From a patient's point of view: A 3D mammogram exam is very similar to a 2D mammogram—both are performed together on the same scanner. Just as with a digital mammogram, the technologist will position you, compress your breast under a paddle, and take images from different angles.
During the 3D portion of the exam, the x-ray arm of the machine makes a quick arc over the breast, taking a series of breast images at a number of angles. The entire procedure should take approximately the same amount of time as a 2D mammogram.
From a technical point of view: The technologist sends your breast images electronically to the radiologist, who will examine breast tissue one layer at a time instead of viewing all the complexities of your breast tissue in a flat image. Fine details can be more clearly visible, less likely to be hidden by the tissue above and below.
This image depicts a tomosynthesis experience from the patient's point of view. A 3D mammogram exam is very similar to a 2D mammogram. In fact, both images are taken at the same time, on the same scanner. And just as with a 2D digital mammogram, the technologist positions the patient, compresses their breast under a paddle and takes images from different angles. During the 3D portion of the exam, the machine's x-ray arm makes a quick arc over the breast, taking a series of images at a number of angles. Tomosynthesis adds no time to the exam, with the entire procedure taking approximately the same amount of time as that of a 2D mammogram.
This image illustrates the differences in 2D and 3D breast imaging. In the "conventional" 2D mammogram (pictured left), there is an apparent area of concern that may require additional studies, like another mammogram or a biopsy. Instead, looking at the same breast tissue in a succession of 3D images (pictured right), doctors can now see that the tissue is, in fact, normal breast tissue that was simply overlapping in the traditional mammogram, thus creating the illusion of an abnormality. In this scenario, the patient likely avoided a callback for an additional mammogram—and the anxiety that goes along with it—thanks to tomosynthesis technology.