US Patent 7251352 Marking 3D locations from ultrasound images

A method for marking three-dimensional (3D) locations from images obtained from an ultrasound imaging system including a transducer, comprising the steps of: tracking the pose of the transducer with respect to an external 3D coordinate system; obtaining a two-dimensional (2D) ultrasound image from the transducer; marking a desired target with a marker on the 2D ultrasound image; and calculating the 3D position of the marker utilizing data from the step of tracking.