Apparatus and method for optimized search for displacement estimation in elasticity imaging

A system for determining a displacement map between first and second data frames containing RF data values comprising:

• means for indexing the RF data values for the first and second frames with a sample resolution and a display resolution;
• means for creating at least one axial reference line of RF data values having a plurality of positions indexed at the display resolution in the first RF frame;
• using a block-matching algorithm with reference blocks centered on the axial reference line positions, means for determining the best axial displacement estimations for the axial reference line positions in the second RF frame;
• means for storing the axial displacement estimation values for each axial reference line position;
• and
• means for defining an axial reference line position as a transition point, wherein when adjacent axial reference line positions have different values, the axial reference line position having the greater value is a transition point.

A method for performing elasticity imaging between first and second data frames comprising:

• estimating displacements between the first and second data frames for positions along at least one axial reference line in a region of interest in the first data frame;
• defining transition points for positions on the at least one axial reference line;
• tracking the transition points laterally through the region of interest;
• assembling displacement maps from trajectories for each transition point;
• assembling one displacement map from all transition point displacement maps;
• and
• between transition point displacement maps, assigning the area a value belonging to the transition point having the lesser value.