Image registration of multiple medical imaging modalities using a multiple degree-of-freedom-encoded fiducial device

A system for registering images from two medical imaging modalities comprising:

• a first imager having a first coordinate frame;
• a second imager having a second coordinate frame;
• and
• a data system,
• wherein the data system includes a non-transitory computer readable medium encoded with computer instructions for performing an image registration process including:
• acquiring a first image from the first imager;
• acquiring a second image from the second imager;
• determining a first coordinate transformation between the first coordinate frame and a fiducial coordinate frame corresponding to a fiducial;
• and
• registering the first image to the second coordinate frame,
• wherein the determining the first coordinate transformation includes:
• providing a current estimated coordinate transformation;
• generating a current estimated image corresponding to the current estimated coordinate transformation;
• determining an error function between the first image and the current estimated image;
• determining a multidimensional derivative corresponding to the current estimated coordinate transformation;
• and
• determining a new estimated coordinate transformation corresponding to the error function and the multidimensional derivative.