A fast calibration method for 3-D tracking of ultrasound images using a spatial localizer.
We have developed a fast calibration method for computing the position and orientation of 2-D ultrasound (US) images in 3-D space where a position sensor is mounted on the US probe. This calibration is required in the fields of 3-D ultrasound and registration of ultrasound with other imaging modalities. Most of the existing calibration methods require a complex and tedious experimental procedure. Our method is simple and it is based on a custom-built phantom. Thirty N-fiducials (markers in the shape of the letter "N") embedded in the phantom provide the basis for our calibration procedure. We calibrated a 3.5-MHz sector phased-array probe with a magnetic position sensor, and we studied the accuracy and precision of our method. A typical calibration procedure requires approximately 2 min. We conclude that we can achieve accurate and precise calibration using a single US image, provided that a large number (approximately ten) of N-fiducials are captured within the US image, enabling a representative sampling of the imaging plane.
Pagoulatos
N
N
Image Computing Systems Laboratory, Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA.
Haynor
D R
DR
Kim
Y
Y
D002138:Calibration / Q000592:standards; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000592:standards*; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000592:standards*; D019047:Phantoms, Imaging / Q000592:standards; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography / Q000379:methods* / Q000592:standards*