3D tracking and display of mammary ducts

The functional part of the breast consists primarily of epithelial tissue organized in a system consisting of ducts and lobules. Therefore, the ability to display and interpret the organization of this ductal system should be valuable for diagnosing breast abnormalities, as a few clinicians have recently claimed. The ducts converge upon the nipple in a radial pattern. The high contrast between the hypoechoic lumen of a duct and the echogenic surrounding connective tissue makes it possible in some cases to view ductolobular structures below the resolution of the typical scanner. In routine sonography, only a 2D image is seen which employs the relatively poor elevational resolution of the scanhead. Because the ductal system is three dimensional, it is difficult to visualize in two dimensions. A 3D scan can contain multiple ductal systems which can be imaged with better contrast if imaged in cross section in the axial and lateral directions. After identifying and tracing the ducts, they are displayed as a 3D surface. This procedure, if automated and successful, would provide the clinician with a valuable road map to search for abnormalities. The grayscale information contained in the volume of the 3D scan can then be sliced in any orientation or along a curved path to provide a more complete longitudinal view of a given duct.