Ultrasound-guided interventions with augmented reality in situ visualisation: a proof-of-mechanism phantom study

Background Ultrasound (US) images are currently displayed on monitors, and their understanding needs good orientation skills. Direct overlay of US images onto the according anatomy is possible with augmented reality (AR) technologies. Our purpose was to explore the performance of US-guided needle placement with and without AR in situ US viewing. Methods Three untrained operators and two experienced radiologists performed 200 US-guided punctures: 100 with and 100 without AR in situ US. The punctures were performed in two different phantoms, a leg phantom with soft tissue lesions and a vessel phantom. Time to puncture and number of needle passes were recorded for each puncture. Data are reported as median [range] according to their non-normal distribution. Results AR in situ US resulted in reduced time (median [range], 13 s [3-101] versus 14 s [3-220]) and number of needle passes (median [range], 1 [1-4] versus 1 [1-8]) compared to the conventional technique. The initial gap in performance of untrained versus experienced operators with the conventional US (time, 21.5 s [3-220] versus 10.5 s [3-94] and needle passes 1 [1-8] versus 1 [1, 2]) was reduced to 12.5 s [3-101] versus 13 s [3-100] and 1 [1-4] versus 1 [1-4] when using AR in situ US, respectively. Conclusion AR in situ US could be a potential breakthrough in US applications by simplifying operator's spatial orientation and reducing experience-based differences in performance of US-guided interventions. Further studies are needed to confirm these preliminary phantom results.