Trial Information

An Evaluation of Stereoscopic Digital Mammography for Earlier Detection of Breast Cancer and Reduced Rate of Recall

The clinical trial, begun in December, 2004, is being conducted at Emory University. Over
the next three years, we will enroll and image about 2000 women who are at elevated risk for
development of breast cancer (personal or family history of breast cancer) as they come in
for their annual screening examinations. Each participating patient will be imaged with
both systems, and the stereo and standard (non-stereo) images will be read independently by
different mammographers.

A stereoscopic digital mammogram consists of two x-ray images of the breast acquired from
slightly different points of view on a digital mammography unit. The x-ray source is
rotated 10-degrees between the two exposures while the position of the breast remains fixed
in the compression device. The stereo pair of mammograms is viewed on a new
third-generation, high-resolution stereo display workstation that was developed in the first
part of this project. The mammographer views the stereo display wearing lightweight
polarized glasses, enabling him or her to see in depth the internal structure within the
breast. As a result, a subtle lesion that may be obscured by superimposed normal tissue in
a standard 2D image, now becomes visible as the overlying and underlying normal tissue is
separated in depth. Conversely, layers of tissue that may falsely resemble a lesion in a
standard 2D image due to chance superimposition, are seen in the stereo mammogram to lie at
different depths and, thus, will not be mistaken as a lesion.

We anticipate that with stereo mammography the mammographers will detect subtle lesions in
the stereo images that are missed in the non-stereo images. We also expect that there will
be fewer false positive detections with the stereo images compared to the standard images.
Finally, we also expect that the mammographers will be more confident in their judgments of
what they see in the stereo images, resulting in a reduced rate of recall of patients for
further work-up.