These mammograms were performed in 1991 in order that we could examine the effects of breast compression on the image. They show each breast under normal compression and under slightly less compression (typically 0.5cm). Since this technique requires two x-rays and hence double the radiation dose ethics committee approval was requested and granted.

We are developing the concept of differential compression mammography, where mammograms are taken at different compressions and then presented as a movie. The viewer is able to pick out 3D motion and deformation and it is hoped that this will provide information relevant to diagnosis, for example whether certain tissue is soft or hard.

This shows a breast under different amounts of compression. In the upper left of the breast there is a spiculated mass which has spicules that extend to the chest wall. Under compression the mass does not move far whereas tissue close to it on the mammogram moves a large distance. The spicules also extend to the nipple. Note the movement of other features. For example, there is a coarse calcification towards the right of the image which moves some 2cm with a change in compression of only about 0.5cm.