By Marc A. Hertz, MD | Radiology
Much has been written about a new advance in mammography, known as Digital Breast Tomosynthesis, or DBT.
Radiologists have struggled for years to find a means to identify small masses in women with dense, glandular breast architecture- almost half of all women will have a dense breast architecture.
Much as CT scans, which were made commercially available in the 1970’s, enabled us to visualize the internal organs in a three dimensional approach; DBT gives us a similar solution for mammography. Standard mammograms produce a two dimensional, planar, or flat image which averages the density in front, in the middle, and at the far side of the breast.
On these images, the dense tissue appears cloud-like, and uniform. In DBT, areas of different density, and, in particular, small masses, are seen in relief, in sharp focus–they stand out from a monotonous background. It is like the feeling one gets during descent through a cloud, with haze all around, and no clear view of much of anything, compared to the moment we descend below that cloud, and see the ground in sharp focus.
In a DBT exam the radiographic tube moves in an arc around the patient, and takes a series of 11 images in nine seconds-, all at different levels of the breast, each in sharp focus. Generally, this will be performed in a side-to-side oriented image (sagittal plane), both for the left, and the right breast. A supplementary top-to bottom (craniocaudal) image in standard 2-dimensional technique is also taken, also one for the left, and the right breast.
Small calcifications are also seen well in this technique, which were not as well seen with the first generation DBT equipment design. This, and the lower radiation dose, are the main reasons that MKMG decided to wait for the newer technology to become FDA approved, before investing in this revolutionary technology.
These 3-dimensional images are acquired at the same low dose technique, with no additional radiation dose to the patient!
The benefits of DBT are greatest in women with dense architecture, but some benefit will also occur in women without dense tissue. The main benefits include the ability to detect small masses in dense tissue, and a secondary benefit to reduce the numbers of additional mammographic images we used to need to solve problematic mammograms.
You should feel free to discuss this with your Radiologist, or your Mammographic technologist, before your exam. A mammogram can be scheduled by calling the Department of Radiology at 1-888-MKMG-RAD.