An in-vitro study to understand successful free-hand ultrasound guided intervention

AIMS: To describe the optimum conditions for successful free-hand ultrasound guided intervention using an in-vitro experiment. MATERIALS AND METHODS: Optimal free-hand biopsy conditions were determined using targets buried in a purpose-built interventional phantom. The needle/probe distance and probe/phantom surface angle were changed whilst recording the needle track lengths and needle conspicuity. RESULTS: Optimal free-hand conditions included a needle/probe distance of 2-3 cm in combination with a needle/probe angle 55-60 degrees. This enabled excellent needle conspicuity with short needle track length and early needle tip visualization. CONCLUSION: Understanding how to optimize the free-hand conditions will help the interventionalist to obtain greater performance using a variety of puncture devices. This concept is Likely to be particularly important to the novice interventionalist as well as to those teaching the free-hand technique. (C) 2001 The Royal College of Radiologists.