Three-dimensional ultrasound imaging using multiple magnetic tracking systems and miniature magnetic sensors

The authors have used several configurations of a commercial 6D magnetic position and orientation measurement system to track an ultrasound scanhead and reconstruct 2D ultrasound images in 3D space. They have measured precision and accuracy with two magnetic sensors working in parallel, and with a miniaturized magnetic sensor. The use of two standard size sensors has shown limited improvement in precision (1.5 mm RMS uncertainty compared with 1.8 mm for a single sensor). The miniature sensor has an average precision of 2.1 mm over its operating range. The miniature sensor has been calibrated with an imaging system and has been used in 3D reconstructions of the stomach and the carotid artery