Magnetic field-based navigation system for ultrasound guided interventions

Purpose: To describe a new magnetic field-based navigation system for ultra sound-guided interventional procedures. Methods: The navition system suppor ts biopsies either in plane or out of plane. To evaluate the accuracy of th e system, targets in four Standard silicone phantoms were punctured. Six cy stic and six solid lesions were present in every phantom. The success of th e puncture was controlled by aspiration of the content of the lesions, whic h 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 u sing the in plane and out of plane modus in the phantom. In the carcasses a ll 16 lesions were reached in plane, in the out of plane modus two 6 cm dee p lesions were not reached. All other 14 biopsies were successful. Nephrost omy of the not dilated renal pelvis and punction of the gallbladder were su ccessfully carried out. Conclusions: The described navigation system is a p romising tool for fast and safe performance of ultrasound-guided interventi onal procedures.