Contrast-Enhanced Breast Tomosynthesis: Combining the Best of Both Worlds for Better Breast-Cancer Diagnosis

Mammography is currently the most effective breast cancer screening technique. It has been shown by clinical studies that mammography has reduced the mortality by 30~50%. However, mammography is not a perfect technique in that about 30% of breast cancers are missed. A major limit to the sensitivity of conventional mammography is the superimposition of the breast tissue. A mammogram is a two-dimensional (2D) projection image from a three-dimensional breast volume. As a result, the various layers of the breast tissues are superimposed on each other in a single 2D image. For this reason, normal tissue may obscure more deeply buried tumors, making difficult to detect the tumor. Conversely, superimposed normal breast tissues have been known to sometimes produce "false lesions" that appear like a cancerous tumor on a mammogram. This is one reason for the unnecessary call-backs of the patient in 2D mammography. Digital breast tomosynthesis (DBT) is a technique that provides 3D structural information of the breast. By removing the superimposition of breast tissues, DBT potentially can improve the detection and diagnosis of breast cancers, as well as reducing unnecessary call-backs. The diagnostic capability of DBT may be further improved by the use of contrast agent. A contrast agent provides "functional" information of the breast lesion and its usage with 2D digital mammography is being investigated.