Anatomy Guidance for Regional Anaesthesia

Use of regional anaesthesia (RA) and peripheral nerve block (PNB) is growing, although general anaesthesia (GA) is still more common in general surgical practice. Around 65% of all procedures amenable to a regional technique currently use GA, and current UK National Institute of Health and Clinical Excellence (NICE) guidance is that all regional anaesthesia should be performed using ultrasound guidance. However, further increases in regional anaesthesia are expected, as there are significant patient and economic benefits. In particular, the per-procedure costs of regional anaesthesia are considerably less than for general anaesthesia.

Although growing, ultrasound-guided regional anaesthesia is difficult to learn and difficult to perform. There are significant hand-eye-coordination issues as the clinician must simultaneously manipulate both the needle and the ultrasound probe in order to guide the needle to the target. In addition, both the needle and target anatomy can be very difficult to see on the ultrasound image.

The investigators believe that a computer-aided system that highlights key anatomical features on the ultrasound image would make this procedure safer for the patients and simpler for the clinician.

Currently, the leading method for automatic image segmentation uses deep learning, for which many thousands of training images are required. There have been several successes in applying these techniques to medical images, including ultrasound. However, it appears that relatively little attention has been given to automatic segmentation of ultrasound images for regional anaesthesia.

The closest reference to our proposed research describe a method to locate the median nerve in ultrasound images of the forearm. There has also been a Kaggle challenge to segment the brachial plexus nerves in the neck. Multiple anatomical regions can also be segmented at the same time. However, none of these studies are directly applicable to clinical use as they deal only with images captured from healthy volunteers. Neither do they consider how these techniques could be used to aid anaesthetists performing regional anaesthesia in the clinic.