Rights: The University of Waikato Published 21 July 2007 Download

Dr Eli Van Houten at the University of Canterbury talks about the DIET technique and mammography in screening for breast cancer.

Eli and his team are using digital cameras to image the elasticity (or stiffness) of breasts. Cancerous tissue can be ten or up to 100 times stiffer (or less elastic) than normal tissue. Traditional mammograms measure the (radio) density of breast tissue. The density of cancerous and healthy tissue doesn’t always vary much. Another advantage of the DIET technique is that it will make breast examination a much more comfortable procedure.


The mammogram is, you know, its a tried and true and well-tested method for breast cancer screening, and its saved many women’s lives over several years now. DIET would be an improvement on the mammogram. One advantage that DIET has over the mammogram is that DIET is imaging elasticity contrast, whereas a mammogram is actually imaging radio density. Radio density doesn't necessarily vary a great deal between cancerous tissue and healthy tissue. The radio density of cancerous tissue can be the same as healthy tissue, in which case you are not actually looking for obvious image contrast, you are looking at very subtle changes in the structure of the image itself. So you need these highly trained experts, radiographers, to read these mammogram images and try and see if there is cancer in there.

DIET on the other hand is imaging elasticity and the contrast between elasticity in healthy and cancerous tissue is massive. It can be ten times stiffer, it can be up to 100 times stiffer. So if you are looking at a elasticity image and there is cancer in it, ideally you’d see this massive contrast where the cancer is, so we are trying to capitalise on that contrast. Another advantage which is actually very significant is comfort. A lot of woman aren’t attending a regular screening programme using x-ray mammography because they find the imaging process is uncomfortable, and one of the key parts of any screening process is that the images are taken on regular intervals so that radiographers or whoever is looking at the images can compare this year’s image or this month’s image to last years. So if you are skipping and not taking images when you are supposed to or not getting them on a regular basis you are actually removing some of the benefit of a screening methodology. Whereas DIET would be a relatively comfortable imaging process so there wouldn't necessarily be any reason for woman to avoid getting the images taken, so we’re designing the DIET technique to be a screening modality for cancer. As soon as you detect anything of interest in one of these screening images you then go on to a second step which is diagnostic imaging trying to determine what is that that we’ve seen in this screening image.