pleura, and peritoneum) or block failure.

RESULTS: The artificial-intelligence models identified the structure of interest in 93.5% of cases (1519/1624), with a false-negative rate of 3.0% (48/1624) and a false-positive rate of 3.5% (57/1624). Highlighting was judged to reduce the risk of unwanted needle trauma to nerves, arteries, pleura, and peritoneum in 62.9-86.4% of cases (302/480 to 345/400), and to increase the risk in 0.0-1.7% (0/160 to 8/480). Risk of block failure was reported to be reduced in 81.3% of scans (585/720) and to be increased in 1.8% (13/720).

CONCLUSIONS: Artificial intelligence-based devices can potentially aid image acquisition and interpretation in ultrasound-guided regional anaesthesia. Further studies are necessary to demonstrate their effectiveness in supporting training and clinical practice.

Original languageEnglish
Pages (from-to)217-225
Number of pages9
JournalBritish Journal of Anaesthesia
Issue number2
Early online date18 Jan 2023
Publication statusPublished - Feb 2023


  • Anatomy
  • Artificial intelligence
  • Machine learning
  • Regional anaesthesia
  • Translational AI
  • Ultrasonography
  • Ultrsound


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