A method for displaying medical image data. The method includes digitally combining 3D volume visualizations to form a plurality of four-dimensional (4D) volume visualizations representing the 3D volume visualizations over a period of time. The plurality of 4D volume visualizations include first and second 4D volume visualizations. The first 4D volume visualization including the entirety of the common region during a first time period, and the second 4D volume visualization including the entirety of the common region during a different second time period. The method also includes digitally combining the first and second 4D volume visualizations by digitally processing the first and second 4D volume visualizations to generate a modified 4D volume visualization of the entirety of the common region.