Purpose: To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.
Materials and methods: Three different series of biopsy were performed in a phantom: one with a steering device attached to the transducer without needle tracking, simulating the standard ultrasound-guided biopsy procedure (series 1), one freehand in the scan plane using electromagnetic needle tracking (series 2), and one freehand off-the-scan plane using electromagnetic needle tracking (series 3). The phantom contained spheres of 1 cm in diameter filled with red dye. Each time of the phantom surface was perforated counted as an attempt.
Results: 180 biopsies were performed. The mean time spent on each biopsy in series one was 19.9 seconds (SD: 9.1), in series two 34.1 seconds (SD: 17.9) and in series three 34.4 seconds (SD: 14.0). The overall rate of success was: 88 % for in-plane needle-guided biopsy, 87 % for in-plane needle tracking, and 92 % for off-plane needle tracking. No statistically significant difference between the methods was shown.
Conclusion: Needle navigation is a potentially valuable tool for image-guided biopsy with an equal rate of success compared with conventional image-guided biopsy. Furthermore, it enables off-plane image-guided biopsy.
© Georg Thieme Verlag KG Stuttgart · New York.