Correcting probe induced deformation in an ultrasound fusing imaging system

A medical image fusion system comprising:

• a computer capable of processing medical images;
• a source of previously acquired reference images, the images comprising a region of interest in a body having a surface;
• an ultrasound system a probe and configured to acquire ultrasound images;
• a spatial tracking system, coupled to the probe, and arranged to track the spatial location of the probe during image acquisition;
• wherein the computer is adapted to determine from the tracked probe location whether the probe location is at least partially inside the surface of the body shown in a spatially corresponding reference image, and, if so,
• wherein the computer is further adapted to modify the reference image, wherein the modifying of the reference image comprises:
• displaying the probe location outside the surface of the body shown in the reference image;
• redrawing the surface shown in the reference image;
• recasting the appearance of tissue in the reference image so that it is contained within the redrawn surface;
• and
• deforming the appearance of tissue in front of the probe location and inside the redrawn surface in the reference image, wherein deforming is performed in consideration of the density and/or stiffness of the tissue.