Magnetic field-based navigation system for ultrasound guided interventions

Purpose: To describe a new magnetic field-based navigation system for ultrasound-guided interventional procedures. Methods: The navition system supports biopsies either in plane or out of plane. To evaluate the accuracy of the system, targets in four Standard silicone phantoms were punctured. Six cystic and six solid lesions were present in every phantom. The success of the puncture was controlled by aspiration of the content of the lesions, which was coloured. Furthermore, liver lesions of different sizes (2-6 mm) and depths (3-6 cm) were produced by injecting a viscous fluid and punctured in three swine carcasses. Functions of the gallbladder and nephrostomies were carried out as well. Results: All 48 targets were successfully punctured using the in plane and out of plane modus in the phantom. In the carcasses all 16 lesions were reached in plane, in the out of plane modus two 6 cm deep lesions were not reached. All other 14 biopsies were successful. Nephrostomy of the not dilated renal pelvis and punction of the gallbladder were successfully carried out. Conclusions: The described navigation system is a promising tool for fast and safe performance of ultrasound-guided interventional procedures.