RESUMO
PURPOSE: First comparison of two methods of needle insertion: long axis ("in-plane") versus short axis ("out-of-plane") approach, each with and without a prototype needle guidance system (NGS). MATERIALS AND METHODS: 24 medical students without prior experience punctured an ultrasound phantom (transparent except for the decklayer) in four conditions, with the goal of achieving as many accurate punctures as possible within a fixed time. RESULTS: Out-of-plane with NGS led to substantially more hits at first attempt than punctures without NGS (p < 0.001), as well as to a greater total number of hits (p = 0.004), and participants were faster to hit the target the first time (p = 0.009). CONCLUSIONS: Thus, navigation increases accuracy as well as efficiency of ultrasound guided punctures on the phantom. It could prove advantageous in clinical applications for fine needle biopsies, musculoskeletal injections, vascular access, and in regional anesthesia.