Methods and systems for motion tracking

17) A method of describing a region of interest (ROI) in a medical image, the method comprising:

• identifying a hard landmark;
• selecting a plurality of soft landmarks proximal to the hard landmark;
• and
• associating a cost function between at least two of the soft landmarks and the hard landmark.

21) A medical imaging system adapted to describe a region of interest (ROI) in a medical image, the system comprising:

• means for identifying a hard landmark;
• means for selecting a plurality of soft landmarks proximal to the hard landmark;
• and
• means for associating a cost function between at least two of the soft landmarks and the hard landmark.

22) A system for tracking motion in an imaging system comprising:

• a display for providing images, the images including an indication of location of a hard landmark of an image;
• processing resources adapted to create a landmark set;
• processing resources adapted to track motion using a cost function of at least two variables for each of at least two landmarks, the at least two landmarks being elements of the landmark set;
• and
• memory adapted to store data for use by the processing resources.

25) A system for tracking motion in an imaging system comprising:

• means for generating a landmark set;
• means for computing a context similarity measurement;
• means for constructing a spatial relationship for a landmark set;
• means for construction of a cost function;
• and
• means for minimizing the cost function and estimating motion.