3-DIMENSIONAL IMAGING OF SOLID BREAST-TUMORS WITH ULTRASOUND - PRELIMINARY DATA AND ANALYSIS OF ITS POSSIBLE CONTRIBUTION TO THE UNDERSTANDING OF THE STANDARD 2-DIMENSIONAL SONOGRAPHIC IMAGES

Reconstructed three-dimensional sonographic images are presented from patients having different histological types of breast tumors. Scanning is manual and performed using two-dimensional annular array, sector transducers fitted on a mechanical arm, to provide spatial location. The three-dimensional data are displayed using two different modalities. Planar reformatted sections allow the visualization of planes reconstructed along any direction chosen by the operator. Of particular interest are the reconstructions obtained along equatorial planes of the tumors, i.e. planes parallel to the chest wall and, consequently, to the fibroglandular layer of the breast. Volume rendering is obtained using the shaded-surface visualization technique. Three-dimensional imaging provides new information and allows a better interpretation of the standard two-dimensional images. Planar reformatted sections confirm that ductal carcinomas present margin jagging on all views, including the equatorial section planes. Using the shaded-surface visualization technique, these tumors appear with a spiked outer surface. Thus, the most specific sonographic finding associated with ductal carcinomas may be that margin jagging extends over the entire periphery of the mass. On planar reformatted sections, benign tumors are surrounded by a continuous hyperechogenic rim, i.e. the rim is present irrespective of the section plane orientation. Medullary carcinomas are also surrounded by a hyperechogenic rim. However, a clearly distinctive feature of these lesions is found on planar reformatted sections: the rim is discontinuous on certain section planes. A mass can be considered benign only if its rim is continuous, i.e. if it is present all around the tumor.